Re: [PATCH] afs: Set vllist to NULL if addr parsing fails

[Christian Brauner <brauner@kernel.org>]

On Mon, 21 Jul 2025 15:26:51 +0100, David Howells wrote:
> syzbot reported a bug in in afs_put_vlserverlist.
> 
>   kAFS: bad VL server IP address
>   BUG: unable to handle page fault for address: fffffffffffffffa
>   ...
>   Oops: Oops: 0002 [#1] SMP KASAN PTI
>   ...
>   RIP: 0010:refcount_dec_and_test include/linux/refcount.h:450 [inline]
>   RIP: 0010:afs_put_vlserverlist+0x3a/0x220 fs/afs/vl_list.c:67
>   ...
>   Call Trace:
>    <TASK>
>    afs_alloc_cell fs/afs/cell.c:218 [inline]
>    afs_lookup_cell+0x12a5/0x1680 fs/afs/cell.c:264
>    afs_cell_init+0x17a/0x380 fs/afs/cell.c:386
>    afs_proc_rootcell_write+0x21f/0x290 fs/afs/proc.c:247
>    proc_simple_write+0x114/0x1b0 fs/proc/generic.c:825
>    pde_write fs/proc/inode.c:330 [inline]
>    proc_reg_write+0x23d/0x330 fs/proc/inode.c:342
>    vfs_write+0x25c/0x1180 fs/read_write.c:682
>    ksys_write+0x12a/0x240 fs/read_write.c:736
>    do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>    do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
>    entry_SYSCALL_64_after_hwframe+0x77/0x7f
> 
> [...]

Applied to the vfs.fixes branch of the vfs/vfs.git tree.
Patches in the vfs.fixes branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs.fixes

[1/1] afs: Set vllist to NULL if addr parsing fails
      https://git.kernel.org/vfs/vfs/c/8b3c655fa240