Code: a2 c7 05 7c 96 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:00007ffe478540a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f4ac1150f17 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe47854160 RBP: 00007ffe47854160 R08: 00007ffe47855160 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe478551f0 R13: 00007f4ac11b971f R14: 000000000000657e R15: 00007ffe47855230 ---[ end trace 038882178fa5b2dd ]--- ================================================================== 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/asm-generic/atomic-instrumented.h:250 [inline] BUG: KASAN: null-ptr-deref in ihold+0x20/0x60 fs/inode.c:423 Write of size 4 at addr 0000000000000170 by task syz-executor/353 CPU: 1 PID: 353 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:77 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118 __kasan_report mm/kasan/report.c:439 [inline] kasan_report+0xd8/0x130 mm/kasan/report.c:452 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/asm-generic/atomic-instrumented.h:250 [inline] ihold+0x20/0x60 fs/inode.c:423 d_delete_notify include/linux/fsnotify.h:264 [inline] vfs_rmdir+0x247/0x3e0 fs/namei.c:3873 incfs_kill_sb+0xfe/0x210 fs/incfs/vfs.c:1973 deactivate_locked_super+0xa0/0x100 fs/super.c:335 deactivate_super+0xaf/0xe0 fs/super.c:366 cleanup_mnt+0x45b/0x510 fs/namespace.c:1123 __cleanup_mnt+0x19/0x20 fs/namespace.c:1130 task_work_run+0x127/0x190 kernel/task_work.c:189 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop+0xcb/0xe0 kernel/entry/common.c:172 exit_to_user_mode_prepare+0x76/0xa0 kernel/entry/common.c:199 syscall_exit_to_user_mode+0x1d/0x40 kernel/entry/common.c:274 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f4ac1150f17 Code: a2 c7 05 7c 96 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:00007ffe478540a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f4ac1150f17 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe47854160 RBP: 00007ffe47854160 R08: 00007ffe47855160 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe478551f0 R13: 00007f4ac11b971f R14: 000000000000657e R15: 00007ffe47855230 ================================================================== BUG: kernel NULL pointer dereference, address: 0000000000000170 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 10fd51067 P4D 10fd51067 PUD 0 Oops: 0002 [#1] PREEMPT SMP KASAN CPU: 1 PID: 353 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-arch-fallback.h:286 [inline] RIP: 0010:atomic_inc_return include/asm-generic/atomic-instrumented.h:251 [inline] RIP: 0010:ihold+0x26/0x60 fs/inode.c:423 Code: 00 00 00 00 55 48 89 e5 41 56 53 48 89 fb e8 f1 69 b7 ff 48 8d bb 70 01 00 00 be 04 00 00 00 e8 40 e8 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 71 RSP: 0018:ffffc90000c77d10 EFLAGS: 00010246 RAX: ffff88810c380000 RBX: 0000000000000000 RCX: 0000000000000286 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00000000ffffffff RBP: ffffc90000c77d20 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffffbfff0dcf448 R12: 1ffff11021a67228 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000 FS: 0000555558823500(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000170 CR3: 000000010ecaa000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: d_delete_notify include/linux/fsnotify.h:264 [inline] vfs_rmdir+0x247/0x3e0 fs/namei.c:3873 incfs_kill_sb+0xfe/0x210 fs/incfs/vfs.c:1973 deactivate_locked_super+0xa0/0x100 fs/super.c:335 deactivate_super+0xaf/0xe0 fs/super.c:366 cleanup_mnt+0x45b/0x510 fs/namespace.c:1123 __cleanup_mnt+0x19/0x20 fs/namespace.c:1130 task_work_run+0x127/0x190 kernel/task_work.c:189 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop+0xcb/0xe0 kernel/entry/common.c:172 exit_to_user_mode_prepare+0x76/0xa0 kernel/entry/common.c:199 syscall_exit_to_user_mode+0x1d/0x40 kernel/entry/common.c:274 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f4ac1150f17 Code: a2 c7 05 7c 96 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:00007ffe478540a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f4ac1150f17 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe47854160 RBP: 00007ffe47854160 R08: 00007ffe47855160 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe478551f0 R13: 00007f4ac11b971f R14: 000000000000657e R15: 00007ffe47855230 Modules linked in: CR2: 0000000000000170 ---[ end trace 038882178fa5b2de ]--- RIP: 0010:arch_atomic_add_return arch/x86/include/asm/atomic.h:165 [inline] RIP: 0010:arch_atomic_inc_return include/linux/atomic-arch-fallback.h:286 [inline] RIP: 0010:atomic_inc_return include/asm-generic/atomic-instrumented.h:251 [inline] RIP: 0010:ihold+0x26/0x60 fs/inode.c:423 Code: 00 00 00 00 55 48 89 e5 41 56 53 48 89 fb e8 f1 69 b7 ff 48 8d bb 70 01 00 00 be 04 00 00 00 e8 40 e8 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 71 RSP: 0018:ffffc90000c77d10 EFLAGS: 00010246 RAX: ffff88810c380000 RBX: 0000000000000000 RCX: 0000000000000286 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00000000ffffffff RBP: ffffc90000c77d20 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffffbfff0dcf448 R12: 1ffff11021a67228 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000 FS: 0000555558823500(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000170 CR3: 000000010ecaa000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: a2 c7 05 7c 96 24 00 movabs %al,0x24967c05c7 7: 00 00 9: 00 00 add %al,(%rax) b: eb 96 jmp 0xffffffa3 d: e8 e1 12 00 00 call 0x12f3 12: 90 nop 13: 31 f6 xor %esi,%esi 15: e9 09 00 00 00 jmp 0x23 1a: 66 0f 1f 84 00 00 00 nopw 0x0(%rax,%rax,1) 21: 00 00 23: b8 a6 00 00 00 mov $0xa6,%eax 28: 0f 05 syscall * 2a: 48 3d 00 f0 ff ff cmp $0xfffffffffffff000,%rax <-- trapping instruction 30: 77 01 ja 0x33 32: c3 ret 33: 48 c7 c2 e8 ff ff ff mov $0xffffffffffffffe8,%rdx 3a: f7 d8 neg %eax 3c: 64 89 02 mov %eax,%fs:(%rdx) 3f: b8 .byte 0xb8