R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fe440dbefac R14: 00007fe440dbefa0 R15: 00007fe440dbefa0
---[ end trace 8d6aebf1827028cf ]---
==================================================================
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.2.17/372
CPU: 1 PID: 372 Comm: syz.2.17 Tainted: G W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
__dump_stack+0x21/0x30 lib/dump_stack.c:88
dump_stack_lvl+0x110/0x170 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+0x249/0x2a0 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+0x45b/0x510 fs/namespace.c:1148
__cleanup_mnt+0x19/0x20 fs/namespace.c:1155
task_work_run+0x127/0x190 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0xb35/0x2890 kernel/exit.c:890
do_group_exit+0x141/0x310 kernel/exit.c:1004
get_signal+0x66a/0x1480 kernel/signal.c:2907
arch_do_signal_or_restart+0xdf/0x11c0 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0xa7/0xe0 kernel/entry/common.c:178
exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:214
irqentry_exit_to_user_mode+0x9/0x10 kernel/entry/common.c:320
irqentry_exit+0x12/0x40 kernel/entry/common.c:411
exc_page_fault+0x5e/0xb0 arch/x86/mm/fault.c:1563
asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0033:0x7fe4409fbb20
Code: Unable to access opcode bytes at RIP 0x7fe4409fbaf6.
RSP: 002b:00007ffc76254b78 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007fe440b45e59
RDX: 00007ffc76254b80 RSI: 00007ffc76254cb0 RDI: 000000000000000b
RBP: 00007fe440bdbd6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fe440dbefac R14: 00007fe440dbefa0 R15: 00007fe440dbefa0
==================================================================
BUG: kernel NULL pointer dereference, address: 0000000000000170
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 0 P4D 0
Oops: 0002 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 372 Comm: syz.2.17 Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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 b1 c3 b2 ff 48 8d bb 70 01 00 00 be 04 00 00 00 e8 90 fb f1 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 31
RSP: 0018:ffffc90000ac7828 EFLAGS: 00010246
RAX: ffff888110534f00 RBX: 0000000000000000 RCX: ffff888110534f00
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00000000ffffffff
RBP: ffffc90000ac7838 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff0e18e4c R12: 1ffff1102125ec4a
R13: dffffc0000000000 R14: 0000000000000001 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000170 CR3: 000000010c8ce000 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+0x45b/0x510 fs/namespace.c:1148
__cleanup_mnt+0x19/0x20 fs/namespace.c:1155
task_work_run+0x127/0x190 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0xb35/0x2890 kernel/exit.c:890
do_group_exit+0x141/0x310 kernel/exit.c:1004
get_signal+0x66a/0x1480 kernel/signal.c:2907
arch_do_signal_or_restart+0xdf/0x11c0 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0xa7/0xe0 kernel/entry/common.c:178
exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:214
irqentry_exit_to_user_mode+0x9/0x10 kernel/entry/common.c:320
irqentry_exit+0x12/0x40 kernel/entry/common.c:411
exc_page_fault+0x5e/0xb0 arch/x86/mm/fault.c:1563
asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0033:0x7fe4409fbb20
Code: Unable to access opcode bytes at RIP 0x7fe4409fbaf6.
RSP: 002b:00007ffc76254b78 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007fe440b45e59
RDX: 00007ffc76254b80 RSI: 00007ffc76254cb0 RDI: 000000000000000b
RBP: 00007fe440bdbd6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fe440dbefac R14: 00007fe440dbefa0 R15: 00007fe440dbefa0
Modules linked in:
CR2: 0000000000000170
---[ end trace 8d6aebf1827028d0 ]---
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 b1 c3 b2 ff 48 8d bb 70 01 00 00 be 04 00 00 00 e8 90 fb f1 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 31
RSP: 0018:ffffc90000ac7828 EFLAGS: 00010246
RAX: ffff888110534f00 RBX: 0000000000000000 RCX: ffff888110534f00
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00000000ffffffff
RBP: ffffc90000ac7838 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff0e18e4c R12: 1ffff1102125ec4a
R13: dffffc0000000000 R14: 0000000000000001 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000170 CR3: 000000010c8ce000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 00 00 add %al,(%rax)
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 b1 c3 b2 ff call 0xffb2c3c4
13: 48 8d bb 70 01 00 00 lea 0x170(%rbx),%rdi
1a: be 04 00 00 00 mov $0x4,%esi
1f: e8 90 fb f1 ff call 0xfff1fbb4
24: 41 be 01 00 00 00 mov $0x1,%r14d
* 2a: f0 44 0f c1 b3 70 01 lock xadd %r14d,0x170(%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: 31 .byte 0x31