RBP: 00007ffdf5dc5800 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffdf5dc6890 R13: 00007f71d6bf689d R14: 000000000003b0ec R15: 00007ffdf5dc68d0 ---[ end trace 340fe48b4948ff61 ]--- ================================================================== BUG: KASAN: null-ptr-deref in atomic_add_return include/asm-generic/atomic-instrumented.h:71 [inline] BUG: KASAN: null-ptr-deref in atomic_inc_return include/linux/atomic-fallback.h:284 [inline] BUG: KASAN: null-ptr-deref in ihold+0x20/0x60 fs/inode.c:421 Write of size 4 at addr 0000000000000160 by task syz-executor/5894 CPU: 0 PID: 5894 Comm: syz-executor Tainted: G W 5.4.292-syzkaller-00021-gcd8e74fa0fa3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack+0x1e/0x20 lib/dump_stack.c:77 dump_stack+0x15b/0x1b8 lib/dump_stack.c:118 __kasan_report+0xe4/0x120 mm/kasan/report.c:520 kasan_report+0x30/0x60 mm/kasan/common.c:653 check_memory_region_inline mm/kasan/generic.c:141 [inline] check_memory_region+0x274/0x280 mm/kasan/generic.c:191 __kasan_check_write+0x14/0x20 mm/kasan/common.c:99 atomic_add_return include/asm-generic/atomic-instrumented.h:71 [inline] atomic_inc_return include/linux/atomic-fallback.h:284 [inline] ihold+0x20/0x60 fs/inode.c:421 d_delete_notify include/linux/fsnotify.h:227 [inline] vfs_rmdir+0x247/0x3e0 fs/namei.c:4040 incfs_kill_sb+0xfe/0x210 fs/incfs/vfs.c:1944 deactivate_locked_super+0xa0/0x100 fs/super.c:335 deactivate_super+0x14f/0x1d0 fs/super.c:366 cleanup_mnt+0x446/0x500 fs/namespace.c:1102 __cleanup_mnt+0x19/0x20 fs/namespace.c:1109 task_work_run+0x146/0x170 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x195/0x1b0 arch/x86/entry/common.c:163 prepare_exit_to_usermode+0x18e/0x1f0 arch/x86/entry/common.c:194 syscall_return_slowpath arch/x86/entry/common.c:274 [inline] do_syscall_64+0x13e/0x170 arch/x86/entry/common.c:300 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7f71d6b75c97 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:00007ffdf5dc5748 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f71d6b75c97 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdf5dc5800 RBP: 00007ffdf5dc5800 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffdf5dc6890 R13: 00007f71d6bf689d R14: 000000000003b0ec R15: 00007ffdf5dc68d0 ================================================================== BUG: kernel NULL pointer dereference, address: 0000000000000160 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 1deddb067 P4D 1deddb067 PUD 0 Oops: 0002 [#1] PREEMPT SMP KASAN CPU: 1 PID: 5894 Comm: syz-executor Tainted: G B W 5.4.292-syzkaller-00021-gcd8e74fa0fa3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:arch_atomic_add_return arch/x86/include/asm/atomic.h:167 [inline] RIP: 0010:atomic_add_return include/asm-generic/atomic-instrumented.h:72 [inline] RIP: 0010:atomic_inc_return include/linux/atomic-fallback.h:284 [inline] RIP: 0010:ihold+0x26/0x60 fs/inode.c:421 Code: 00 00 00 00 55 48 89 e5 41 56 53 48 89 fb e8 61 c8 c5 ff 48 8d bb 60 01 00 00 be 04 00 00 00 e8 a0 9c f3 ff 41 be 01 00 00 00 <f0> 44 0f c1 b3 60 01 00 00 41 ff c6 bf 02 00 00 00 44 89 f6 e8 81 RSP: 0018:ffff8881c40dfc40 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff8881e1a1af40 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00000000ffffffff RBP: ffff8881c40dfc50 R08: 0000000000000004 R09: 0000000000000003 R10: fffffbfff0ca7a5c R11: 1ffffffff0ca7a5c R12: 1ffff1103996f37c R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000 FS: 000055558b50f500(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000160 CR3: 00000001dfa3c000 CR4: 00000000003406a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: d_delete_notify include/linux/fsnotify.h:227 [inline] vfs_rmdir+0x247/0x3e0 fs/namei.c:4040 incfs_kill_sb+0xfe/0x210 fs/incfs/vfs.c:1944 deactivate_locked_super+0xa0/0x100 fs/super.c:335 deactivate_super+0x14f/0x1d0 fs/super.c:366 cleanup_mnt+0x446/0x500 fs/namespace.c:1102 __cleanup_mnt+0x19/0x20 fs/namespace.c:1109 task_work_run+0x146/0x170 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x195/0x1b0 arch/x86/entry/common.c:163 prepare_exit_to_usermode+0x18e/0x1f0 arch/x86/entry/common.c:194 syscall_return_slowpath arch/x86/entry/common.c:274 [inline] do_syscall_64+0x13e/0x170 arch/x86/entry/common.c:300 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7f71d6b75c97 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:00007ffdf5dc5748 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f71d6b75c97 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdf5dc5800 RBP: 00007ffdf5dc5800 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffdf5dc6890 R13: 00007f71d6bf689d R14: 000000000003b0ec R15: 00007ffdf5dc68d0 Modules linked in: CR2: 0000000000000160 ---[ end trace 340fe48b4948ff62 ]--- RIP: 0010:arch_atomic_add_return arch/x86/include/asm/atomic.h:167 [inline] RIP: 0010:atomic_add_return include/asm-generic/atomic-instrumented.h:72 [inline] RIP: 0010:atomic_inc_return include/linux/atomic-fallback.h:284 [inline] RIP: 0010:ihold+0x26/0x60 fs/inode.c:421 Code: 00 00 00 00 55 48 89 e5 41 56 53 48 89 fb e8 61 c8 c5 ff 48 8d bb 60 01 00 00 be 04 00 00 00 e8 a0 9c f3 ff 41 be 01 00 00 00 <f0> 44 0f c1 b3 60 01 00 00 41 ff c6 bf 02 00 00 00 44 89 f6 e8 81 RSP: 0018:ffff8881c40dfc40 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff8881e1a1af40 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00000000ffffffff RBP: ffff8881c40dfc50 R08: 0000000000000004 R09: 0000000000000003 R10: fffffbfff0ca7a5c R11: 1ffffffff0ca7a5c R12: 1ffff1103996f37c R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000 FS: 000055558b50f500(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000160 CR3: 00000001dfa3c000 CR4: 00000000003406a0 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 61 c8 c5 ff call 0xffc5c874 13: 48 8d bb 60 01 00 00 lea 0x160(%rbx),%rdi 1a: be 04 00 00 00 mov $0x4,%esi 1f: e8 a0 9c f3 ff call 0xfff39cc4 24: 41 be 01 00 00 00 mov $0x1,%r14d * 2a: f0 44 0f c1 b3 60 01 lock xadd %r14d,0x160(%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: 81 .byte 0x81