Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 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 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffe4d4c2468 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f294ea56a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe4d4c2520
RBP: 00007ffe4d4c2520 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe4d4c35b0
R13: 00007f294ead9d7d R14: 0000000000006964 R15: 00007ffe4d4c35f0
---[ end trace b7d6dc927ce9078c ]---
==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
BUG: KASAN: null-ptr-deref in atomic_inc_return include/linux/atomic/atomic-instrumented.h:188 [inline]
BUG: KASAN: null-ptr-deref in ihold+0x20/0x60 fs/inode.c:454
Write of size 4 at addr 0000000000000170 by task syz-executor/360
CPU: 1 PID: 360 Comm: syz-executor Tainted: G W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
__dump_stack+0x21/0x30 lib/dump_stack.c:88
dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106
__kasan_report mm/kasan/report.c:431 [inline]
kasan_report+0xe7/0x140 mm/kasan/report.c:444
check_region_inline mm/kasan/generic.c:-1 [inline]
kasan_check_range+0x280/0x290 mm/kasan/generic.c:189
__kasan_check_write+0x14/0x20 mm/kasan/shadow.c:37
instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
atomic_inc_return include/linux/atomic/atomic-instrumented.h:188 [inline]
ihold+0x20/0x60 fs/inode.c:454
d_delete_notify include/linux/fsnotify.h:275 [inline]
vfs_rmdir+0x1f0/0x460 fs/namei.c:4170
incfs_kill_sb+0x105/0x220 fs/incfs/vfs.c:1989
deactivate_locked_super+0xa0/0x100 fs/super.c:335
deactivate_super+0xaf/0xe0 fs/super.c:366
cleanup_mnt+0x446/0x500 fs/namespace.c:1148
__cleanup_mnt+0x19/0x20 fs/namespace.c:1155
task_work_run+0x127/0x190 kernel/task_work.c:188
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop+0xd0/0xe0 kernel/entry/common.c:181
exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:307
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f294ea56a77
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 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 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffe4d4c2468 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f294ea56a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe4d4c2520
RBP: 00007ffe4d4c2520 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe4d4c35b0
R13: 00007f294ead9d7d R14: 0000000000006964 R15: 00007ffe4d4c35f0
==================================================================
BUG: kernel NULL pointer dereference, address: 0000000000000170
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 11fea2067 P4D 11fea2067 PUD 0
Oops: 0002 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 360 Comm: syz-executor Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:arch_atomic_add_return arch/x86/include/asm/atomic.h:165 [inline]
RIP: 0010:arch_atomic_inc_return include/linux/atomic/atomic-arch-fallback.h:370 [inline]
RIP: 0010:atomic_inc_return include/linux/atomic/atomic-instrumented.h:189 [inline]
RIP: 0010:ihold+0x26/0x60 fs/inode.c:454
Code: 00 00 00 00 55 48 89 e5 41 56 53 48 89 fb e8 31 a8 b3 ff 48 8d bb 70 01 00 00 be 04 00 00 00 e8 d0 2c f2 ff 41 be 01 00 00 00 44 0f c1 b3 70 01 00 00 41 ff c6 bf 02 00 00 00 44 89 f6 e8 b1
RSP: 0018:ffffc90002bf7ce8 EFLAGS: 00010246
RAX: ffff88810d5b1300 RBX: 0000000000000000 RCX: ffff88810d5b13c0
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00000000ffffffff
RBP: ffffc90002bf7cf8 R08: 0000000000000004 R09: 0000000000000003
R10: fffffbfff0e1824c R11: 1ffffffff0e1824c R12: 1ffff11021a20c8e
R13: dffffc0000000000 R14: 0000000000000001 R15: 0000000000000000
FS: 0000555594586500(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000170 CR3: 000000012221c000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
d_delete_notify include/linux/fsnotify.h:275 [inline]
vfs_rmdir+0x1f0/0x460 fs/namei.c:4170
incfs_kill_sb+0x105/0x220 fs/incfs/vfs.c:1989
deactivate_locked_super+0xa0/0x100 fs/super.c:335
deactivate_super+0xaf/0xe0 fs/super.c:366
cleanup_mnt+0x446/0x500 fs/namespace.c:1148
__cleanup_mnt+0x19/0x20 fs/namespace.c:1155
task_work_run+0x127/0x190 kernel/task_work.c:188
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop+0xd0/0xe0 kernel/entry/common.c:181
exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:307
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f294ea56a77
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 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 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffe4d4c2468 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f294ea56a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe4d4c2520
RBP: 00007ffe4d4c2520 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe4d4c35b0
R13: 00007f294ead9d7d R14: 0000000000006964 R15: 00007ffe4d4c35f0
Modules linked in:
CR2: 0000000000000170
---[ end trace b7d6dc927ce9078d ]---
RIP: 0010:arch_atomic_add_return arch/x86/include/asm/atomic.h:165 [inline]
RIP: 0010:arch_atomic_inc_return include/linux/atomic/atomic-arch-fallback.h:370 [inline]
RIP: 0010:atomic_inc_return include/linux/atomic/atomic-instrumented.h:189 [inline]
RIP: 0010:ihold+0x26/0x60 fs/inode.c:454
Code: 00 00 00 00 55 48 89 e5 41 56 53 48 89 fb e8 31 a8 b3 ff 48 8d bb 70 01 00 00 be 04 00 00 00 e8 d0 2c f2 ff 41 be 01 00 00 00 44 0f c1 b3 70 01 00 00 41 ff c6 bf 02 00 00 00 44 89 f6 e8 b1
RSP: 0018:ffffc90002bf7ce8 EFLAGS: 00010246
RAX: ffff88810d5b1300 RBX: 0000000000000000 RCX: ffff88810d5b13c0
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00000000ffffffff
RBP: ffffc90002bf7cf8 R08: 0000000000000004 R09: 0000000000000003
R10: fffffbfff0e1824c R11: 1ffffffff0e1824c R12: 1ffff11021a20c8e
R13: dffffc0000000000 R14: 0000000000000001 R15: 0000000000000000
FS: 0000555594586500(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000170 CR3: 000000012221c000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess), 3 bytes skipped:
0: ff f7 push %rdi
2: d8 64 89 01 fsubs 0x1(%rcx,%rcx,4)
6: 48 83 c8 ff or $0xffffffffffffffff,%rax
a: c3 ret
b: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
10: 31 f6 xor %esi,%esi
12: e9 09 00 00 00 jmp 0x20
17: 66 0f 1f 84 00 00 00 nopw 0x0(%rax,%rax,1)
1e: 00 00
20: b8 a6 00 00 00 mov $0xa6,%eax
25: 0f 05 syscall
* 27: 48 3d 00 f0 ff ff cmp $0xfffffffffffff000,%rax <-- trapping instruction
2d: 77 01 ja 0x30
2f: c3 ret
30: 48 c7 c2 a8 ff ff ff mov $0xffffffffffffffa8,%rdx
37: f7 d8 neg %eax
39: 64 89 02 mov %eax,%fs:(%rdx)
3c: b8 .byte 0xb8