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:00007fff35fb8b68 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f47d9d90a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff35fb8c20
RBP: 00007fff35fb8c20 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000206 R12: 00007fff35fb9cb0
R13: 00007f47d9e13d7d R14: 0000000000006601 R15: 00007fff35fb9cf0
---[ end trace 0000000000000000 ]---
==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
BUG: KASAN: null-ptr-deref in atomic_inc_return include/linux/atomic/atomic-instrumented.h:198 [inline]
BUG: KASAN: null-ptr-deref in ihold+0x20/0x60 fs/inode.c:455
Write of size 4 at addr 0000000000000170 by task syz-executor/362
CPU: 0 PID: 362 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+0x21/0x24 lib/dump_stack.c:88
dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106
print_report+0x3d/0x60 mm/kasan/report.c:423
kasan_report+0x122/0x150 mm/kasan/report.c:524
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:102 [inline]
atomic_inc_return include/linux/atomic/atomic-instrumented.h:198 [inline]
ihold+0x20/0x60 fs/inode.c:455
d_delete_notify include/linux/fsnotify.h:289 [inline]
vfs_rmdir+0x25f/0x500 fs/namei.c:4211
incfs_kill_sb+0x105/0x220 fs/incfs/vfs.c:1995
deactivate_locked_super+0xb5/0x120 fs/super.c:334
deactivate_super+0xaf/0xe0 fs/super.c:365
cleanup_mnt+0x45f/0x4e0 fs/namespace.c:1191
__cleanup_mnt+0x19/0x20 fs/namespace.c:1198
task_work_run+0x1db/0x240 kernel/task_work.c:203
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0x9b/0xb0 kernel/entry/common.c:177
exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f47d9d90a77
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:00007fff35fb8b68 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f47d9d90a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff35fb8c20
RBP: 00007fff35fb8c20 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000206 R12: 00007fff35fb9cb0
R13: 00007f47d9e13d7d R14: 0000000000006601 R15: 00007fff35fb9cf0
==================================================================
BUG: kernel NULL pointer dereference, address: 0000000000000170
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 10d342067 P4D 10d342067 PUD 0
Oops: 0002 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 362 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:440 [inline]
RIP: 0010:atomic_inc_return include/linux/atomic/atomic-instrumented.h:199 [inline]
RIP: 0010:ihold+0x26/0x60 fs/inode.c:455
Code: 33 36 7c df 55 48 89 e5 41 56 53 48 89 fb e8 11 62 ac ff 48 8d bb 70 01 00 00 be 04 00 00 00 e8 30 de f0 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 01
RSP: 0018:ffffc90000a27c78 EFLAGS: 00010246
RAX: ffff888112dd6500 RBX: 0000000000000000 RCX: ffff888112dd6540
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000a27c88 R08: dffffc0000000000 R09: fffffbfff0f2d8fd
R10: fffffbfff0f2d8fd R11: 1ffffffff0f2d8fc R12: ffff888112f6408c
R13: dffffc0000000000 R14: 0000000000000001 R15: 0000000000000000
FS: 0000555578b9b500(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000170 CR3: 000000012d92a000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
d_delete_notify include/linux/fsnotify.h:289 [inline]
vfs_rmdir+0x25f/0x500 fs/namei.c:4211
incfs_kill_sb+0x105/0x220 fs/incfs/vfs.c:1995
deactivate_locked_super+0xb5/0x120 fs/super.c:334
deactivate_super+0xaf/0xe0 fs/super.c:365
cleanup_mnt+0x45f/0x4e0 fs/namespace.c:1191
__cleanup_mnt+0x19/0x20 fs/namespace.c:1198
task_work_run+0x1db/0x240 kernel/task_work.c:203
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0x9b/0xb0 kernel/entry/common.c:177
exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f47d9d90a77
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:00007fff35fb8b68 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f47d9d90a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff35fb8c20
RBP: 00007fff35fb8c20 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000206 R12: 00007fff35fb9cb0
R13: 00007f47d9e13d7d R14: 0000000000006601 R15: 00007fff35fb9cf0
Modules linked in:
CR2: 0000000000000170
---[ end trace 0000000000000000 ]---
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:440 [inline]
RIP: 0010:atomic_inc_return include/linux/atomic/atomic-instrumented.h:199 [inline]
RIP: 0010:ihold+0x26/0x60 fs/inode.c:455
Code: 33 36 7c df 55 48 89 e5 41 56 53 48 89 fb e8 11 62 ac ff 48 8d bb 70 01 00 00 be 04 00 00 00 e8 30 de f0 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 01
RSP: 0018:ffffc90000a27c78 EFLAGS: 00010246
RAX: ffff888112dd6500 RBX: 0000000000000000 RCX: ffff888112dd6540
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000a27c88 R08: dffffc0000000000 R09: fffffbfff0f2d8fd
R10: fffffbfff0f2d8fd R11: 1ffffffff0f2d8fc R12: ffff888112f6408c
R13: dffffc0000000000 R14: 0000000000000001 R15: 0000000000000000
FS: 0000555578b9b500(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000170 CR3: 000000012d92a000 CR4: 00000000003506b0
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