[syzbot] BUG: corrupted list in v9fs_session_close

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 9500fc6e9e60 Merge branch 'for-next/core' into for-kernelci
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=10ca37d9880000
kernel config: https://syzkaller.appspot.com/x/.config?x=b25c9f218686dd5e
dashboard link: https://syzkaller.appspot.com/bug?extid=fbd9516e00e67ffaf87d
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/1363e60652f7/disk-9500fc6e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/fcc4da811bb6/vmlinux-9500fc6e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0b554298f1fa/Image-9500fc6e.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fbd951...@syzkaller.appspotmail.com

list_del corruption. prev->next should be ffff00011fd79548, but was ffff00014c2e3030. (prev=ffff00010c388948)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:61!
Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 3127 Comm: syz-executor.4 Not tainted 6.1.0-rc5-syzkaller-32269-g9500fc6e9e60 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __list_del_entry_valid+0xbc/0xd0 lib/list_debug.c:59
lr : __list_del_entry_valid+0xbc/0xd0 lib/list_debug.c:59
sp : ffff800012ddbcb0
x29: ffff800012ddbcb0 x28: ffff0000c3e69a40 x27: 0000000000000000
x26: 00000000000000c0 x25: 0000000000000002 x24: ffff80000d3ad050
x23: ffff80000d3a9000 x22: 0000000000000000 x21: 0000000000000000
x20: 0000000000000000 x19: ffff00011fd79500 x18: 00000000000000c0
x17: 20747562202c3834 x16: ffff80000dc18158 x15: ffff0000c3e69a40
x14: 0000000000000000 x13: 00000000ffffffff x12: ffff0000c3e69a40
x11: ff808000081c6510 x10: 0000000000000000 x9 : d3c609970caf8000
x8 : d3c609970caf8000 x7 : ffff80000c0b2b74 x6 : 0000000000000000
x5 : 0000000000000080 x4 : 0000000000000001 x3 : 0000000000000000
x2 : ffff0001fefddcc8 x1 : 0000000100000001 x0 : 000000000000006d
Call trace:
__list_del_entry_valid+0xbc/0xd0 lib/list_debug.c:59
__list_del_entry include/linux/list.h:134 [inline]
list_del include/linux/list.h:148 [inline]
v9fs_session_close+0x8c/0xd8 fs/9p/v9fs.c:516
v9fs_kill_super+0x34/0x50 fs/9p/vfs_super.c:226
deactivate_locked_super+0x70/0xe8 fs/super.c:332
deactivate_super+0xd0/0xd4 fs/super.c:363
cleanup_mnt+0x184/0x1c0 fs/namespace.c:1186
__cleanup_mnt+0x20/0x30 fs/namespace.c:1193
task_work_run+0x100/0x148 kernel/task_work.c:179
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
do_notify_resume+0x174/0x1f0 arch/arm64/kernel/signal.c:1127
prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline]
exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline]
el0_svc+0x9c/0x150 arch/arm64/kernel/entry-common.c:638
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584
Code: f001b780 912ce000 aa0803e3 94aa876f (d4210000)
---[ end trace 0000000000000000 ]---


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.