Hello,
syzbot found the following issue on:
HEAD commit: 6e2fd6534337 Linux 5.15.213
git tree: linux-5.15.y
console output:
https://syzkaller.appspot.com/x/log.txt?x=16ed13b9580000
kernel config:
https://syzkaller.appspot.com/x/.config?x=f161cbc9aef65db0
dashboard link:
https://syzkaller.appspot.com/bug?extid=f2ebbe9cbd4016909a50
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image:
https://storage.googleapis.com/syzbot-assets/d7b46606b13d/disk-6e2fd653.raw.xz
vmlinux:
https://storage.googleapis.com/syzbot-assets/da120fdeb081/vmlinux-6e2fd653.xz
kernel image:
https://storage.googleapis.com/syzbot-assets/3c2643457e3f/bzImage-6e2fd653.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by:
syzbot+f2ebbe...@syzkaller.appspotmail.com
Kernel panic - not syncing: KASAN: panic_on_warn set ...
CPU: 0 PID: 4186 Comm: syz-executor Tainted: G B syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
<TASK>
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
panic+0x2f8/0x850 kernel/panic.c:309
check_panic_on_warn+0x80/0xa0 kernel/panic.c:229
end_report+0x6d/0xf0 mm/kasan/report.c:121
__kasan_report mm/kasan/report.c:441 [inline]
kasan_report+0x102/0x130 mm/kasan/report.c:451
check_region_inline mm/kasan/generic.c:-1 [inline]
kasan_check_range+0x235/0x290 mm/kasan/generic.c:189
instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:111 [inline]
__refcount_add include/linux/refcount.h:193 [inline]
__refcount_inc include/linux/refcount.h:250 [inline]
refcount_inc include/linux/refcount.h:267 [inline]
kref_get include/linux/kref.h:45 [inline]
svc_get include/linux/sunrpc/svc.h:108 [inline]
nfsd_shutdown_threads+0x89/0x1a0 fs/nfsd/nfssvc.c:641
nfsd_umount+0x3e/0xc0 fs/nfsd/nfsctl.c:1411
deactivate_locked_super+0x93/0xf0 fs/super.c:335
cleanup_mnt+0x426/0x4d0 fs/namespace.c:1148
task_work_run+0x125/0x1a0 kernel/task_work.c:188
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f526a4d4257
Code: a2 c7 05 9c 44 25 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffc03ab1898 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f526a4d4257
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc03ab1950
RBP: 00007ffc03ab1950 R08: 00007ffc03ab2950 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc03ab29e0
R13: 00007f526a56945c R14: 000000000001391d R15: 00007ffc03ab2a20
</TASK>
Kernel Offset: disabled
Rebooting in 86400 seconds..
---
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