------------[ cut here ]------------
WARNING: CPU: 1 PID: 292 at fs/inode.c:340 drop_nlink+0xce/0x110 fs/inode.c:340
Modules linked in:
CPU: 1 UID: 0 PID: 292 Comm: syz-executor Not tainted syzkaller #0 4cdc09a83674403ae09eb79c4caea2b8730b48e4
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:drop_nlink+0xce/0x110 fs/inode.c:340
Code: 04 00 00 be 08 00 00 00 e8 df 15 ee ff f0 48 ff 83 b8 04 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc e8 f2 e5 95 ff <0f> 0b eb 81 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 59 ff ff ff 4c
RSP: 0018:ffffc9000b6bfc60 EFLAGS: 00010293
RAX: ffffffff81f1c2ae RBX: ffff88810cb6bbf0 RCX: ffff8881234f3900
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000b6bfc88 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520016d7f7c R12: dffffc0000000000
R13: 1ffff1102196d787 R14: ffff88810cb6bc38 R15: 0000000000000000
FS: 000055557412f500(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555574152948 CR3: 0000000123246000 CR4: 00000000003526b0
Call Trace:
<TASK>
incfs_kill_sb+0x109/0x230 fs/incfs/vfs.c:1968
deactivate_locked_super+0xd5/0x2a0 fs/super.c:478
deactivate_super+0xb8/0xe0 fs/super.c:511
cleanup_mnt+0x406/0x4a0 fs/namespace.c:1380
resume_user_mode_work+0x35/0x50 include/linux/resume_user_mode.h:50
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x63/0xb0 kernel/entry/common.c:218
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fad4ab9d9d7
Code: a2 c7 05 1c fd 24 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:00007ffffec5c928 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fad4ab9d9d7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffffec5c9e0
RBP: 00007ffffec5c9e0 R08: 00007ffffec5d9e0 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffffec5da70
R13: 00007fad4ac32050 R14: 000000000000bc2b R15: 00007ffffec5dab0
</TASK>
---[ end trace 0000000000000000 ]---
==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: null-ptr-deref in atomic_inc_return include/linux/atomic/atomic-instrumented.h:453 [inline]
BUG: KASAN: null-ptr-deref in ihold+0x24/0x70 fs/inode.c:452
Write of size 4 at addr 0000000000000168 by task syz-executor/292
CPU: 1 UID: 0 PID: 292 Comm: syz-executor Tainted: G W syzkaller #0 4cdc09a83674403ae09eb79c4caea2b8730b48e4
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
<TASK>
__dump_stack+0x21/0x30 lib/dump_stack.c:94
dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120
print_report+0x3d/0x70 mm/kasan/report.c:484
kasan_report+0x162/0x1a0 mm/kasan/report.c:594
check_region_inline mm/kasan/generic.c:-1 [inline]
kasan_check_range+0x25a/0x2b0 mm/kasan/generic.c:189
__kasan_check_write+0x18/0x20 mm/kasan/shadow.c:37
instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
atomic_inc_return include/linux/atomic/atomic-instrumented.h:453 [inline]
ihold+0x24/0x70 fs/inode.c:452
d_delete_notify include/linux/fsnotify.h:357 [inline]
vfs_rmdir+0x26a/0x560 fs/namei.c:4361
incfs_kill_sb+0x109/0x230 fs/incfs/vfs.c:1968
deactivate_locked_super+0xd5/0x2a0 fs/super.c:478
deactivate_super+0xb8/0xe0 fs/super.c:511
cleanup_mnt+0x406/0x4a0 fs/namespace.c:1380
__cleanup_mnt+0x1d/0x40 fs/namespace.c:1387
task_work_run+0x1e8/0x260 kernel/task_work.c:246
resume_user_mode_work+0x35/0x50 include/linux/resume_user_mode.h:50
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x63/0xb0 kernel/entry/common.c:218
do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fad4ab9d9d7
Code: a2 c7 05 1c fd 24 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:00007ffffec5c928 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fad4ab9d9d7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffffec5c9e0
RBP: 00007ffffec5c9e0 R08: 00007ffffec5d9e0 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffffec5da70
R13: 00007fad4ac32050 R14: 000000000000bc2b R15: 00007ffffec5dab0
</TASK>
==================================================================
BUG: kernel NULL pointer dereference, address: 0000000000000168
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 800000010bfd7067 P4D 800000010bfd7067 PUD 0
Oops: Oops: 0002 [#1] PREEMPT SMP KASAN PTI
CPU: 1 UID: 0 PID: 292 Comm: syz-executor Tainted: G B W syzkaller #0 4cdc09a83674403ae09eb79c4caea2b8730b48e4
Tainted: [B]=BAD_PAGE, [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:arch_atomic_add_return arch/x86/include/asm/atomic.h:85 [inline]
RIP: 0010:raw_atomic_add_return include/linux/atomic/atomic-arch-fallback.h:564 [inline]
RIP: 0010:raw_atomic_inc_return include/linux/atomic/atomic-arch-fallback.h:1020 [inline]
RIP: 0010:atomic_inc_return include/linux/atomic/atomic-instrumented.h:454 [inline]
RIP: 0010:ihold+0x2a/0x70 fs/inode.c:452
Code: f3 0f 1e fa 55 48 89 e5 41 56 53 48 89 fb e8 dd dc 95 ff 48 8d bb 68 01 00 00 be 04 00 00 00 e8 9c 0c ee ff 41 be 01 00 00 00 <f0> 44 0f c1 b3 68 01 00 00 41 ff c6 bf 02 00 00 00 44 89 f6 e8 ed
RSP: 0018:ffffc9000b6bfca0 EFLAGS: 00010246
RAX: ffff8881234f3900 RBX: 0000000000000000 RCX: ffff8881234f3900
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000b6bfcb0 R08: ffffffff88b97947 R09: 1ffffffff1172f28
R10: dffffc0000000000 R11: fffffbfff1172f29 R12: ffff88810cb6bbfc
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
FS: 000055557412f500(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000168 CR3: 0000000123246000 CR4: 00000000003526b0
Call Trace:
<TASK>
d_delete_notify include/linux/fsnotify.h:357 [inline]
vfs_rmdir+0x26a/0x560 fs/namei.c:4361
incfs_kill_sb+0x109/0x230 fs/incfs/vfs.c:1968
deactivate_locked_super+0xd5/0x2a0 fs/super.c:478
deactivate_super+0xb8/0xe0 fs/super.c:511
cleanup_mnt+0x406/0x4a0 fs/namespace.c:1380
__cleanup_mnt+0x1d/0x40 fs/namespace.c:1387
task_work_run+0x1e8/0x260 kernel/task_work.c:246
resume_user_mode_work+0x35/0x50 include/linux/resume_user_mode.h:50
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x63/0xb0 kernel/entry/common.c:218
do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fad4ab9d9d7
Code: a2 c7 05 1c fd 24 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:00007ffffec5c928 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fad4ab9d9d7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffffec5c9e0
RBP: 00007ffffec5c9e0 R08: 00007ffffec5d9e0 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffffec5da70
R13: 00007fad4ac32050 R14: 000000000000bc2b R15: 00007ffffec5dab0
</TASK>
Modules linked in:
CR2: 0000000000000168
---[ end trace 0000000000000000 ]---
RIP: 0010:arch_atomic_add_return arch/x86/include/asm/atomic.h:85 [inline]
RIP: 0010:raw_atomic_add_return include/linux/atomic/atomic-arch-fallback.h:564 [inline]
RIP: 0010:raw_atomic_inc_return include/linux/atomic/atomic-arch-fallback.h:1020 [inline]
RIP: 0010:atomic_inc_return include/linux/atomic/atomic-instrumented.h:454 [inline]
RIP: 0010:ihold+0x2a/0x70 fs/inode.c:452
Code: f3 0f 1e fa 55 48 89 e5 41 56 53 48 89 fb e8 dd dc 95 ff 48 8d bb 68 01 00 00 be 04 00 00 00 e8 9c 0c ee ff 41 be 01 00 00 00 <f0> 44 0f c1 b3 68 01 00 00 41 ff c6 bf 02 00 00 00 44 89 f6 e8 ed
RSP: 0018:ffffc9000b6bfca0 EFLAGS: 00010246
RAX: ffff8881234f3900 RBX: 0000000000000000 RCX: ffff8881234f3900
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000b6bfcb0 R08: ffffffff88b97947 R09: 1ffffffff1172f28
R10: dffffc0000000000 R11: fffffbfff1172f29 R12: ffff88810cb6bbfc
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
FS: 000055557412f500(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000168 CR3: 0000000123246000 CR4: 00000000003526b0
----------------
Code disassembly (best guess):
0: f3 0f 1e fa endbr64
4: 55 push %rbp
5: 48 89 e5 mov %rsp,%rbp
8: 41 56 push %r14
a: 53 push %rbx
b: 48 89 fb mov %rdi,%rbx
e: e8 dd dc 95 ff call 0xff95dcf0
13: 48 8d bb 68 01 00 00 lea 0x168(%rbx),%rdi
1a: be 04 00 00 00 mov $0x4,%esi
1f: e8 9c 0c ee ff call 0xffee0cc0
24: 41 be 01 00 00 00 mov $0x1,%r14d
* 2a: f0 44 0f c1 b3 68 01 lock xadd %r14d,0x168(%rbx) <-- trapping instruction
31: 00 00
33: 41 ff c6 inc %r14d
36: bf 02 00 00 00 mov $0x2,%edi
3b: 44 89 f6 mov %r14d,%esi
3e: e8 .byte 0xe8
3f: ed in (%dx),%eax