---[ end trace 7a5823459285ec57 ]--- ================================================================== BUG: KASAN: null-ptr-deref in atomic_try_cmpxchg include/asm-generic/atomic-instrumented.h:693 [inline] BUG: KASAN: null-ptr-deref in queued_spin_lock include/asm-generic/qspinlock.h:78 [inline] BUG: KASAN: null-ptr-deref in do_raw_spin_lock include/linux/spinlock.h:181 [inline] BUG: KASAN: null-ptr-deref in __raw_spin_lock include/linux/spinlock_api_smp.h:143 [inline] BUG: KASAN: null-ptr-deref in _raw_spin_lock+0x5f/0x170 kernel/locking/spinlock.c:151 Write of size 4 at addr 0000000000000088 by task syz-executor.0/12656 CPU: 1 PID: 12656 Comm: syz-executor.0 Tainted: G W 5.4.161-syzkaller-00025-g961dd91cc692 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x18e/0x1de lib/dump_stack.c:118 __kasan_report+0x178/0x260 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+0x2a5/0x2e0 mm/kasan/generic.c:191 atomic_try_cmpxchg include/asm-generic/atomic-instrumented.h:693 [inline] queued_spin_lock include/asm-generic/qspinlock.h:78 [inline] do_raw_spin_lock include/linux/spinlock.h:181 [inline] __raw_spin_lock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_lock+0x5f/0x170 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:338 [inline] d_delete+0x46/0x100 fs/dcache.c:2444 vfs_rmdir+0x1c9/0x3e0 fs/namei.c:3971 incfs_kill_sb+0x9b/0xe0 fs/incfs/vfs.c:1885 deactivate_locked_super+0xaf/0x100 fs/super.c:335 deactivate_super+0x168/0x210 fs/super.c:366 cleanup_mnt+0x432/0x4e0 fs/namespace.c:1102 task_work_run+0x186/0x1b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop arch/x86/entry/common.c:163 [inline] prepare_exit_to_usermode+0x2b0/0x310 arch/x86/entry/common.c:194 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f3465106059 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f346427c168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f3465218f60 RCX: 00007f3465106059 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000180 RBP: 00007f346516008d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd3d7d01cf R14: 00007f346427c300 R15: 0000000000022000 ================================================================== BUG: kernel NULL pointer dereference, address: 0000000000000088 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 1ae4fa067 P4D 1ae4fa067 PUD 1e8fc2067 PMD 0 Oops: 0002 [#1] PREEMPT SMP KASAN CPU: 1 PID: 12656 Comm: syz-executor.0 Tainted: G B W 5.4.161-syzkaller-00025-g961dd91cc692 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:arch_atomic_try_cmpxchg arch/x86/include/asm/atomic.h:200 [inline] RIP: 0010:atomic_try_cmpxchg include/asm-generic/atomic-instrumented.h:695 [inline] RIP: 0010:queued_spin_lock include/asm-generic/qspinlock.h:78 [inline] RIP: 0010:do_raw_spin_lock include/linux/spinlock.h:181 [inline] RIP: 0010:__raw_spin_lock include/linux/spinlock_api_smp.h:143 [inline] RIP: 0010:_raw_spin_lock+0x82/0x170 kernel/locking/spinlock.c:151 Code: 00 00 e8 21 6e 69 fd 48 89 df be 04 00 00 00 e8 14 6e 69 fd 42 8a 44 35 00 84 c0 0f 85 a0 00 00 00 8b 44 24 04 b9 01 00 00 00 41 0f b1 0c 24 75 21 65 48 8b 04 25 28 00 00 00 48 3b 44 24 08 RSP: 0018:ffff8881ed3b7d10 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8881ed3b7d14 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff8881ed3b7d14 RBP: 1ffff1103da76fa2 R08: dffffc0000000000 R09: ffffed103da76fa3 R10: ffffed103da76fa3 R11: 0000000000000000 R12: 0000000000000088 R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000200108 FS: 00007f346427c700(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000088 CR3: 00000001e4d75000 CR4: 00000000003406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: spin_lock include/linux/spinlock.h:338 [inline] d_delete+0x46/0x100 fs/dcache.c:2444 vfs_rmdir+0x1c9/0x3e0 fs/namei.c:3971 incfs_kill_sb+0x9b/0xe0 fs/incfs/vfs.c:1885 deactivate_locked_super+0xaf/0x100 fs/super.c:335 deactivate_super+0x168/0x210 fs/super.c:366 cleanup_mnt+0x432/0x4e0 fs/namespace.c:1102 task_work_run+0x186/0x1b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop arch/x86/entry/common.c:163 [inline] prepare_exit_to_usermode+0x2b0/0x310 arch/x86/entry/common.c:194 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f3465106059 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f346427c168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f3465218f60 RCX: 00007f3465106059 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000180 RBP: 00007f346516008d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd3d7d01cf R14: 00007f346427c300 R15: 0000000000022000 Modules linked in: CR2: 0000000000000088 ---[ end trace 7a5823459285ec58 ]--- RIP: 0010:arch_atomic_try_cmpxchg arch/x86/include/asm/atomic.h:200 [inline] RIP: 0010:atomic_try_cmpxchg include/asm-generic/atomic-instrumented.h:695 [inline] RIP: 0010:queued_spin_lock include/asm-generic/qspinlock.h:78 [inline] RIP: 0010:do_raw_spin_lock include/linux/spinlock.h:181 [inline] RIP: 0010:__raw_spin_lock include/linux/spinlock_api_smp.h:143 [inline] RIP: 0010:_raw_spin_lock+0x82/0x170 kernel/locking/spinlock.c:151 Code: 00 00 e8 21 6e 69 fd 48 89 df be 04 00 00 00 e8 14 6e 69 fd 42 8a 44 35 00 84 c0 0f 85 a0 00 00 00 8b 44 24 04 b9 01 00 00 00 41 0f b1 0c 24 75 21 65 48 8b 04 25 28 00 00 00 48 3b 44 24 08 RSP: 0018:ffff8881ed3b7d10 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8881ed3b7d14 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff8881ed3b7d14 RBP: 1ffff1103da76fa2 R08: dffffc0000000000 R09: ffffed103da76fa3 R10: ffffed103da76fa3 R11: 0000000000000000 R12: 0000000000000088 R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000200108 FS: 00007f346427c700(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000088 CR3: 00000001e4d75000 CR4: 00000000003406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: e8 21 6e 69 fd callq 0xfd696e28 7: 48 89 df mov %rbx,%rdi a: be 04 00 00 00 mov $0x4,%esi f: e8 14 6e 69 fd callq 0xfd696e28 14: 42 8a 44 35 00 mov 0x0(%rbp,%r14,1),%al 19: 84 c0 test %al,%al 1b: 0f 85 a0 00 00 00 jne 0xc1 21: 8b 44 24 04 mov 0x4(%rsp),%eax 25: b9 01 00 00 00 mov $0x1,%ecx * 2a: f0 41 0f b1 0c 24 lock cmpxchg %ecx,(%r12) <-- trapping instruction 30: 75 21 jne 0x53 32: 65 48 8b 04 25 28 00 mov %gs:0x28,%rax 39: 00 00 3b: 48 3b 44 24 08 cmp 0x8(%rsp),%rax