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@asj asj commented Oct 7, 2015

Kindly consider to pull in these changes. These patch were individually submitted to the mailing list before. Thanks.

asj and others added 30 commits September 29, 2015 16:29
Signed-off-by: Anand Jain <[email protected]>
Signed-off-by: David Sterba <[email protected]>
This will return EIO when __bread() fails to read SB,
instead of EINVAL.

Signed-off-by: Anand Jain <[email protected]>
Signed-off-by: David Sterba <[email protected]>
…INTK defined

error handling logic behaves differently with or without
CONFIG_PRINTK defined, since there are two copies of the same
function which a bit of different logic

One, when CONFIG_PRINTK is defined, code is

__btrfs_std_error(..)
{
::
       save_error_info(fs_info);
       if (sb->s_flags & MS_BORN)
               btrfs_handle_error(fs_info);
}

and two when CONFIG_PRINTK is not defined, the code is

__btrfs_std_error(..)
{
::
       if (sb->s_flags & MS_BORN) {
               save_error_info(fs_info);
               btrfs_handle_error(fs_info);
        }
}

I doubt if this was intentional ? and appear to have caused since
we maintain two copies of the same function and they got diverged
with commits.

Now to decide which logic is correct reviewed changes as below,

 533574c
Commit added two copies of this function

 cf79ffb
Commit made change to only one copy of the function and to the
copy when CONFIG_PRINTK is defined.

To fix this, instead of maintaining two copies of same function
approach, maintain single function, and just put the extra
portion of the code under CONFIG_PRINTK define.

This patch just does that. And keeps code of with CONFIG_PRINTK
defined.

Signed-off-by: Anand Jain <[email protected]>
Signed-off-by: David Sterba <[email protected]>
btrfs_error() and btrfs_std_error() does the same thing
and calls _btrfs_std_error(), so consolidate them together.
And the main motivation is that btrfs_error() is closely
named with btrfs_err(), one handles error action the other
is to log the error, so don't closely name them.

Signed-off-by: Anand Jain <[email protected]>
Suggested-by: David Sterba <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
…ot found

Use btrfs specific error code BTRFS_ERROR_DEV_MISSING_NOT_FOUND instead
of -ENOENT.  Next this removes the logging when user specifies "missing"
and we don't find it in the kernel device list. Logging are for system
events not for user input errors.

Signed-off-by: Anand Jain <[email protected]>
Signed-off-by: David Sterba <[email protected]>
This uses a chunk of code from btrfs_read_dev_super() and creates
a function called btrfs_read_dev_one_super() so that next patch
can use it for scratch superblock.

Signed-off-by: Anand Jain <[email protected]>
[renamed bufhead to bh]
Signed-off-by: David Sterba <[email protected]>
This patch updates and renames btrfs_scratch_superblocks, (which is used
by the replace device thread), with those fixes from the scratch
superblock code section of btrfs_rm_device(). The fixes are:
  Scratch all copies of superblock
  Notify kobject that superblock has been changed
  Update time on the device

So that btrfs_rm_device() can use the function
btrfs_scratch_superblocks() instead of its own scratch code. And further
replace deivce code which similarly releases device back to the system,
will have the fixes from the btrfs device delete.

Signed-off-by: Anand Jain <[email protected]>
[renamed to btrfs_scratch_superblock]
Signed-off-by: David Sterba <[email protected]>
By general rule of thumb there shouldn't be any way that user land
could trigger a kernel operation just by sending wrong arguments.

Here do commit cleanups after user input has been verified.

Signed-off-by: Anand Jain <[email protected]>
Signed-off-by: David Sterba <[email protected]>
Originally the message was not in a helper but ended up there. We should
print error messages from callers instead.

Signed-off-by: Anand Jain <[email protected]>
[reworded subject and changelog]
Signed-off-by: David Sterba <[email protected]>
Signed-off-by: Anand Jain <[email protected]>
[reworded subject and changelog]
Signed-off-by: David Sterba <[email protected]>
To avoid deadlock described in commit 084b6e7 ("btrfs: Fix a
lockdep warning when running xfstest."), we should move kobj stuff out
of dev_replace lock range.

  "It is because the btrfs_kobj_{add/rm}_device() will call memory
  allocation with GFP_KERNEL,
  which may flush fs page cache to free space, waiting for it self to do
  the commit, causing the deadlock.

  To solve the problem, move btrfs_kobj_{add/rm}_device() out of the
  dev_replace lock range, also involing split the
  btrfs_rm_dev_replace_srcdev() function into remove and free parts.

  Now only btrfs_rm_dev_replace_remove_srcdev() is called in dev_replace
  lock range, and kobj_{add/rm} and btrfs_rm_dev_replace_free_srcdev() are
  called out of the lock range."

Signed-off-by: Liu Bo <[email protected]>
Signed-off-by: Anand Jain <[email protected]>
[added lockup description]
Signed-off-by: David Sterba <[email protected]>
This patch will log return value of add/del_qgroup_relation()
and pass the err code of btrfs_run_qgroups to the btrfs_std_error().

Signed-off-by: Anand Jain <[email protected]>
A part of code from btrfs_scan_one_device() is moved to a new
function btrfs_read_disk_super(), so that former function looks
cleaner and moves the code to ensure null terminating label to it as well.
Further there is opportunity to merge various duplicate
code on read disk super. Earlier attempt on this was highlighted
that there was some issues for which there are multiple versions,
however it was not clear what was issue. So until its worked out
we can keep it in a separate function.

Signed-off-by: Anand Jain <[email protected]>
Optional Label may or may not be set, or it might be set at
some time later. However while debugging to search
through the kernel logs the scripts would need the logs to
be consistent, so logs search key words shouldn't depend on the
optional variables, instead fsid is better.

Signed-off-by: Anand Jain <[email protected]>
From the issue diagnosable point of view, log if the device path is
changed.

Signed-off-by: Anand Jain <[email protected]>
looks like oversight, call brelse() when checksum fails.
further down the code in the non error path we do call
brelse() and so we don't see brelse() in the goto error..
paths.

Signed-off-by: Anand Jain <[email protected]>
optimize check for stale device to only be checked when there
is device added or changed. If there is no update to the
device, there is no need to call btrfs_free_stale_device().

Signed-off-by: Anand Jain <[email protected]>
This adds an enhancement to show the seed fsid and its devices
on the btrfs sysfs.

The way sprouting handles fs_devices:
      clone seed fs_devices and add to the fs_uuids
      mem copy seed fs_devices and assign to fs_devices->seed (move dev_list)
      evacuate seed fs_devices contents to hold sprout fs devices contents

  So to be inline with this fs_devices changes during seeding,
  represent seed fsid under the sprout fsid, this is achieved
  by using the kobject_move()
  The end result will be,
    /sys/fs/btrfs/sprout-fsid/seed/level-1-seed-fsid/seed/(if)level-2-seed-fsid

Signed-off-by: Anand Jain <[email protected]>
We need fsid kobject to hold pool attributes however
its created only when fs is mounted. So, this patch
changes the life cycle of the fsid and devices kobjects
/sys/fs/btrfs/<fsid> and /sys/fs/btrfs/<fsid>/devices,
from created and destroyed by mount and unmount event
to created and destroyed by scanned and module-unload
events respectively.

However this does not alter life cycle of fs attributes as such.

Signed-off-by: Anand Jain <[email protected]>
move a section of btrfs_rm_device() code to check for min number
of the devices into the function __check_raid_min_devices()

v2: commit update and title renamed from
    Btrfs: move check for min number of devices to a function

Signed-off-by: Anand Jain <[email protected]>
__check_raid_min_device() which was pealed from btrfs_rm_device()
maintianed its original code to show the block move. This patch
cleans up __check_raid_min_device().

Signed-off-by: Anand Jain <[email protected]>
The patch renames btrfs_dev_replace_find_srcdev() to
btrfs_find_device_by_user_input() and moves it to volumes.c.
so that delete device can use it.

v2: changed title from
    'Btrfs: create rename btrfs_dev_replace_find_srcdev()'
    and commit update

Signed-off-by: Anand Jain <[email protected]>
btrfs_rm_device() has a section of the code which can be replaced
btrfs_find_device_by_user_input()

Signed-off-by: Anand Jain <[email protected]>
The operation of device replace and device delete follows same steps
upto some depth with in btrfs kernel, however they don't share codes.
This enhancement will help replace and delete to share codes.

Btrfs: enhance check device_path in btrfs_find_device_by_user_input()

Signed-off-by: Anand Jain <[email protected]>
With the previous patches now the btrfs_scratch_superblocks()
is ready to be used in btrfs_rm_device() so use it.

Signed-off-by: Anand Jain <[email protected]>
This introduces new ioctl BTRFS_IOC_RM_DEV_V2, which uses
enhanced struct btrfs_ioctl_vol_args_v2 to carry devid as
an user argument.

The patch won't delete the old ioctl interface and remains
backward compatible with user land progs.

Test case/script:
echo "0 $(blockdev --getsz /dev/sdf) linear /dev/sdf 0" | dmsetup create bad_disk
mkfs.btrfs -f -d raid1 -m raid1 /dev/sdd /dev/sde /dev/mapper/bad_disk
mount /dev/sdd /btrfs
dmsetup suspend bad_disk
echo "0 $(blockdev --getsz /dev/sdf) error /dev/sdf 0" | dmsetup load bad_disk
dmsetup resume bad_disk
echo "bad disk failed. now deleting/replacing"
btrfs dev del  3  /btrfs
echo $?
btrfs fi show /btrfs
umount /btrfs
btrfs-show-super /dev/sdd | egrep num_device
dmsetup remove bad_disk
wipefs -a /dev/sdf

Signed-off-by: Anand Jain <[email protected]>
Reported-by: Martin <[email protected]>
kdave pushed a commit that referenced this pull request Oct 13, 2025
syzkaller discovered the following crash: (kernel BUG)

[   44.607039] ------------[ cut here ]------------
[   44.607422] kernel BUG at mm/userfaultfd.c:2067!
[   44.608148] Oops: invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI
[   44.608814] CPU: 1 UID: 0 PID: 2475 Comm: reproducer Not tainted 6.16.0-rc6 #1 PREEMPT(none)
[   44.609635] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   44.610695] RIP: 0010:userfaultfd_release_all+0x3a8/0x460

<snip other registers, drop unreliable trace>

[   44.617726] Call Trace:
[   44.617926]  <TASK>
[   44.619284]  userfaultfd_release+0xef/0x1b0
[   44.620976]  __fput+0x3f9/0xb60
[   44.621240]  fput_close_sync+0x110/0x210
[   44.622222]  __x64_sys_close+0x8f/0x120
[   44.622530]  do_syscall_64+0x5b/0x2f0
[   44.622840]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[   44.623244] RIP: 0033:0x7f365bb3f227

Kernel panics because it detects UFFD inconsistency during
userfaultfd_release_all().  Specifically, a VMA which has a valid pointer
to vma->vm_userfaultfd_ctx, but no UFFD flags in vma->vm_flags.

The inconsistency is caused in ksm_madvise(): when user calls madvise()
with MADV_UNMEARGEABLE on a VMA that is registered for UFFD in MINOR mode,
it accidentally clears all flags stored in the upper 32 bits of
vma->vm_flags.

Assuming x86_64 kernel build, unsigned long is 64-bit and unsigned int and
int are 32-bit wide.  This setup causes the following mishap during the &=
~VM_MERGEABLE assignment.

VM_MERGEABLE is a 32-bit constant of type unsigned int, 0x8000'0000. 
After ~ is applied, it becomes 0x7fff'ffff unsigned int, which is then
promoted to unsigned long before the & operation.  This promotion fills
upper 32 bits with leading 0s, as we're doing unsigned conversion (and
even for a signed conversion, this wouldn't help as the leading bit is 0).
& operation thus ends up AND-ing vm_flags with 0x0000'0000'7fff'ffff
instead of intended 0xffff'ffff'7fff'ffff and hence accidentally clears
the upper 32-bits of its value.

Fix it by changing `VM_MERGEABLE` constant to unsigned long, using the
BIT() macro.

Note: other VM_* flags are not affected: This only happens to the
VM_MERGEABLE flag, as the other VM_* flags are all constants of type int
and after ~ operation, they end up with leading 1 and are thus converted
to unsigned long with leading 1s.

Note 2:
After commit 31defc3 ("userfaultfd: remove (VM_)BUG_ON()s"), this is
no longer a kernel BUG, but a WARNING at the same place:

[   45.595973] WARNING: CPU: 1 PID: 2474 at mm/userfaultfd.c:2067

but the root-cause (flag-drop) remains the same.

[[email protected]: rust bindgen wasn't able to handle BIT(), from Miguel]
  Link: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 7677f7f ("userfaultfd: add minor fault registration mode")
Signed-off-by: Jakub Acs <[email protected]>
Signed-off-by: Miguel Ojeda <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Acked-by: SeongJae Park <[email protected]>
Tested-by: Alice Ryhl <[email protected]>
Tested-by: Miguel Ojeda <[email protected]>
Cc: Xu Xin <[email protected]>
Cc: Chengming Zhou <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Axel Rasmussen <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
kdave pushed a commit that referenced this pull request Oct 13, 2025
net/bridge/br_private.h:1627 suspicious rcu_dereference_protected() usage!
other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
7 locks held by socat/410:
 #0: ffff88800d7a9c90 (sk_lock-AF_INET){+.+.}-{0:0}, at: inet_stream_connect+0x43/0xa0
 #1: ffffffff9a779900 (rcu_read_lock){....}-{1:3}, at: __ip_queue_xmit+0x62/0x1830
 [..]
 #6: ffffffff9a779900 (rcu_read_lock){....}-{1:3}, at: nf_hook.constprop.0+0x8a/0x440

Call Trace:
 lockdep_rcu_suspicious.cold+0x4f/0xb1
 br_vlan_fill_forward_path_pvid+0x32c/0x410 [bridge]
 br_fill_forward_path+0x7a/0x4d0 [bridge]

Use to correct helper, non _rcu variant requires RTNL mutex.

Fixes: bcf2766 ("net: bridge: resolve forwarding path for VLAN tag actions in bridge devices")
Signed-off-by: Eric Woudstra <[email protected]>
Signed-off-by: Florian Westphal <[email protected]>
kdave pushed a commit that referenced this pull request Oct 13, 2025
The refactoring in 4292a1e ("PCI: Refactor distributing available
memory to use loops") switched pci_bus_distribute_available_resources() to
operate on an array of bridge windows. That accidentally looked up bus
resources via pci_bus_resource_n() and then passed those pointers to helper
routines that expect the resource to belong to the device. As soon as we
execute that code, pci_resource_num() warned because the resource wasn't in
the bridge's resource array.

This happens on my AMD Strix Halo machine with Thunderbolt device; the
error message is shown below:

  WARNING: CPU: 6 PID: 272 at drivers/pci/pci.h:471 pci_bus_distribute_available_resources+0x6ad/0x6d0
  CPU: 6 UID: 0 PID: 272 Comm: irq/33-pciehp Not tainted 6.17.0+ #1 PREEMPT(voluntary)
  Hardware name: PELADN YO Series/YO1, BIOS 1.04 05/15/2025
  RIP: 0010:pci_bus_distribute_available_resources+0x6ad/0x6d0
  Call Trace:
   pci_bus_distribute_available_resources+0x590/0x6d0
   pci_bridge_distribute_available_resources+0x62/0xb0
   pci_assign_unassigned_bridge_resources+0x65/0x1b0
   pciehp_configure_device+0x92/0x160
   pciehp_handle_presence_or_link_change+0x1b5/0x350
   pciehp_ist+0x147/0x1c0

Fix the regression by always fetching the resource directly from the bridge
with pci_resource_n(bridge, PCI_BRIDGE_RESOURCES + i). This restores the
original behaviour while keeping the refactored structure.  Then we can
successfully assign resources to the Thunderbolt device.

Fixes: 4292a1e ("PCI: Refactor distributing available memory to use loops")
Reported-by: Kenneth R. Crudup <[email protected]>
Closes: https://lore.kernel.org/r/[email protected]
Signed-off-by: Yangyu Chen <[email protected]>
[bhelgaas: trim timestamps, etc from commit log]
Signed-off-by: Bjorn Helgaas <[email protected]>
Tested-By: Kenneth R. Crudup <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Link: https://patch.msgid.link/[email protected]
kdave pushed a commit that referenced this pull request Oct 13, 2025
Phil reported a boot failure once sheaves become used in commits
59faa4d ("maple_tree: use percpu sheaves for maple_node_cache") and
3accabd ("mm, vma: use percpu sheaves for vm_area_struct cache"):

 BUG: kernel NULL pointer dereference, address: 0000000000000040
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: Oops: 0000 [#1] SMP NOPTI
 CPU: 21 UID: 0 PID: 818 Comm: kworker/u398:0 Not tainted 6.17.0-rc3.slab+ #5 PREEMPT(voluntary)
 Hardware name: Dell Inc. PowerEdge R7425/02MJ3T, BIOS 1.26.0 07/30/2025
 RIP: 0010:__pcs_replace_empty_main+0x44/0x1d0
 Code: ec 08 48 8b 46 10 48 8b 76 08 48 85 c0 74 0b 8b 48 18 85 c9 0f 85 e5 00 00 00 65 48 63 05 e4 ee 50 02 49 8b 84 c6 e0 00 00 00 <4c> 8b 68 40 4c 89 ef e8 b0 81 ff ff 48 89 c5 48 85 c0 74 1d 48 89
 RSP: 0018:ffffd2d10950bdb0 EFLAGS: 00010246
 RAX: 0000000000000000 RBX: ffff8a775dab74b0 RCX: 00000000ffffffff
 RDX: 0000000000000cc0 RSI: ffff8a6800804000 RDI: ffff8a680004e300
 RBP: ffffd2d10950be40 R08: 0000000000000060 R09: ffffffffb9367388
 R10: 00000000000149e8 R11: ffff8a6f87a38000 R12: 0000000000000cc0
 R13: 0000000000000cc0 R14: ffff8a680004e300 R15: 00000000000000c0
 FS:  0000000000000000(0000) GS:ffff8a77a3541000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000040 CR3: 0000000e1aa24000 CR4: 00000000003506f0
 Call Trace:
  <TASK>
  ? srso_return_thunk+0x5/0x5f
  ? vm_area_alloc+0x1e/0x60
  kmem_cache_alloc_noprof+0x4ec/0x5b0
  vm_area_alloc+0x1e/0x60
  create_init_stack_vma+0x26/0x210
  alloc_bprm+0x139/0x200
  kernel_execve+0x4a/0x140
  call_usermodehelper_exec_async+0xd0/0x190
  ? __pfx_call_usermodehelper_exec_async+0x10/0x10
  ret_from_fork+0xf0/0x110
  ? __pfx_call_usermodehelper_exec_async+0x10/0x10
  ret_from_fork_asm+0x1a/0x30
  </TASK>
 Modules linked in:
 CR2: 0000000000000040
 ---[ end trace 0000000000000000 ]---
 RIP: 0010:__pcs_replace_empty_main+0x44/0x1d0
 Code: ec 08 48 8b 46 10 48 8b 76 08 48 85 c0 74 0b 8b 48 18 85 c9 0f 85 e5 00 00 00 65 48 63 05 e4 ee 50 02 49 8b 84 c6 e0 00 00 00 <4c> 8b 68 40 4c 89 ef e8 b0 81 ff ff 48 89 c5 48 85 c0 74 1d 48 89
 RSP: 0018:ffffd2d10950bdb0 EFLAGS: 00010246
 RAX: 0000000000000000 RBX: ffff8a775dab74b0 RCX: 00000000ffffffff
 RDX: 0000000000000cc0 RSI: ffff8a6800804000 RDI: ffff8a680004e300
 RBP: ffffd2d10950be40 R08: 0000000000000060 R09: ffffffffb9367388
 R10: 00000000000149e8 R11: ffff8a6f87a38000 R12: 0000000000000cc0
 R13: 0000000000000cc0 R14: ffff8a680004e300 R15: 00000000000000c0
 FS:  0000000000000000(0000) GS:ffff8a77a3541000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000040 CR3: 0000000e1aa24000 CR4: 00000000003506f0
 Kernel panic - not syncing: Fatal exception
 Kernel Offset: 0x36a00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
 ---[ end Kernel panic - not syncing: Fatal exception ]---

And noted "this is an AMD EPYC 7401 with 8 NUMA nodes configured such
that memory is only on 2 of them."

 # numactl --hardware
 available: 8 nodes (0-7)
 node 0 cpus: 0 8 16 24 32 40 48 56 64 72 80 88
 node 0 size: 0 MB
 node 0 free: 0 MB
 node 1 cpus: 2 10 18 26 34 42 50 58 66 74 82 90
 node 1 size: 31584 MB
 node 1 free: 30397 MB
 node 2 cpus: 4 12 20 28 36 44 52 60 68 76 84 92
 node 2 size: 0 MB
 node 2 free: 0 MB
 node 3 cpus: 6 14 22 30 38 46 54 62 70 78 86 94
 node 3 size: 0 MB
 node 3 free: 0 MB
 node 4 cpus: 1 9 17 25 33 41 49 57 65 73 81 89
 node 4 size: 0 MB
 node 4 free: 0 MB
 node 5 cpus: 3 11 19 27 35 43 51 59 67 75 83 91
 node 5 size: 32214 MB
 node 5 free: 31625 MB
 node 6 cpus: 5 13 21 29 37 45 53 61 69 77 85 93
 node 6 size: 0 MB
 node 6 free: 0 MB
 node 7 cpus: 7 15 23 31 39 47 55 63 71 79 87 95
 node 7 size: 0 MB
 node 7 free: 0 MB

Linus decoded the stacktrace to get_barn() and get_node() and determined
that kmem_cache->node[numa_mem_id()] is NULL.

The problem is due to a wrong assumption that memoryless nodes only
exist on systems with CONFIG_HAVE_MEMORYLESS_NODES, where numa_mem_id()
points to the nearest node that has memory. SLUB has been allocating its
kmem_cache_node structures only on nodes with memory and so it does with
struct node_barn.

For kmem_cache_node, get_partial_node() checks if get_node() result is
not NULL, which I assumed was for protection from a bogus node id passed
to kmalloc_node() but apparently it's also for systems where
numa_mem_id() (used when no specific node is given) might return a
memoryless node.

Fix the sheaves code the same way by checking the result of get_node()
and bailing out if it's NULL. Note that cpus on such memoryless nodes
will have degraded sheaves performance, which can be improved later,
preferably by making numa_mem_id() work properly on such systems.

Fixes: 2d517aa ("slab: add opt-in caching layer of percpu sheaves")
Reported-and-tested-by: Phil Auld <[email protected]>
Closes: https://lore.kernel.org/all/[email protected]/
Analyzed-by: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/all/CAHk-%3Dwg1xK%2BBr%3DFJ5QipVhzCvq7uQVPt5Prze6HDhQQ%[email protected]/
Signed-off-by: Vlastimil Babka <[email protected]>
kdave pushed a commit that referenced this pull request Oct 13, 2025
[BUG]
Syzbot reported an ASSERT() triggered inside scrub:

  BTRFS info (device loop0): scrub: started on devid 1
  assertion failed: !folio_test_partial_kmap(folio) :: 0, in fs/btrfs/scrub.c:697
  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/scrub.c:697!
  Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
  CPU: 0 UID: 0 PID: 6077 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
  RIP: 0010:scrub_stripe_get_kaddr+0x1bb/0x1c0 fs/btrfs/scrub.c:697
  Call Trace:
   <TASK>
   scrub_bio_add_sector fs/btrfs/scrub.c:932 [inline]
   scrub_submit_initial_read+0xf21/0x1120 fs/btrfs/scrub.c:1897
   submit_initial_group_read+0x423/0x5b0 fs/btrfs/scrub.c:1952
   flush_scrub_stripes+0x18f/0x1150 fs/btrfs/scrub.c:1973
   scrub_stripe+0xbea/0x2a30 fs/btrfs/scrub.c:2516
   scrub_chunk+0x2a3/0x430 fs/btrfs/scrub.c:2575
   scrub_enumerate_chunks+0xa70/0x1350 fs/btrfs/scrub.c:2839
   btrfs_scrub_dev+0x6e7/0x10e0 fs/btrfs/scrub.c:3153
   btrfs_ioctl_scrub+0x249/0x4b0 fs/btrfs/ioctl.c:3163
   vfs_ioctl fs/ioctl.c:51 [inline]
   __do_sys_ioctl fs/ioctl.c:597 [inline]
   __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
   </TASK>
  ---[ end trace 0000000000000000 ]---

Which doesn't make much sense, as all the folios we allocated for scrub
should not be highmem.

[CAUSE]
Thankfully syzbot has a detailed kernel config file, showing that
CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP is set to y.

And that debug option will force all folio_test_partial_kmap() to return
true, to improve coverage on highmem tests.

But in our case we really just want to make sure the folios we allocated
are not highmem (and they are indeed not). Such incorrect result from
folio_test_partial_kmap() is just screwing up everything.

[FIX]
Replace folio_test_partial_kmap() to folio_test_highmem() so that we
won't bother those stupid highmem specific debug options.

Fixes: 5fbaae4 ("btrfs: prepare scrub to support bs > ps cases")
Reported-by: [email protected]
Signed-off-by: Qu Wenruo <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
kdave pushed a commit that referenced this pull request Oct 13, 2025
…ce tree

Currently, when building a free space tree at populate_free_space_tree(),
if we are not using the block group tree feature, we always expect to find
block group items (either extent items or a block group item with key type
BTRFS_BLOCK_GROUP_ITEM_KEY) when we search the extent tree with
btrfs_search_slot_for_read(), so we assert that we found an item. However
this expectation is wrong since we can have a new block group created in
the current transaction which is still empty and for which we still have
not added the block group's item to the extent tree, in which case we do
not have any items in the extent tree associated to the block group.

The insertion of a new block group's block group item in the extent tree
happens at btrfs_create_pending_block_groups() when it calls the helper
insert_block_group_item(). This typically is done when a transaction
handle is released, committed or when running delayed refs (either as
part of a transaction commit or when serving tickets for space reservation
if we are low on free space).

So remove the assertion at populate_free_space_tree() even when the block
group tree feature is not enabled and update the comment to mention this
case.

Syzbot reported this with the following stack trace:

  BTRFS info (device loop3 state M): rebuilding free space tree
  assertion failed: ret == 0 :: 0, in fs/btrfs/free-space-tree.c:1115
  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/free-space-tree.c:1115!
  Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
  CPU: 1 UID: 0 PID: 6352 Comm: syz.3.25 Not tainted syzkaller #0 PREEMPT(full)
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
  RIP: 0010:populate_free_space_tree+0x700/0x710 fs/btrfs/free-space-tree.c:1115
  Code: ff ff e8 d3 (...)
  RSP: 0018:ffffc9000430f780 EFLAGS: 00010246
  RAX: 0000000000000043 RBX: ffff88805b709630 RCX: fea61d0e2e79d000
  RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
  RBP: ffffc9000430f8b0 R08: ffffc9000430f4a7 R09: 1ffff92000861e94
  R10: dffffc0000000000 R11: fffff52000861e95 R12: 0000000000000001
  R13: 1ffff92000861f00 R14: dffffc0000000000 R15: 0000000000000000
  FS:  00007f424d9fe6c0(0000) GS:ffff888125afc000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007fd78ad212c0 CR3: 0000000076d68000 CR4: 00000000003526f0
  Call Trace:
   <TASK>
   btrfs_rebuild_free_space_tree+0x1ba/0x6d0 fs/btrfs/free-space-tree.c:1364
   btrfs_start_pre_rw_mount+0x128f/0x1bf0 fs/btrfs/disk-io.c:3062
   btrfs_remount_rw fs/btrfs/super.c:1334 [inline]
   btrfs_reconfigure+0xaed/0x2160 fs/btrfs/super.c:1559
   reconfigure_super+0x227/0x890 fs/super.c:1076
   do_remount fs/namespace.c:3279 [inline]
   path_mount+0xd1a/0xfe0 fs/namespace.c:4027
   do_mount fs/namespace.c:4048 [inline]
   __do_sys_mount fs/namespace.c:4236 [inline]
   __se_sys_mount+0x313/0x410 fs/namespace.c:4213
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
   RIP: 0033:0x7f424e39066a
  Code: d8 64 89 02 (...)
  RSP: 002b:00007f424d9fde68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
  RAX: ffffffffffffffda RBX: 00007f424d9fdef0 RCX: 00007f424e39066a
  RDX: 0000200000000180 RSI: 0000200000000380 RDI: 0000000000000000
  RBP: 0000200000000180 R08: 00007f424d9fdef0 R09: 0000000000000020
  R10: 0000000000000020 R11: 0000000000000246 R12: 0000200000000380
  R13: 00007f424d9fdeb0 R14: 0000000000000000 R15: 00002000000002c0
   </TASK>
  Modules linked in:
  ---[ end trace 0000000000000000 ]---

Reported-by: [email protected]
Link: https://lore.kernel.org/linux-btrfs/[email protected]/
Fixes: a5ed918 ("Btrfs: implement the free space B-tree")
CC: <[email protected]> # 6.1.x: 1961d20: btrfs: fix assertion when building free space tree
CC: <[email protected]> # 6.1.x
Reviewed-by: Qu Wenruo <[email protected]>
Signed-off-by: Filipe Manana <[email protected]>
Signed-off-by: David Sterba <[email protected]>
kdave pushed a commit that referenced this pull request Oct 13, 2025
[BUG]
Syzbot reported an ASSERT() triggered inside scrub:

  BTRFS info (device loop0): scrub: started on devid 1
  assertion failed: !folio_test_partial_kmap(folio) :: 0, in fs/btrfs/scrub.c:697
  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/scrub.c:697!
  Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
  CPU: 0 UID: 0 PID: 6077 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
  RIP: 0010:scrub_stripe_get_kaddr+0x1bb/0x1c0 fs/btrfs/scrub.c:697
  Call Trace:
   <TASK>
   scrub_bio_add_sector fs/btrfs/scrub.c:932 [inline]
   scrub_submit_initial_read+0xf21/0x1120 fs/btrfs/scrub.c:1897
   submit_initial_group_read+0x423/0x5b0 fs/btrfs/scrub.c:1952
   flush_scrub_stripes+0x18f/0x1150 fs/btrfs/scrub.c:1973
   scrub_stripe+0xbea/0x2a30 fs/btrfs/scrub.c:2516
   scrub_chunk+0x2a3/0x430 fs/btrfs/scrub.c:2575
   scrub_enumerate_chunks+0xa70/0x1350 fs/btrfs/scrub.c:2839
   btrfs_scrub_dev+0x6e7/0x10e0 fs/btrfs/scrub.c:3153
   btrfs_ioctl_scrub+0x249/0x4b0 fs/btrfs/ioctl.c:3163
   vfs_ioctl fs/ioctl.c:51 [inline]
   __do_sys_ioctl fs/ioctl.c:597 [inline]
   __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
   </TASK>
  ---[ end trace 0000000000000000 ]---

Which doesn't make much sense, as all the folios we allocated for scrub
should not be highmem.

[CAUSE]
Thankfully syzbot has a detailed kernel config file, showing that
CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP is set to y.

And that debug option will force all folio_test_partial_kmap() to return
true, to improve coverage on highmem tests.

But in our case we really just want to make sure the folios we allocated
are not highmem (and they are indeed not). Such incorrect result from
folio_test_partial_kmap() is just screwing up everything.

[FIX]
Replace folio_test_partial_kmap() to folio_test_highmem() so that we
won't bother those stupid highmem specific debug options.

Fixes: 5fbaae4 ("btrfs: prepare scrub to support bs > ps cases")
Reported-by: [email protected]
Signed-off-by: Qu Wenruo <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
kdave pushed a commit that referenced this pull request Oct 13, 2025
…ce tree

Currently, when building a free space tree at populate_free_space_tree(),
if we are not using the block group tree feature, we always expect to find
block group items (either extent items or a block group item with key type
BTRFS_BLOCK_GROUP_ITEM_KEY) when we search the extent tree with
btrfs_search_slot_for_read(), so we assert that we found an item. However
this expectation is wrong since we can have a new block group created in
the current transaction which is still empty and for which we still have
not added the block group's item to the extent tree, in which case we do
not have any items in the extent tree associated to the block group.

The insertion of a new block group's block group item in the extent tree
happens at btrfs_create_pending_block_groups() when it calls the helper
insert_block_group_item(). This typically is done when a transaction
handle is released, committed or when running delayed refs (either as
part of a transaction commit or when serving tickets for space reservation
if we are low on free space).

So remove the assertion at populate_free_space_tree() even when the block
group tree feature is not enabled and update the comment to mention this
case.

Syzbot reported this with the following stack trace:

  BTRFS info (device loop3 state M): rebuilding free space tree
  assertion failed: ret == 0 :: 0, in fs/btrfs/free-space-tree.c:1115
  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/free-space-tree.c:1115!
  Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
  CPU: 1 UID: 0 PID: 6352 Comm: syz.3.25 Not tainted syzkaller #0 PREEMPT(full)
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
  RIP: 0010:populate_free_space_tree+0x700/0x710 fs/btrfs/free-space-tree.c:1115
  Code: ff ff e8 d3 (...)
  RSP: 0018:ffffc9000430f780 EFLAGS: 00010246
  RAX: 0000000000000043 RBX: ffff88805b709630 RCX: fea61d0e2e79d000
  RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
  RBP: ffffc9000430f8b0 R08: ffffc9000430f4a7 R09: 1ffff92000861e94
  R10: dffffc0000000000 R11: fffff52000861e95 R12: 0000000000000001
  R13: 1ffff92000861f00 R14: dffffc0000000000 R15: 0000000000000000
  FS:  00007f424d9fe6c0(0000) GS:ffff888125afc000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007fd78ad212c0 CR3: 0000000076d68000 CR4: 00000000003526f0
  Call Trace:
   <TASK>
   btrfs_rebuild_free_space_tree+0x1ba/0x6d0 fs/btrfs/free-space-tree.c:1364
   btrfs_start_pre_rw_mount+0x128f/0x1bf0 fs/btrfs/disk-io.c:3062
   btrfs_remount_rw fs/btrfs/super.c:1334 [inline]
   btrfs_reconfigure+0xaed/0x2160 fs/btrfs/super.c:1559
   reconfigure_super+0x227/0x890 fs/super.c:1076
   do_remount fs/namespace.c:3279 [inline]
   path_mount+0xd1a/0xfe0 fs/namespace.c:4027
   do_mount fs/namespace.c:4048 [inline]
   __do_sys_mount fs/namespace.c:4236 [inline]
   __se_sys_mount+0x313/0x410 fs/namespace.c:4213
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
   RIP: 0033:0x7f424e39066a
  Code: d8 64 89 02 (...)
  RSP: 002b:00007f424d9fde68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
  RAX: ffffffffffffffda RBX: 00007f424d9fdef0 RCX: 00007f424e39066a
  RDX: 0000200000000180 RSI: 0000200000000380 RDI: 0000000000000000
  RBP: 0000200000000180 R08: 00007f424d9fdef0 R09: 0000000000000020
  R10: 0000000000000020 R11: 0000000000000246 R12: 0000200000000380
  R13: 00007f424d9fdeb0 R14: 0000000000000000 R15: 00002000000002c0
   </TASK>
  Modules linked in:
  ---[ end trace 0000000000000000 ]---

Reported-by: [email protected]
Link: https://lore.kernel.org/linux-btrfs/[email protected]/
Fixes: a5ed918 ("Btrfs: implement the free space B-tree")
CC: <[email protected]> # 6.1.x: 1961d20: btrfs: fix assertion when building free space tree
CC: <[email protected]> # 6.1.x
Reviewed-by: Qu Wenruo <[email protected]>
Signed-off-by: Filipe Manana <[email protected]>
Signed-off-by: David Sterba <[email protected]>
kdave pushed a commit that referenced this pull request Oct 13, 2025
[BUG]
Syzbot reported an ASSERT() triggered inside scrub:

  BTRFS info (device loop0): scrub: started on devid 1
  assertion failed: !folio_test_partial_kmap(folio) :: 0, in fs/btrfs/scrub.c:697
  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/scrub.c:697!
  Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
  CPU: 0 UID: 0 PID: 6077 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
  RIP: 0010:scrub_stripe_get_kaddr+0x1bb/0x1c0 fs/btrfs/scrub.c:697
  Call Trace:
   <TASK>
   scrub_bio_add_sector fs/btrfs/scrub.c:932 [inline]
   scrub_submit_initial_read+0xf21/0x1120 fs/btrfs/scrub.c:1897
   submit_initial_group_read+0x423/0x5b0 fs/btrfs/scrub.c:1952
   flush_scrub_stripes+0x18f/0x1150 fs/btrfs/scrub.c:1973
   scrub_stripe+0xbea/0x2a30 fs/btrfs/scrub.c:2516
   scrub_chunk+0x2a3/0x430 fs/btrfs/scrub.c:2575
   scrub_enumerate_chunks+0xa70/0x1350 fs/btrfs/scrub.c:2839
   btrfs_scrub_dev+0x6e7/0x10e0 fs/btrfs/scrub.c:3153
   btrfs_ioctl_scrub+0x249/0x4b0 fs/btrfs/ioctl.c:3163
   vfs_ioctl fs/ioctl.c:51 [inline]
   __do_sys_ioctl fs/ioctl.c:597 [inline]
   __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
   </TASK>
  ---[ end trace 0000000000000000 ]---

Which doesn't make much sense, as all the folios we allocated for scrub
should not be highmem.

[CAUSE]
Thankfully syzbot has a detailed kernel config file, showing that
CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP is set to y.

And that debug option will force all folio_test_partial_kmap() to return
true, to improve coverage on highmem tests.

But in our case we really just want to make sure the folios we allocated
are not highmem (and they are indeed not). Such incorrect result from
folio_test_partial_kmap() is just screwing up everything.

[FIX]
Replace folio_test_partial_kmap() to folio_test_highmem() so that we
won't bother those highmem specific debuging options.

Fixes: 5fbaae4 ("btrfs: prepare scrub to support bs > ps cases")
Reported-by: [email protected]
Signed-off-by: Qu Wenruo <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
kdave pushed a commit that referenced this pull request Oct 13, 2025
…ce tree

Currently, when building a free space tree at populate_free_space_tree(),
if we are not using the block group tree feature, we always expect to find
block group items (either extent items or a block group item with key type
BTRFS_BLOCK_GROUP_ITEM_KEY) when we search the extent tree with
btrfs_search_slot_for_read(), so we assert that we found an item. However
this expectation is wrong since we can have a new block group created in
the current transaction which is still empty and for which we still have
not added the block group's item to the extent tree, in which case we do
not have any items in the extent tree associated to the block group.

The insertion of a new block group's block group item in the extent tree
happens at btrfs_create_pending_block_groups() when it calls the helper
insert_block_group_item(). This typically is done when a transaction
handle is released, committed or when running delayed refs (either as
part of a transaction commit or when serving tickets for space reservation
if we are low on free space).

So remove the assertion at populate_free_space_tree() even when the block
group tree feature is not enabled and update the comment to mention this
case.

Syzbot reported this with the following stack trace:

  BTRFS info (device loop3 state M): rebuilding free space tree
  assertion failed: ret == 0 :: 0, in fs/btrfs/free-space-tree.c:1115
  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/free-space-tree.c:1115!
  Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
  CPU: 1 UID: 0 PID: 6352 Comm: syz.3.25 Not tainted syzkaller #0 PREEMPT(full)
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
  RIP: 0010:populate_free_space_tree+0x700/0x710 fs/btrfs/free-space-tree.c:1115
  Code: ff ff e8 d3 (...)
  RSP: 0018:ffffc9000430f780 EFLAGS: 00010246
  RAX: 0000000000000043 RBX: ffff88805b709630 RCX: fea61d0e2e79d000
  RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
  RBP: ffffc9000430f8b0 R08: ffffc9000430f4a7 R09: 1ffff92000861e94
  R10: dffffc0000000000 R11: fffff52000861e95 R12: 0000000000000001
  R13: 1ffff92000861f00 R14: dffffc0000000000 R15: 0000000000000000
  FS:  00007f424d9fe6c0(0000) GS:ffff888125afc000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007fd78ad212c0 CR3: 0000000076d68000 CR4: 00000000003526f0
  Call Trace:
   <TASK>
   btrfs_rebuild_free_space_tree+0x1ba/0x6d0 fs/btrfs/free-space-tree.c:1364
   btrfs_start_pre_rw_mount+0x128f/0x1bf0 fs/btrfs/disk-io.c:3062
   btrfs_remount_rw fs/btrfs/super.c:1334 [inline]
   btrfs_reconfigure+0xaed/0x2160 fs/btrfs/super.c:1559
   reconfigure_super+0x227/0x890 fs/super.c:1076
   do_remount fs/namespace.c:3279 [inline]
   path_mount+0xd1a/0xfe0 fs/namespace.c:4027
   do_mount fs/namespace.c:4048 [inline]
   __do_sys_mount fs/namespace.c:4236 [inline]
   __se_sys_mount+0x313/0x410 fs/namespace.c:4213
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
   RIP: 0033:0x7f424e39066a
  Code: d8 64 89 02 (...)
  RSP: 002b:00007f424d9fde68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
  RAX: ffffffffffffffda RBX: 00007f424d9fdef0 RCX: 00007f424e39066a
  RDX: 0000200000000180 RSI: 0000200000000380 RDI: 0000000000000000
  RBP: 0000200000000180 R08: 00007f424d9fdef0 R09: 0000000000000020
  R10: 0000000000000020 R11: 0000000000000246 R12: 0000200000000380
  R13: 00007f424d9fdeb0 R14: 0000000000000000 R15: 00002000000002c0
   </TASK>
  Modules linked in:
  ---[ end trace 0000000000000000 ]---

Reported-by: [email protected]
Link: https://lore.kernel.org/linux-btrfs/[email protected]/
Fixes: a5ed918 ("Btrfs: implement the free space B-tree")
CC: <[email protected]> # 6.1.x: 1961d20: btrfs: fix assertion when building free space tree
CC: <[email protected]> # 6.1.x
Reviewed-by: Qu Wenruo <[email protected]>
Signed-off-by: Filipe Manana <[email protected]>
Signed-off-by: David Sterba <[email protected]>
kdave pushed a commit that referenced this pull request Oct 13, 2025
[BUG]
Syzbot reported an ASSERT() triggered inside scrub:

  BTRFS info (device loop0): scrub: started on devid 1
  assertion failed: !folio_test_partial_kmap(folio) :: 0, in fs/btrfs/scrub.c:697
  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/scrub.c:697!
  Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
  CPU: 0 UID: 0 PID: 6077 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
  RIP: 0010:scrub_stripe_get_kaddr+0x1bb/0x1c0 fs/btrfs/scrub.c:697
  Call Trace:
   <TASK>
   scrub_bio_add_sector fs/btrfs/scrub.c:932 [inline]
   scrub_submit_initial_read+0xf21/0x1120 fs/btrfs/scrub.c:1897
   submit_initial_group_read+0x423/0x5b0 fs/btrfs/scrub.c:1952
   flush_scrub_stripes+0x18f/0x1150 fs/btrfs/scrub.c:1973
   scrub_stripe+0xbea/0x2a30 fs/btrfs/scrub.c:2516
   scrub_chunk+0x2a3/0x430 fs/btrfs/scrub.c:2575
   scrub_enumerate_chunks+0xa70/0x1350 fs/btrfs/scrub.c:2839
   btrfs_scrub_dev+0x6e7/0x10e0 fs/btrfs/scrub.c:3153
   btrfs_ioctl_scrub+0x249/0x4b0 fs/btrfs/ioctl.c:3163
   vfs_ioctl fs/ioctl.c:51 [inline]
   __do_sys_ioctl fs/ioctl.c:597 [inline]
   __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
   </TASK>
  ---[ end trace 0000000000000000 ]---

Which doesn't make much sense, as all the folios we allocated for scrub
should not be highmem.

[CAUSE]
Thankfully syzbot has a detailed kernel config file, showing that
CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP is set to y.

And that debug option will force all folio_test_partial_kmap() to return
true, to improve coverage on highmem tests.

But in our case we really just want to make sure the folios we allocated
are not highmem (and they are indeed not). Such incorrect result from
folio_test_partial_kmap() is just screwing up everything.

[FIX]
Replace folio_test_partial_kmap() to folio_test_highmem() so that we
won't bother those stupid highmem specific debug options.

Fixes: 5fbaae4 ("btrfs: prepare scrub to support bs > ps cases")
Reported-by: [email protected]
Signed-off-by: Qu Wenruo <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
kdave pushed a commit that referenced this pull request Oct 13, 2025
…ce tree

Currently, when building a free space tree at populate_free_space_tree(),
if we are not using the block group tree feature, we always expect to find
block group items (either extent items or a block group item with key type
BTRFS_BLOCK_GROUP_ITEM_KEY) when we search the extent tree with
btrfs_search_slot_for_read(), so we assert that we found an item. However
this expectation is wrong since we can have a new block group created in
the current transaction which is still empty and for which we still have
not added the block group's item to the extent tree, in which case we do
not have any items in the extent tree associated to the block group.

The insertion of a new block group's block group item in the extent tree
happens at btrfs_create_pending_block_groups() when it calls the helper
insert_block_group_item(). This typically is done when a transaction
handle is released, committed or when running delayed refs (either as
part of a transaction commit or when serving tickets for space reservation
if we are low on free space).

So remove the assertion at populate_free_space_tree() even when the block
group tree feature is not enabled and update the comment to mention this
case.

Syzbot reported this with the following stack trace:

  BTRFS info (device loop3 state M): rebuilding free space tree
  assertion failed: ret == 0 :: 0, in fs/btrfs/free-space-tree.c:1115
  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/free-space-tree.c:1115!
  Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
  CPU: 1 UID: 0 PID: 6352 Comm: syz.3.25 Not tainted syzkaller #0 PREEMPT(full)
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
  RIP: 0010:populate_free_space_tree+0x700/0x710 fs/btrfs/free-space-tree.c:1115
  Code: ff ff e8 d3 (...)
  RSP: 0018:ffffc9000430f780 EFLAGS: 00010246
  RAX: 0000000000000043 RBX: ffff88805b709630 RCX: fea61d0e2e79d000
  RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
  RBP: ffffc9000430f8b0 R08: ffffc9000430f4a7 R09: 1ffff92000861e94
  R10: dffffc0000000000 R11: fffff52000861e95 R12: 0000000000000001
  R13: 1ffff92000861f00 R14: dffffc0000000000 R15: 0000000000000000
  FS:  00007f424d9fe6c0(0000) GS:ffff888125afc000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007fd78ad212c0 CR3: 0000000076d68000 CR4: 00000000003526f0
  Call Trace:
   <TASK>
   btrfs_rebuild_free_space_tree+0x1ba/0x6d0 fs/btrfs/free-space-tree.c:1364
   btrfs_start_pre_rw_mount+0x128f/0x1bf0 fs/btrfs/disk-io.c:3062
   btrfs_remount_rw fs/btrfs/super.c:1334 [inline]
   btrfs_reconfigure+0xaed/0x2160 fs/btrfs/super.c:1559
   reconfigure_super+0x227/0x890 fs/super.c:1076
   do_remount fs/namespace.c:3279 [inline]
   path_mount+0xd1a/0xfe0 fs/namespace.c:4027
   do_mount fs/namespace.c:4048 [inline]
   __do_sys_mount fs/namespace.c:4236 [inline]
   __se_sys_mount+0x313/0x410 fs/namespace.c:4213
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
   RIP: 0033:0x7f424e39066a
  Code: d8 64 89 02 (...)
  RSP: 002b:00007f424d9fde68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
  RAX: ffffffffffffffda RBX: 00007f424d9fdef0 RCX: 00007f424e39066a
  RDX: 0000200000000180 RSI: 0000200000000380 RDI: 0000000000000000
  RBP: 0000200000000180 R08: 00007f424d9fdef0 R09: 0000000000000020
  R10: 0000000000000020 R11: 0000000000000246 R12: 0000200000000380
  R13: 00007f424d9fdeb0 R14: 0000000000000000 R15: 00002000000002c0
   </TASK>
  Modules linked in:
  ---[ end trace 0000000000000000 ]---

Reported-by: [email protected]
Link: https://lore.kernel.org/linux-btrfs/[email protected]/
Fixes: a5ed918 ("Btrfs: implement the free space B-tree")
CC: <[email protected]> # 6.1.x: 1961d20: btrfs: fix assertion when building free space tree
CC: <[email protected]> # 6.1.x
Reviewed-by: Qu Wenruo <[email protected]>
Signed-off-by: Filipe Manana <[email protected]>
Signed-off-by: David Sterba <[email protected]>
kdave pushed a commit that referenced this pull request Oct 16, 2025
…ked_roots()

If fs_info->super_copy or fs_info->super_for_commit allocated failed in
btrfs_get_tree_subvol(), then no need to call btrfs_free_fs_info().
Otherwise btrfs_check_leaked_roots() would access NULL pointer because
fs_info->allocated_roots had not been initialised.

syzkaller reported the following information:
  ------------[ cut here ]------------
  BUG: unable to handle page fault for address: fffffffffffffbb0
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 64c9067 P4D 64c9067 PUD 64cb067 PMD 0
  Oops: Oops: 0000 [#1] SMP KASAN PTI
  CPU: 0 UID: 0 PID: 1402 Comm: syz.1.35 Not tainted 6.15.8 #4 PREEMPT(lazy)
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), (...)
  RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
  RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
  RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline]
  RIP: 0010:refcount_read include/linux/refcount.h:170 [inline]
  RIP: 0010:btrfs_check_leaked_roots+0x18f/0x2c0 fs/btrfs/disk-io.c:1230
  [...]
  Call Trace:
   <TASK>
   btrfs_free_fs_info+0x310/0x410 fs/btrfs/disk-io.c:1280
   btrfs_get_tree_subvol+0x592/0x6b0 fs/btrfs/super.c:2029
   btrfs_get_tree+0x63/0x80 fs/btrfs/super.c:2097
   vfs_get_tree+0x98/0x320 fs/super.c:1759
   do_new_mount+0x357/0x660 fs/namespace.c:3899
   path_mount+0x716/0x19c0 fs/namespace.c:4226
   do_mount fs/namespace.c:4239 [inline]
   __do_sys_mount fs/namespace.c:4450 [inline]
   __se_sys_mount fs/namespace.c:4427 [inline]
   __x64_sys_mount+0x28c/0x310 fs/namespace.c:4427
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0x92/0x180 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x76/0x7e
  RIP: 0033:0x7f032eaffa8d
  [...]

Fixes: 3bb17a2 ("btrfs: add get_tree callback for new mount API")
CC: [email protected] # 6.12+
Reviewed-by: Daniel Vacek <[email protected]>
Reviewed-by: Qu Wenruo <[email protected]>
Signed-off-by: Dewei Meng <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
kdave pushed a commit that referenced this pull request Oct 16, 2025
Since ixgbe_adapter is embedded in devlink, calling devlink_free()
prematurely in the ixgbe_remove() path can lead to UAF. Move devlink_free()
to the end.

KASAN report:

 BUG: KASAN: use-after-free in ixgbe_reset_interrupt_capability+0x140/0x180 [ixgbe]
 Read of size 8 at addr ffff0000adf813e0 by task bash/2095
 CPU: 1 UID: 0 PID: 2095 Comm: bash Tainted: G S  6.17.0-rc2-tnguy.net-queue+ #1 PREEMPT(full)
 [...]
 Call trace:
  show_stack+0x30/0x90 (C)
  dump_stack_lvl+0x9c/0xd0
  print_address_description.constprop.0+0x90/0x310
  print_report+0x104/0x1f0
  kasan_report+0x88/0x180
  __asan_report_load8_noabort+0x20/0x30
  ixgbe_reset_interrupt_capability+0x140/0x180 [ixgbe]
  ixgbe_clear_interrupt_scheme+0xf8/0x130 [ixgbe]
  ixgbe_remove+0x2d0/0x8c0 [ixgbe]
  pci_device_remove+0xa0/0x220
  device_remove+0xb8/0x170
  device_release_driver_internal+0x318/0x490
  device_driver_detach+0x40/0x68
  unbind_store+0xec/0x118
  drv_attr_store+0x64/0xb8
  sysfs_kf_write+0xcc/0x138
  kernfs_fop_write_iter+0x294/0x440
  new_sync_write+0x1fc/0x588
  vfs_write+0x480/0x6a0
  ksys_write+0xf0/0x1e0
  __arm64_sys_write+0x70/0xc0
  invoke_syscall.constprop.0+0xcc/0x280
  el0_svc_common.constprop.0+0xa8/0x248
  do_el0_svc+0x44/0x68
  el0_svc+0x54/0x160
  el0t_64_sync_handler+0xa0/0xe8
  el0t_64_sync+0x1b0/0x1b8

Fixes: a028523 ("ixgbe: add initial devlink support")
Signed-off-by: Koichiro Den <[email protected]>
Tested-by: Rinitha S <[email protected]>
Reviewed-by: Jedrzej Jagielski <[email protected]>
Reviewed-by: Aleksandr Loktionov <[email protected]>
Reviewed-by: Paul Menzel <[email protected]>
Signed-off-by: Jacob Keller <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
kdave pushed a commit that referenced this pull request Oct 16, 2025
Since blamed commit, unregister_netdevice_many_notify() takes the netdev
mutex if the device needs it.

If the device list is too long, this will lock more device mutexes than
lockdep can handle:

unshare -n \
 bash -c 'for i in $(seq 1 100);do ip link add foo$i type dummy;done'

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by kworker/u16:1/69:
 #0: ..148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work
 #1: ..d40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work
 #2: ..bd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net
 #3: ..aa8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch
 #4: ..cb0 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: unregister_netdevice_many_notify
[..]

Add a helper to close and then unlock a list of net_devices.
Devices that are not up have to be skipped - netif_close_many always
removes them from the list without any other actions taken, so they'd
remain in locked state.

Close devices whenever we've used up half of the tracking slots or we
processed entire list without hitting the limit.

Fixes: 7e4d784 ("net: hold netdev instance lock during rtnetlink operations")
Signed-off-by: Florian Westphal <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
kdave pushed a commit that referenced this pull request Oct 17, 2025
…ked_roots()

If fs_info->super_copy or fs_info->super_for_commit allocated failed in
btrfs_get_tree_subvol(), then no need to call btrfs_free_fs_info().
Otherwise btrfs_check_leaked_roots() would access NULL pointer because
fs_info->allocated_roots had not been initialised.

syzkaller reported the following information:
  ------------[ cut here ]------------
  BUG: unable to handle page fault for address: fffffffffffffbb0
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 64c9067 P4D 64c9067 PUD 64cb067 PMD 0
  Oops: Oops: 0000 [#1] SMP KASAN PTI
  CPU: 0 UID: 0 PID: 1402 Comm: syz.1.35 Not tainted 6.15.8 #4 PREEMPT(lazy)
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), (...)
  RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
  RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
  RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline]
  RIP: 0010:refcount_read include/linux/refcount.h:170 [inline]
  RIP: 0010:btrfs_check_leaked_roots+0x18f/0x2c0 fs/btrfs/disk-io.c:1230
  [...]
  Call Trace:
   <TASK>
   btrfs_free_fs_info+0x310/0x410 fs/btrfs/disk-io.c:1280
   btrfs_get_tree_subvol+0x592/0x6b0 fs/btrfs/super.c:2029
   btrfs_get_tree+0x63/0x80 fs/btrfs/super.c:2097
   vfs_get_tree+0x98/0x320 fs/super.c:1759
   do_new_mount+0x357/0x660 fs/namespace.c:3899
   path_mount+0x716/0x19c0 fs/namespace.c:4226
   do_mount fs/namespace.c:4239 [inline]
   __do_sys_mount fs/namespace.c:4450 [inline]
   __se_sys_mount fs/namespace.c:4427 [inline]
   __x64_sys_mount+0x28c/0x310 fs/namespace.c:4427
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0x92/0x180 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x76/0x7e
  RIP: 0033:0x7f032eaffa8d
  [...]

Fixes: 3bb17a2 ("btrfs: add get_tree callback for new mount API")
CC: [email protected] # 6.12+
Reviewed-by: Daniel Vacek <[email protected]>
Reviewed-by: Qu Wenruo <[email protected]>
Signed-off-by: Dewei Meng <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
kdave pushed a commit that referenced this pull request Oct 17, 2025
…ked_roots()

If fs_info->super_copy or fs_info->super_for_commit allocated failed in
btrfs_get_tree_subvol(), then no need to call btrfs_free_fs_info().
Otherwise btrfs_check_leaked_roots() would access NULL pointer because
fs_info->allocated_roots had not been initialised.

syzkaller reported the following information:
  ------------[ cut here ]------------
  BUG: unable to handle page fault for address: fffffffffffffbb0
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 64c9067 P4D 64c9067 PUD 64cb067 PMD 0
  Oops: Oops: 0000 [#1] SMP KASAN PTI
  CPU: 0 UID: 0 PID: 1402 Comm: syz.1.35 Not tainted 6.15.8 #4 PREEMPT(lazy)
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), (...)
  RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
  RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
  RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline]
  RIP: 0010:refcount_read include/linux/refcount.h:170 [inline]
  RIP: 0010:btrfs_check_leaked_roots+0x18f/0x2c0 fs/btrfs/disk-io.c:1230
  [...]
  Call Trace:
   <TASK>
   btrfs_free_fs_info+0x310/0x410 fs/btrfs/disk-io.c:1280
   btrfs_get_tree_subvol+0x592/0x6b0 fs/btrfs/super.c:2029
   btrfs_get_tree+0x63/0x80 fs/btrfs/super.c:2097
   vfs_get_tree+0x98/0x320 fs/super.c:1759
   do_new_mount+0x357/0x660 fs/namespace.c:3899
   path_mount+0x716/0x19c0 fs/namespace.c:4226
   do_mount fs/namespace.c:4239 [inline]
   __do_sys_mount fs/namespace.c:4450 [inline]
   __se_sys_mount fs/namespace.c:4427 [inline]
   __x64_sys_mount+0x28c/0x310 fs/namespace.c:4427
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0x92/0x180 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x76/0x7e
  RIP: 0033:0x7f032eaffa8d
  [...]

Fixes: 3bb17a2 ("btrfs: add get_tree callback for new mount API")
CC: [email protected] # 6.12+
Reviewed-by: Daniel Vacek <[email protected]>
Reviewed-by: Qu Wenruo <[email protected]>
Signed-off-by: Dewei Meng <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
kdave pushed a commit that referenced this pull request Oct 20, 2025
Expand the prefault memory selftest to add a regression test for a KVM bug
where KVM's retry logic would result in (breakable) deadlock due to the
memslot deletion waiting on prefaulting to release SRCU, and prefaulting
waiting on the memslot to fully disappear (KVM uses a two-step process to
delete memslots, and KVM x86 retries page faults if a to-be-deleted, a.k.a.
INVALID, memslot is encountered).

To exercise concurrent memslot remove, spawn a second thread to initiate
memslot removal at roughly the same time as prefaulting.  Test memslot
removal for all testcases, i.e. don't limit concurrent removal to only the
success case.  There are essentially three prefault scenarios (so far)
that are of interest:

 1. Success
 2. ENOENT due to no memslot
 3. EAGAIN due to INVALID memslot

For all intents and purposes, #1 and #2 are mutually exclusive, or rather,
easier to test via separate testcases since writing to non-existent memory
is trivial.  But for #3, making it mutually exclusive with #1 _or_ #2 is
actually more complex than testing memslot removal for all scenarios.  The
only requirement to let memslot removal coexist with other scenarios is a
way to guarantee a stable result, e.g. that the "no memslot" test observes
ENOENT, not EAGAIN, for the final checks.

So, rather than make memslot removal mutually exclusive with the ENOENT
scenario, simply restore the memslot and retry prefaulting.  For the "no
memslot" case, KVM_PRE_FAULT_MEMORY should be idempotent, i.e. should
always fail with ENOENT regardless of how many times userspace attempts
prefaulting.

Pass in both the base GPA and the offset (instead of the "full" GPA) so
that the worker can recreate the memslot.

Signed-off-by: Yan Zhao <[email protected]>
Co-developed-by: Sean Christopherson <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
kdave pushed a commit that referenced this pull request Oct 20, 2025
Another day, another syzkaller bug. KVM erroneously allows userspace to
pend vCPU events for a vCPU that hasn't been initialized yet, leading to
KVM interpreting a bunch of uninitialized garbage for routing /
injecting the exception.

In one case the injection code and the hyp disagree on whether the vCPU
has a 32bit EL1 and put the vCPU into an illegal mode for AArch64,
tripping the BUG() in exception_target_el() during the next injection:

  kernel BUG at arch/arm64/kvm/inject_fault.c:40!
  Internal error: Oops - BUG: 00000000f2000800 [#1]  SMP
  CPU: 3 UID: 0 PID: 318 Comm: repro Not tainted 6.17.0-rc4-00104-g10fd0285305d #6 PREEMPT
  Hardware name: linux,dummy-virt (DT)
  pstate: 21402009 (nzCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
  pc : exception_target_el+0x88/0x8c
  lr : pend_serror_exception+0x18/0x13c
  sp : ffff800082f03a10
  x29: ffff800082f03a10 x28: ffff0000cb132280 x27: 0000000000000000
  x26: 0000000000000000 x25: ffff0000c2a99c20 x24: 0000000000000000
  x23: 0000000000008000 x22: 0000000000000002 x21: 0000000000000004
  x20: 0000000000008000 x19: ffff0000c2a99c20 x18: 0000000000000000
  x17: 0000000000000000 x16: 0000000000000000 x15: 00000000200000c0
  x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
  x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
  x8 : ffff800082f03af8 x7 : 0000000000000000 x6 : 0000000000000000
  x5 : ffff800080f621f0 x4 : 0000000000000000 x3 : 0000000000000000
  x2 : 000000000040009b x1 : 0000000000000003 x0 : ffff0000c2a99c20
  Call trace:
   exception_target_el+0x88/0x8c (P)
   kvm_inject_serror_esr+0x40/0x3b4
   __kvm_arm_vcpu_set_events+0xf0/0x100
   kvm_arch_vcpu_ioctl+0x180/0x9d4
   kvm_vcpu_ioctl+0x60c/0x9f4
   __arm64_sys_ioctl+0xac/0x104
   invoke_syscall+0x48/0x110
   el0_svc_common.constprop.0+0x40/0xe0
   do_el0_svc+0x1c/0x28
   el0_svc+0x34/0xf0
   el0t_64_sync_handler+0xa0/0xe4
   el0t_64_sync+0x198/0x19c
  Code: f946bc01 b4fffe61 9101e020 17fffff2 (d4210000)

Reject the ioctls outright as no sane VMM would call these before
KVM_ARM_VCPU_INIT anyway. Even if it did the exception would've been
thrown away by the eventual reset of the vCPU's state.

Cc: [email protected] # 6.17
Fixes: b7b27fa ("arm/arm64: KVM: Add KVM_GET/SET_VCPU_EVENTS")
Signed-off-by: Oliver Upton <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>
kdave pushed a commit that referenced this pull request Oct 20, 2025
cxl EDAC calls cxl_feature_info() to get the feature information and
if the hardware has no Features support, cxlfs may be passed in as
NULL.

[   51.957498] BUG: kernel NULL pointer dereference, address: 0000000000000008
[   51.965571] #PF: supervisor read access in kernel mode
[   51.971559] #PF: error_code(0x0000) - not-present page
[   51.977542] PGD 17e4f6067 P4D 0
[   51.981384] Oops: Oops: 0000 [#1] SMP NOPTI
[   51.986300] CPU: 49 UID: 0 PID: 3782 Comm: systemd-udevd Not tainted 6.17.0dj
test+ torvalds#64 PREEMPT(voluntary)
[   51.997355] Hardware name: <removed>
[   52.009790] RIP: 0010:cxl_feature_info+0xa/0x80 [cxl_core]

Add a check for cxlfs before dereferencing it and return -EOPNOTSUPP if
there is no cxlfs created due to no hardware support.

Fixes: eb5dfcb ("cxl: Add support to handle user feature commands for set feature")
Reviewed-by: Davidlohr Bueso <[email protected]>
Reviewed-by: Alison Schofield <[email protected]>
Signed-off-by: Dave Jiang <[email protected]>
kdave pushed a commit that referenced this pull request Oct 20, 2025
…/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.18, take #1

Improvements and bug fixes:

- Fix the handling of ZCR_EL2 in NV VMs
  ([email protected])

- Pick the correct translation regime when doing a PTW on
  the back of a SEA ([email protected])

- Prevent userspace from injecting an event into a vcpu that isn't
  initialised yet ([email protected])

- Move timer save/restore to the sysreg handling code, fixing EL2 timer
  access in the process ([email protected])

- Add FGT-based trapping of MDSCR_EL1 to reduce the overhead of debug
  ([email protected])

- Fix trapping configuration when the host isn't GICv3
  ([email protected])

- Improve the detection of HCR_EL2.E2H being RES1
  ([email protected])

- Drop a spurious 'break' statement in the S1 PTW
  ([email protected])

- Don't try to access SPE when owned by EL3
  ([email protected])

Documentation updates:

- Document the failure modes of event injection
  ([email protected])

- Document that a GICv3 guest can be created on a GICv5 host
  with FEAT_GCIE_LEGACY ([email protected])

Selftest improvements:

- Add a selftest for the effective value of HCR_EL2.AMO
  ([email protected])

- Address build warning in the timer selftest when building
  with clang ([email protected])

- Teach irq_fd selftests about non-x86 architectures
  ([email protected])

- Add missing sysregs to the set_id_regs selftest
  ([email protected])

- Fix vcpu allocation in the vgic_lpi_stress selftest
  ([email protected])

- Correctly enable interrupts in the vgic_lpi_stress selftest
  ([email protected])
kdave pushed a commit that referenced this pull request Oct 21, 2025
Calling intotify_show_fdinfo() on fd watching an overlayfs inode, while
the overlayfs is being unmounted, can lead to dereferencing NULL ptr.

This issue was found by syzkaller.

Race Condition Diagram:

Thread 1                           Thread 2
--------                           --------

generic_shutdown_super()
 shrink_dcache_for_umount
  sb->s_root = NULL

                    |
                    |             vfs_read()
                    |              inotify_fdinfo()
                    |               * inode get from mark *
                    |               show_mark_fhandle(m, inode)
                    |                exportfs_encode_fid(inode, ..)
                    |                 ovl_encode_fh(inode, ..)
                    |                  ovl_check_encode_origin(inode)
                    |                   * deref i_sb->s_root *
                    |
                    |
                    v
 fsnotify_sb_delete(sb)

Which then leads to:

[   32.133461] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI
[   32.134438] KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037]
[   32.135032] CPU: 1 UID: 0 PID: 4468 Comm: systemd-coredum Not tainted 6.17.0-rc6 torvalds#22 PREEMPT(none)

<snip registers, unreliable trace>

[   32.143353] Call Trace:
[   32.143732]  ovl_encode_fh+0xd5/0x170
[   32.144031]  exportfs_encode_inode_fh+0x12f/0x300
[   32.144425]  show_mark_fhandle+0xbe/0x1f0
[   32.145805]  inotify_fdinfo+0x226/0x2d0
[   32.146442]  inotify_show_fdinfo+0x1c5/0x350
[   32.147168]  seq_show+0x530/0x6f0
[   32.147449]  seq_read_iter+0x503/0x12a0
[   32.148419]  seq_read+0x31f/0x410
[   32.150714]  vfs_read+0x1f0/0x9e0
[   32.152297]  ksys_read+0x125/0x240

IOW ovl_check_encode_origin derefs inode->i_sb->s_root, after it was set
to NULL in the unmount path.

Fix it by protecting calling exportfs_encode_fid() from
show_mark_fhandle() with s_umount lock.

This form of fix was suggested by Amir in [1].

[1]: https://lore.kernel.org/all/CAOQ4uxhbDwhb+2Brs1UdkoF0a3NSdBAOQPNfEHjahrgoKJpLEw@mail.gmail.com/

Fixes: c45beeb ("ovl: support encoding fid from inode with no alias")
Signed-off-by: Jakub Acs <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Amir Goldstein <[email protected]>
Cc: Miklos Szeredi <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Jan Kara <[email protected]>
kdave pushed a commit that referenced this pull request Oct 23, 2025
The syzbot report a crash:

  Oops: general protection fault, probably for non-canonical address 0xfbd5a5d5a0000003: 0000 [#1] SMP KASAN NOPTI
  KASAN: maybe wild-memory-access in range [0xdead4ead00000018-0xdead4ead0000001f]
  CPU: 1 UID: 0 PID: 6949 Comm: syz.0.335 Not tainted syzkaller #0 PREEMPT(full)
  Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
  RIP: 0010:smc_diag_msg_common_fill net/smc/smc_diag.c:44 [inline]
  RIP: 0010:__smc_diag_dump.constprop.0+0x3ca/0x2550 net/smc/smc_diag.c:89
  Call Trace:
   <TASK>
   smc_diag_dump_proto+0x26d/0x420 net/smc/smc_diag.c:217
   smc_diag_dump+0x27/0x90 net/smc/smc_diag.c:234
   netlink_dump+0x539/0xd30 net/netlink/af_netlink.c:2327
   __netlink_dump_start+0x6d6/0x990 net/netlink/af_netlink.c:2442
   netlink_dump_start include/linux/netlink.h:341 [inline]
   smc_diag_handler_dump+0x1f9/0x240 net/smc/smc_diag.c:251
   __sock_diag_cmd net/core/sock_diag.c:249 [inline]
   sock_diag_rcv_msg+0x438/0x790 net/core/sock_diag.c:285
   netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552
   netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
   netlink_unicast+0x5a7/0x870 net/netlink/af_netlink.c:1346
   netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896
   sock_sendmsg_nosec net/socket.c:714 [inline]
   __sock_sendmsg net/socket.c:729 [inline]
   ____sys_sendmsg+0xa95/0xc70 net/socket.c:2614
   ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668
   __sys_sendmsg+0x16d/0x220 net/socket.c:2700
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
   </TASK>

The process like this:

               (CPU1)              |             (CPU2)
  ---------------------------------|-------------------------------
  inet_create()                    |
    // init clcsock to NULL        |
    sk = sk_alloc()                |
                                   |
    // unexpectedly change clcsock |
    inet_init_csk_locks()          |
                                   |
    // add sk to hash table        |
    smc_inet_init_sock()           |
      smc_sk_init()                |
        smc_hash_sk()              |
                                   | // traverse the hash table
                                   | smc_diag_dump_proto
                                   |   __smc_diag_dump()
                                   |     // visit wrong clcsock
                                   |     smc_diag_msg_common_fill()
    // alloc clcsock               |
    smc_create_clcsk               |
      sock_create_kern             |

With CONFIG_DEBUG_LOCK_ALLOC=y, the smc->clcsock is unexpectedly changed
in inet_init_csk_locks(). The INET_PROTOSW_ICSK flag is no need by smc,
just remove it.

After removing the INET_PROTOSW_ICSK flag, this patch alse revert
commit 6fd27ea ("net/smc: fix lacks of icsk_syn_mss with IPPROTO_SMC")
to avoid casting smc_sock to inet_connection_sock.

Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=f775be4458668f7d220e
Tested-by: [email protected]
Fixes: d25a92c ("net/smc: Introduce IPPROTO_SMC")
Signed-off-by: Wang Liang <[email protected]>
Reviewed-by: Kuniyuki Iwashima <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Reviewed-by: D. Wythe <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
kdave pushed a commit that referenced this pull request Oct 23, 2025
When we do mlx5e_detach_netdev() we eventually disable blocking events
notifier, among those events are IPsec MPV events from IB to core.

So before disabling those blocking events, make sure to also unregister
the devcom device and mark all this device operations as complete,
in order to prevent the other device from using invalid netdev
during future devcom events which could cause the trace below.

BUG: kernel NULL pointer dereference, address: 0000000000000010
PGD 146427067 P4D 146427067 PUD 146488067 PMD 0
Oops: Oops: 0000 [#1] SMP
CPU: 1 UID: 0 PID: 7735 Comm: devlink Tainted: GW 6.12.0-rc6_for_upstream_min_debug_2024_11_08_00_46 #1
Tainted: [W]=WARN
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:mlx5_devcom_comp_set_ready+0x5/0x40 [mlx5_core]
Code: 00 01 48 83 05 23 32 1e 00 01 41 b8 ed ff ff ff e9 60 ff ff ff 48 83 05 00 32 1e 00 01 eb e3 66 0f 1f 44 00 00 0f 1f 44 00 00 <48> 8b 47 10 48 83 05 5f 32 1e 00 01 48 8b 50 40 48 85 d2 74 05 40
RSP: 0018:ffff88811a5c35f8 EFLAGS: 00010206
RAX: ffff888106e8ab80 RBX: ffff888107d7e200 RCX: ffff88810d6f0a00
RDX: ffff88810d6f0a00 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffff88811a17e620 R08: 0000000000000040 R09: 0000000000000000
R10: ffff88811a5c3618 R11: 0000000de85d51bd R12: ffff88811a17e600
R13: ffff88810d6f0a00 R14: 0000000000000000 R15: ffff8881034bda80
FS:  00007f27bdf89180(0000) GS:ffff88852c880000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000010 CR3: 000000010f159005 CR4: 0000000000372eb0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ? __die+0x20/0x60
 ? page_fault_oops+0x150/0x3e0
 ? exc_page_fault+0x74/0x130
 ? asm_exc_page_fault+0x22/0x30
 ? mlx5_devcom_comp_set_ready+0x5/0x40 [mlx5_core]
 mlx5e_devcom_event_mpv+0x42/0x60 [mlx5_core]
 mlx5_devcom_send_event+0x8c/0x170 [mlx5_core]
 blocking_event+0x17b/0x230 [mlx5_core]
 notifier_call_chain+0x35/0xa0
 blocking_notifier_call_chain+0x3d/0x60
 mlx5_blocking_notifier_call_chain+0x22/0x30 [mlx5_core]
 mlx5_core_mp_event_replay+0x12/0x20 [mlx5_core]
 mlx5_ib_bind_slave_port+0x228/0x2c0 [mlx5_ib]
 mlx5_ib_stage_init_init+0x664/0x9d0 [mlx5_ib]
 ? idr_alloc_cyclic+0x50/0xb0
 ? __kmalloc_cache_noprof+0x167/0x340
 ? __kmalloc_noprof+0x1a7/0x430
 __mlx5_ib_add+0x34/0xd0 [mlx5_ib]
 mlx5r_probe+0xe9/0x310 [mlx5_ib]
 ? kernfs_add_one+0x107/0x150
 ? __mlx5_ib_add+0xd0/0xd0 [mlx5_ib]
 auxiliary_bus_probe+0x3e/0x90
 really_probe+0xc5/0x3a0
 ? driver_probe_device+0x90/0x90
 __driver_probe_device+0x80/0x160
 driver_probe_device+0x1e/0x90
 __device_attach_driver+0x7d/0x100
 bus_for_each_drv+0x80/0xd0
 __device_attach+0xbc/0x1f0
 bus_probe_device+0x86/0xa0
 device_add+0x62d/0x830
 __auxiliary_device_add+0x3b/0xa0
 ? auxiliary_device_init+0x41/0x90
 add_adev+0xd1/0x150 [mlx5_core]
 mlx5_rescan_drivers_locked+0x21c/0x300 [mlx5_core]
 esw_mode_change+0x6c/0xc0 [mlx5_core]
 mlx5_devlink_eswitch_mode_set+0x21e/0x640 [mlx5_core]
 devlink_nl_eswitch_set_doit+0x60/0xe0
 genl_family_rcv_msg_doit+0xd0/0x120
 genl_rcv_msg+0x180/0x2b0
 ? devlink_get_from_attrs_lock+0x170/0x170
 ? devlink_nl_eswitch_get_doit+0x290/0x290
 ? devlink_nl_pre_doit_port_optional+0x50/0x50
 ? genl_family_rcv_msg_dumpit+0xf0/0xf0
 netlink_rcv_skb+0x54/0x100
 genl_rcv+0x24/0x40
 netlink_unicast+0x1fc/0x2d0
 netlink_sendmsg+0x1e4/0x410
 __sock_sendmsg+0x38/0x60
 ? sockfd_lookup_light+0x12/0x60
 __sys_sendto+0x105/0x160
 ? __sys_recvmsg+0x4e/0x90
 __x64_sys_sendto+0x20/0x30
 do_syscall_64+0x4c/0x100
 entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7f27bc91b13a
Code: bb 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 8b 05 fa 96 2c 00 45 89 c9 4c 63 d1 48 63 ff 85 c0 75 15 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 76 f3 c3 0f 1f 40 00 41 55 41 54 4d 89 c5 55
RSP: 002b:00007fff369557e8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000009c54b10 RCX: 00007f27bc91b13a
RDX: 0000000000000038 RSI: 0000000009c54b10 RDI: 0000000000000006
RBP: 0000000009c54920 R08: 00007f27bd0030e0 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001
 </TASK>
Modules linked in: mlx5_vdpa vringh vhost_iotlb vdpa xt_MASQUERADE nf_conntrack_netlink nfnetlink iptable_nat xt_addrtype xt_conntrack nf_nat br_netfilter rpcsec_gss_krb5 auth_rpcgss oid_registry overlay rpcrdma rdma_ucm ib_iser libiscsi ib_umad scsi_transport_iscsi ib_ipoib rdma_cm iw_cm ib_cm mlx5_fwctl mlx5_ib ib_uverbs ib_core mlx5_core
CR2: 0000000000000010

Fixes: 82f9378 ("net/mlx5: Handle IPsec steering upon master unbind/bind")
Signed-off-by: Patrisious Haddad <[email protected]>
Reviewed-by: Leon Romanovsky <[email protected]>
Signed-off-by: Tariq Toukan <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
kdave pushed a commit that referenced this pull request Oct 27, 2025
The original code causes a circular locking dependency found by lockdep.

======================================================
WARNING: possible circular locking dependency detected
6.16.0-rc6-lgci-xe-xe-pw-151626v3+ #1 Tainted: G S   U
------------------------------------------------------
xe_fault_inject/5091 is trying to acquire lock:
ffff888156815688 ((work_completion)(&(&devcd->del_wk)->work)){+.+.}-{0:0}, at: __flush_work+0x25d/0x660

but task is already holding lock:

ffff888156815620 (&devcd->mutex){+.+.}-{3:3}, at: dev_coredump_put+0x3f/0xa0
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&devcd->mutex){+.+.}-{3:3}:
       mutex_lock_nested+0x4e/0xc0
       devcd_data_write+0x27/0x90
       sysfs_kf_bin_write+0x80/0xf0
       kernfs_fop_write_iter+0x169/0x220
       vfs_write+0x293/0x560
       ksys_write+0x72/0xf0
       __x64_sys_write+0x19/0x30
       x64_sys_call+0x2bf/0x2660
       do_syscall_64+0x93/0xb60
       entry_SYSCALL_64_after_hwframe+0x76/0x7e
-> #1 (kn->active#236){++++}-{0:0}:
       kernfs_drain+0x1e2/0x200
       __kernfs_remove+0xae/0x400
       kernfs_remove_by_name_ns+0x5d/0xc0
       remove_files+0x54/0x70
       sysfs_remove_group+0x3d/0xa0
       sysfs_remove_groups+0x2e/0x60
       device_remove_attrs+0xc7/0x100
       device_del+0x15d/0x3b0
       devcd_del+0x19/0x30
       process_one_work+0x22b/0x6f0
       worker_thread+0x1e8/0x3d0
       kthread+0x11c/0x250
       ret_from_fork+0x26c/0x2e0
       ret_from_fork_asm+0x1a/0x30
-> #0 ((work_completion)(&(&devcd->del_wk)->work)){+.+.}-{0:0}:
       __lock_acquire+0x1661/0x2860
       lock_acquire+0xc4/0x2f0
       __flush_work+0x27a/0x660
       flush_delayed_work+0x5d/0xa0
       dev_coredump_put+0x63/0xa0
       xe_driver_devcoredump_fini+0x12/0x20 [xe]
       devm_action_release+0x12/0x30
       release_nodes+0x3a/0x120
       devres_release_all+0x8a/0xd0
       device_unbind_cleanup+0x12/0x80
       device_release_driver_internal+0x23a/0x280
       device_driver_detach+0x14/0x20
       unbind_store+0xaf/0xc0
       drv_attr_store+0x21/0x50
       sysfs_kf_write+0x4a/0x80
       kernfs_fop_write_iter+0x169/0x220
       vfs_write+0x293/0x560
       ksys_write+0x72/0xf0
       __x64_sys_write+0x19/0x30
       x64_sys_call+0x2bf/0x2660
       do_syscall_64+0x93/0xb60
       entry_SYSCALL_64_after_hwframe+0x76/0x7e
other info that might help us debug this:
Chain exists of: (work_completion)(&(&devcd->del_wk)->work) --> kn->active#236 --> &devcd->mutex
 Possible unsafe locking scenario:
       CPU0                    CPU1
       ----                    ----
  lock(&devcd->mutex);
                               lock(kn->active#236);
                               lock(&devcd->mutex);
  lock((work_completion)(&(&devcd->del_wk)->work));
 *** DEADLOCK ***
5 locks held by xe_fault_inject/5091:
 #0: ffff8881129f9488 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x72/0xf0
 #1: ffff88810c755078 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x123/0x220
 #2: ffff8881054811a0 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0x55/0x280
 #3: ffff888156815620 (&devcd->mutex){+.+.}-{3:3}, at: dev_coredump_put+0x3f/0xa0
 #4: ffffffff8359e020 (rcu_read_lock){....}-{1:2}, at: __flush_work+0x72/0x660
stack backtrace:
CPU: 14 UID: 0 PID: 5091 Comm: xe_fault_inject Tainted: G S   U              6.16.0-rc6-lgci-xe-xe-pw-151626v3+ #1 PREEMPT_{RT,(lazy)}
Tainted: [S]=CPU_OUT_OF_SPEC, [U]=USER
Hardware name: Micro-Star International Co., Ltd. MS-7D25/PRO Z690-A DDR4(MS-7D25), BIOS 1.10 12/13/2021
Call Trace:
 <TASK>
 dump_stack_lvl+0x91/0xf0
 dump_stack+0x10/0x20
 print_circular_bug+0x285/0x360
 check_noncircular+0x135/0x150
 ? register_lock_class+0x48/0x4a0
 __lock_acquire+0x1661/0x2860
 lock_acquire+0xc4/0x2f0
 ? __flush_work+0x25d/0x660
 ? mark_held_locks+0x46/0x90
 ? __flush_work+0x25d/0x660
 __flush_work+0x27a/0x660
 ? __flush_work+0x25d/0x660
 ? trace_hardirqs_on+0x1e/0xd0
 ? __pfx_wq_barrier_func+0x10/0x10
 flush_delayed_work+0x5d/0xa0
 dev_coredump_put+0x63/0xa0
 xe_driver_devcoredump_fini+0x12/0x20 [xe]
 devm_action_release+0x12/0x30
 release_nodes+0x3a/0x120
 devres_release_all+0x8a/0xd0
 device_unbind_cleanup+0x12/0x80
 device_release_driver_internal+0x23a/0x280
 ? bus_find_device+0xa8/0xe0
 device_driver_detach+0x14/0x20
 unbind_store+0xaf/0xc0
 drv_attr_store+0x21/0x50
 sysfs_kf_write+0x4a/0x80
 kernfs_fop_write_iter+0x169/0x220
 vfs_write+0x293/0x560
 ksys_write+0x72/0xf0
 __x64_sys_write+0x19/0x30
 x64_sys_call+0x2bf/0x2660
 do_syscall_64+0x93/0xb60
 ? __f_unlock_pos+0x15/0x20
 ? __x64_sys_getdents64+0x9b/0x130
 ? __pfx_filldir64+0x10/0x10
 ? do_syscall_64+0x1a2/0xb60
 ? clear_bhb_loop+0x30/0x80
 ? clear_bhb_loop+0x30/0x80
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x76e292edd574
Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d d5 ea 0e 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89
RSP: 002b:00007fffe247a828 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000076e292edd574
RDX: 000000000000000c RSI: 00006267f6306063 RDI: 000000000000000b
RBP: 000000000000000c R08: 000076e292fc4b20 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00006267f6306063
R13: 000000000000000b R14: 00006267e6859c00 R15: 000076e29322a000
 </TASK>
xe 0000:03:00.0: [drm] Xe device coredump has been deleted.

Fixes: 01daccf ("devcoredump : Serialize devcd_del work")
Cc: Mukesh Ojha <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Johannes Berg <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: Danilo Krummrich <[email protected]>
Cc: [email protected]
Cc: [email protected] # v6.1+
Signed-off-by: Maarten Lankhorst <[email protected]>
Cc: Matthew Brost <[email protected]>
Acked-by: Mukesh Ojha <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
kdave pushed a commit that referenced this pull request Oct 27, 2025
Since commit 0c17270 ("net: sysfs: Implement is_visible for
phys_(port_id, port_name, switch_id)"), __dev_change_net_namespace() can
hit WARN_ON() when trying to change owner of a file that isn't visible.
See the trace below:

 WARNING: CPU: 6 PID: 2938 at net/core/dev.c:12410 __dev_change_net_namespace+0xb89/0xc30
 CPU: 6 UID: 0 PID: 2938 Comm: incusd Not tainted 6.17.1-1-mainline #1 PREEMPT(full)  4b783b4a638669fb644857f484487d17cb45ed1f
 Hardware name: Framework Laptop 13 (AMD Ryzen 7040Series)/FRANMDCP07, BIOS 03.07 02/19/2025
 RIP: 0010:__dev_change_net_namespace+0xb89/0xc30
 [...]
 Call Trace:
  <TASK>
  ? if6_seq_show+0x30/0x50
  do_setlink.isra.0+0xc7/0x1270
  ? __nla_validate_parse+0x5c/0xcc0
  ? security_capable+0x94/0x1a0
  rtnl_newlink+0x858/0xc20
  ? update_curr+0x8e/0x1c0
  ? update_entity_lag+0x71/0x80
  ? sched_balance_newidle+0x358/0x450
  ? psi_task_switch+0x113/0x2a0
  ? __pfx_rtnl_newlink+0x10/0x10
  rtnetlink_rcv_msg+0x346/0x3e0
  ? sched_clock+0x10/0x30
  ? __pfx_rtnetlink_rcv_msg+0x10/0x10
  netlink_rcv_skb+0x59/0x110
  netlink_unicast+0x285/0x3c0
  ? __alloc_skb+0xdb/0x1a0
  netlink_sendmsg+0x20d/0x430
  ____sys_sendmsg+0x39f/0x3d0
  ? import_iovec+0x2f/0x40
  ___sys_sendmsg+0x99/0xe0
  __sys_sendmsg+0x8a/0xf0
  do_syscall_64+0x81/0x970
  ? __sys_bind+0xe3/0x110
  ? syscall_exit_work+0x143/0x1b0
  ? do_syscall_64+0x244/0x970
  ? sock_alloc_file+0x63/0xc0
  ? syscall_exit_work+0x143/0x1b0
  ? do_syscall_64+0x244/0x970
  ? alloc_fd+0x12e/0x190
  ? put_unused_fd+0x2a/0x70
  ? do_sys_openat2+0xa2/0xe0
  ? syscall_exit_work+0x143/0x1b0
  ? do_syscall_64+0x244/0x970
  ? exc_page_fault+0x7e/0x1a0
  entry_SYSCALL_64_after_hwframe+0x76/0x7e
 [...]
  </TASK>

Fix this by checking is_visible() before trying to touch the attribute.

Fixes: 303a427 ("sysfs: add sysfs_group{s}_change_owner()")
Fixes: 0c17270 ("net: sysfs: Implement is_visible for phys_(port_id, port_name, switch_id)")
Reported-by: Cynthia <[email protected]>
Closes: https://lore.kernel.org/netdev/01070199e22de7f8-28f711ab-d3f1-46d9-b9a0-048ab05eb09b-000000@eu-central-1.amazonses.com/
Signed-off-by: Fernando Fernandez Mancera <[email protected]>
Reviewed-by: Jakub Kicinski <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
kdave pushed a commit that referenced this pull request Oct 27, 2025
This commit address a kernel panic issue that can happen if Userspace
tries to partially unmap a GPU virtual region (aka drm_gpuva).
The VM_BIND interface allows partial unmapping of a BO.

Panthor driver pre-allocates memory for the new drm_gpuva structures
that would be needed for the map/unmap operation, done using drm_gpuvm
layer. It expected that only one new drm_gpuva would be needed on umap
but a partial unmap can require 2 new drm_gpuva and that's why it
ended up doing a NULL pointer dereference causing a kernel panic.

Following dump was seen when partial unmap was exercised.
 Unable to handle kernel NULL pointer dereference at virtual address 0000000000000078
 Mem abort info:
   ESR = 0x0000000096000046
   EC = 0x25: DABT (current EL), IL = 32 bits
   SET = 0, FnV = 0
   EA = 0, S1PTW = 0
   FSC = 0x06: level 2 translation fault
 Data abort info:
   ISV = 0, ISS = 0x00000046, ISS2 = 0x00000000
   CM = 0, WnR = 1, TnD = 0, TagAccess = 0
   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
 user pgtable: 4k pages, 48-bit VAs, pgdp=000000088a863000
 [000000000000078] pgd=080000088a842003, p4d=080000088a842003, pud=0800000884bf5003, pmd=0000000000000000
 Internal error: Oops: 0000000096000046 [#1] PREEMPT SMP
 <snip>
 pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 pc : panthor_gpuva_sm_step_remap+0xe4/0x330 [panthor]
 lr : panthor_gpuva_sm_step_remap+0x6c/0x330 [panthor]
 sp : ffff800085d43970
 x29: ffff800085d43970 x28: ffff00080363e440 x27: ffff0008090c6000
 x26: 0000000000000030 x25: ffff800085d439f8 x24: ffff00080d402000
 x23: ffff800085d43b60 x22: ffff800085d439e0 x21: ffff00080abdb180
 x20: 0000000000000000 x19: 0000000000000000 x18: 0000000000000010
 x17: 6e656c202c303030 x16: 3666666666646466 x15: 393d61766f69202c
 x14: 312d3d7361203a70 x13: 303030323d6e656c x12: ffff80008324bf58
 x11: 0000000000000003 x10: 0000000000000002 x9 : ffff8000801a6a9c
 x8 : ffff00080360b300 x7 : 0000000000000000 x6 : 000000088aa35fc7
 x5 : fff1000080000000 x4 : ffff8000842ddd30 x3 : 0000000000000001
 x2 : 0000000100000000 x1 : 0000000000000001 x0 : 0000000000000078
 Call trace:
  panthor_gpuva_sm_step_remap+0xe4/0x330 [panthor]
  op_remap_cb.isra.22+0x50/0x80
  __drm_gpuvm_sm_unmap+0x10c/0x1c8
  drm_gpuvm_sm_unmap+0x40/0x60
  panthor_vm_exec_op+0xb4/0x3d0 [panthor]
  panthor_vm_bind_exec_sync_op+0x154/0x278 [panthor]
  panthor_ioctl_vm_bind+0x160/0x4a0 [panthor]
  drm_ioctl_kernel+0xbc/0x138
  drm_ioctl+0x240/0x500
  __arm64_sys_ioctl+0xb0/0xf8
  invoke_syscall+0x4c/0x110
  el0_svc_common.constprop.1+0x98/0xf8
  do_el0_svc+0x24/0x38
  el0_svc+0x40/0xf8
  el0t_64_sync_handler+0xa0/0xc8
  el0t_64_sync+0x174/0x178

Signed-off-by: Akash Goel <[email protected]>
Reviewed-by: Boris Brezillon <[email protected]>
Reviewed-by: Liviu Dudau <[email protected]>
Fixes: 647810e ("drm/panthor: Add the MMU/VM logical block")
Reviewed-by: Steven Price <[email protected]>
Signed-off-by: Steven Price <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
kdave pushed a commit that referenced this pull request Nov 1, 2025
Imported dma-bufs also have obj->resv != &obj->_resv.  So we should
check both this condition in addition to flags for handling the
_NO_SHARE case.

Fixes this splat that was reported with IRIS video playback:

    ------------[ cut here ]------------
    WARNING: CPU: 3 PID: 2040 at drivers/gpu/drm/msm/msm_gem.c:1127 msm_gem_free_object+0x1f8/0x264 [msm]
    CPU: 3 UID: 1000 PID: 2040 Comm: .gnome-shell-wr Not tainted 6.17.0-rc7 #1 PREEMPT
    pstate: 81400005 (Nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
    pc : msm_gem_free_object+0x1f8/0x264 [msm]
    lr : msm_gem_free_object+0x138/0x264 [msm]
    sp : ffff800092a1bb30
    x29: ffff800092a1bb80 x28: ffff800092a1bce8 x27: ffffbc702dbdbe08
    x26: 0000000000000008 x25: 0000000000000009 x24: 00000000000000a6
    x23: ffff00083c72f850 x22: ffff00083c72f868 x21: ffff00087e69f200
    x20: ffff00087e69f330 x19: ffff00084d157ae0 x18: 0000000000000000
    x17: 0000000000000000 x16: ffffbc704bd46b80 x15: 0000ffffd0959540
    x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
    x11: ffffbc702e6cdb48 x10: 0000000000000000 x9 : 000000000000003f
    x8 : ffff800092a1ba90 x7 : 0000000000000000 x6 : 0000000000000020
    x5 : ffffbc704bd46c40 x4 : fffffdffe102cf60 x3 : 0000000000400032
    x2 : 0000000000020000 x1 : ffff00087e6978e8 x0 : ffff00087e6977e8
    Call trace:
     msm_gem_free_object+0x1f8/0x264 [msm] (P)
     drm_gem_object_free+0x1c/0x30 [drm]
     drm_gem_object_handle_put_unlocked+0x138/0x150 [drm]
     drm_gem_object_release_handle+0x5c/0xcc [drm]
     drm_gem_handle_delete+0x68/0xbc [drm]
     drm_gem_close_ioctl+0x34/0x40 [drm]
     drm_ioctl_kernel+0xc0/0x130 [drm]
     drm_ioctl+0x360/0x4e0 [drm]
     __arm64_sys_ioctl+0xac/0x104
     invoke_syscall+0x48/0x104
     el0_svc_common.constprop.0+0x40/0xe0
     do_el0_svc+0x1c/0x28
     el0_svc+0x34/0xec
     el0t_64_sync_handler+0xa0/0xe4
     el0t_64_sync+0x198/0x19c
    ---[ end trace 0000000000000000 ]---
    ------------[ cut here ]------------

Reported-by: Stephan Gerhold <[email protected]>
Fixes: de651b6 ("drm/msm: Fix refcnt underflow in error path")
Signed-off-by: Rob Clark <[email protected]>
Tested-by: Stephan Gerhold <[email protected]>
Tested-by: Luca Weiss <[email protected]>
Tested-by: Bryan O'Donoghue <[email protected]> # qrb5165-rb5
Patchwork: https://patchwork.freedesktop.org/patch/676273/
Message-ID: <[email protected]>
kdave pushed a commit that referenced this pull request Nov 1, 2025
The following splat was reported:

    Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010
    Mem abort info:
      ESR = 0x0000000096000004
      EC = 0x25: DABT (current EL), IL = 32 bits
      SET = 0, FnV = 0
      EA = 0, S1PTW = 0
      FSC = 0x04: level 0 translation fault
    Data abort info:
      ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
      CM = 0, WnR = 0, TnD = 0, TagAccess = 0
      GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
    user pgtable: 4k pages, 48-bit VAs, pgdp=00000008d0fd8000
    [0000000000000010] pgd=0000000000000000, p4d=0000000000000000
    Internal error: Oops: 0000000096000004 [#1]  SMP
    CPU: 5 UID: 1000 PID: 149076 Comm: Xwayland Tainted: G S                  6.16.0-rc2-00809-g0b6974bb4134-dirty torvalds#367 PREEMPT
    Tainted: [S]=CPU_OUT_OF_SPEC
    Hardware name: Qualcomm Technologies, Inc. SM8650 HDK (DT)
    pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
    pc : build_detached_freelist+0x28/0x224
    lr : kmem_cache_free_bulk.part.0+0x38/0x244
    sp : ffff000a508c7a20
    x29: ffff000a508c7a20 x28: ffff000a508c7d50 x27: ffffc4e49d16f350
    x26: 0000000000000058 x25: 00000000fffffffc x24: 0000000000000000
    x23: ffff00098c4e1450 x22: 00000000fffffffc x21: 0000000000000000
    x20: ffff000a508c7af8 x19: 0000000000000002 x18: 00000000000003e8
    x17: ffff000809523850 x16: ffff000809523820 x15: 0000000000401640
    x14: ffff000809371140 x13: 0000000000000130 x12: ffff0008b5711e30
    x11: 00000000001058fa x10: 0000000000000a80 x9 : ffff000a508c7940
    x8 : ffff000809371ba0 x7 : 781fffe033087fff x6 : 0000000000000000
    x5 : ffff0008003cd000 x4 : 781fffe033083fff x3 : ffff000a508c7af8
    x2 : fffffdffc0000000 x1 : 0001000000000000 x0 : ffff0008001a6a00
    Call trace:
     build_detached_freelist+0x28/0x224 (P)
     kmem_cache_free_bulk.part.0+0x38/0x244
     kmem_cache_free_bulk+0x10/0x1c
     msm_iommu_pagetable_prealloc_cleanup+0x3c/0xd0
     msm_vma_job_free+0x30/0x240
     msm_ioctl_vm_bind+0x1d0/0x9a0
     drm_ioctl_kernel+0x84/0x104
     drm_ioctl+0x358/0x4d4
     __arm64_sys_ioctl+0x8c/0xe0
     invoke_syscall+0x44/0x100
     el0_svc_common.constprop.0+0x3c/0xe0
     do_el0_svc+0x18/0x20
     el0_svc+0x30/0x100
     el0t_64_sync_handler+0x104/0x130
     el0t_64_sync+0x170/0x174
    Code: aa0203f5 b26287e2 f2dfbfe2 aa0303f4 (f8737ab6)
    ---[ end trace 0000000000000000 ]---

Since msm_vma_job_free() is called directly from the ioctl, this looks
like an error path cleanup issue.  Which I think results from
prealloc_cleanup() called without a preceding successful
prealloc_allocate() call.  So handle that case better.

Reported-by: Connor Abbott <[email protected]>
Signed-off-by: Rob Clark <[email protected]>
Patchwork: https://patchwork.freedesktop.org/patch/678677/
Message-ID: <[email protected]>
kdave pushed a commit that referenced this pull request Nov 1, 2025
Do not block PCI config accesses through pci_cfg_access_lock() when
executing the s390 variant of PCI error recovery: Acquire just
device_lock() instead of pci_dev_lock() as powerpc's EEH and
generig PCI AER processing do.

During error recovery testing a pair of tasks was reported to be hung:

mlx5_core 0000:00:00.1: mlx5_health_try_recover:338:(pid 5553): health recovery flow aborted, PCI reads still not working
INFO: task kmcheck:72 blocked for more than 122 seconds.
      Not tainted 5.14.0-570.12.1.bringup7.el9.s390x #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kmcheck         state:D stack:0     pid:72    tgid:72    ppid:2      flags:0x00000000
Call Trace:
 [<000000065256f030>] __schedule+0x2a0/0x590
 [<000000065256f356>] schedule+0x36/0xe0
 [<000000065256f572>] schedule_preempt_disabled+0x22/0x30
 [<0000000652570a94>] __mutex_lock.constprop.0+0x484/0x8a8
 [<000003ff800673a4>] mlx5_unload_one+0x34/0x58 [mlx5_core]
 [<000003ff8006745c>] mlx5_pci_err_detected+0x94/0x140 [mlx5_core]
 [<0000000652556c5a>] zpci_event_attempt_error_recovery+0xf2/0x398
 [<0000000651b9184a>] __zpci_event_error+0x23a/0x2c0
INFO: task kworker/u1664:6:1514 blocked for more than 122 seconds.
      Not tainted 5.14.0-570.12.1.bringup7.el9.s390x #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u1664:6 state:D stack:0     pid:1514  tgid:1514  ppid:2      flags:0x00000000
Workqueue: mlx5_health0000:00:00.0 mlx5_fw_fatal_reporter_err_work [mlx5_core]
Call Trace:
 [<000000065256f030>] __schedule+0x2a0/0x590
 [<000000065256f356>] schedule+0x36/0xe0
 [<0000000652172e28>] pci_wait_cfg+0x80/0xe8
 [<0000000652172f94>] pci_cfg_access_lock+0x74/0x88
 [<000003ff800916b6>] mlx5_vsc_gw_lock+0x36/0x178 [mlx5_core]
 [<000003ff80098824>] mlx5_crdump_collect+0x34/0x1c8 [mlx5_core]
 [<000003ff80074b62>] mlx5_fw_fatal_reporter_dump+0x6a/0xe8 [mlx5_core]
 [<0000000652512242>] devlink_health_do_dump.part.0+0x82/0x168
 [<0000000652513212>] devlink_health_report+0x19a/0x230
 [<000003ff80075a12>] mlx5_fw_fatal_reporter_err_work+0xba/0x1b0 [mlx5_core]

No kernel log of the exact same error with an upstream kernel is
available - but the very same deadlock situation can be constructed there,
too:

- task: kmcheck
  mlx5_unload_one() tries to acquire devlink lock while the PCI error
  recovery code has set pdev->block_cfg_access by way of
  pci_cfg_access_lock()
- task: kworker
  mlx5_crdump_collect() tries to set block_cfg_access through
  pci_cfg_access_lock() while devlink_health_report() had acquired
  the devlink lock.

A similar deadlock situation can be reproduced by requesting a
crdump with
  > devlink health dump show pci/<BDF> reporter fw_fatal

while PCI error recovery is executed on the same <BDF> physical function
by mlx5_core's pci_error_handlers. On s390 this can be injected with
  > zpcictl --reset-fw <BDF>

Tests with this patch failed to reproduce that second deadlock situation,
the devlink command is rejected with "kernel answers: Permission denied" -
and we get a kernel log message of:

mlx5_core 1ed0:00:00.1: mlx5_crdump_collect:50:(pid 254382): crdump: failed to lock vsc gw err -5

because the config read of VSC_SEMAPHORE is rejected by the underlying
hardware.

Two prior attempts to address this issue have been discussed and
ultimately rejected [see link], with the primary argument that s390's
implementation of PCI error recovery is imposing restrictions that
neither powerpc's EEH nor PCI AER handling need. Tests show that PCI
error recovery on s390 is running to completion even without blocking
access to PCI config space.

Link: https://lore.kernel.org/all/[email protected]/
Cc: [email protected]
Fixes: 4cdf2f4 ("s390/pci: implement minimal PCI error recovery")
Reviewed-by: Niklas Schnelle <[email protected]>
Signed-off-by: Gerd Bayer <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>
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