================================================================== BUG: KASAN: null-ptr-deref in instrument_atomic_read_write include/linux/instrumented.h:101 [inline] BUG: KASAN: null-ptr-deref in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:111 [inline] BUG: KASAN: null-ptr-deref in __refcount_add include/linux/refcount.h:193 [inline] BUG: KASAN: null-ptr-deref in __refcount_inc include/linux/refcount.h:250 [inline] BUG: KASAN: null-ptr-deref in refcount_inc include/linux/refcount.h:267 [inline] BUG: KASAN: null-ptr-deref in get_task_struct include/linux/sched/task.h:105 [inline] BUG: KASAN: null-ptr-deref in kthread_stop+0x36/0x3c0 kernel/kthread.c:644 Write of size 4 at addr 000000000000001c by task syz-executor780/419 CPU: 0 PID: 419 Comm: syz-executor780 Not tainted 5.15.74-syzkaller-04383-g7f2e600bf63a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106 __kasan_report mm/kasan/report.c:439 [inline] kasan_report+0x19c/0x1f0 mm/kasan/report.c:452 kasan_check_range+0x2aa/0x2e0 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_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:111 [inline] __refcount_add include/linux/refcount.h:193 [inline] __refcount_inc include/linux/refcount.h:250 [inline] refcount_inc include/linux/refcount.h:267 [inline] get_task_struct include/linux/sched/task.h:105 [inline] kthread_stop+0x36/0x3c0 kernel/kthread.c:644 f2fs_stop_discard_thread+0xa1/0xc0 fs/f2fs/segment.c:1761 kill_f2fs_super+0xe0/0x3c0 fs/f2fs/super.c:4525 deactivate_locked_super+0xb0/0x100 fs/super.c:335 deactivate_super+0xa5/0xd0 fs/super.c:366 cleanup_mnt+0x45f/0x510 fs/namespace.c:1143 __cleanup_mnt+0x19/0x20 fs/namespace.c:1150 task_work_run+0x147/0x1b0 kernel/task_work.c:164 ptrace_notify+0x29a/0x340 kernel/signal.c:2382 ptrace_report_syscall include/linux/tracehook.h:66 [inline] tracehook_report_syscall_exit include/linux/tracehook.h:130 [inline] arch_syscall_exit_tracehook include/linux/entry-common.h:297 [inline] syscall_exit_work+0x94/0x150 kernel/entry/common.c:255 syscall_exit_to_user_mode_prepare kernel/entry/common.c:282 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:287 [inline] syscall_exit_to_user_mode+0x6c/0xc0 kernel/entry/common.c:300 do_syscall_64+0x50/0xd0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f58f059ebd7 Code: 07 00 48 83 c4 08 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fffa701fcf8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f58f059ebd7 RDX: 00007fffa701fdb9 RSI: 000000000000000a RDI: 00007fffa701fdb0 RBP: 00007fffa701fdb0 R08: 00000000ffffffff R09: 00007fffa701fb90 R10: 0000555556734653 R11: 0000000000000202 R12: 00007fffa7020e30 R13: 00005555567345f0 R14: 00007fffa701fd20 R15: 0000000000000002 ================================================================== BUG: kernel NULL pointer dereference, address: 000000000000001c #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: 419 Comm: syz-executor780 Tainted: G B 5.15.74-syzkaller-04383-g7f2e600bf63a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 RIP: 0010:atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:112 [inline] RIP: 0010:__refcount_add include/linux/refcount.h:193 [inline] RIP: 0010:__refcount_inc include/linux/refcount.h:250 [inline] RIP: 0010:refcount_inc include/linux/refcount.h:267 [inline] RIP: 0010:get_task_struct include/linux/sched/task.h:105 [inline] RIP: 0010:kthread_stop+0x3b/0x3c0 kernel/kthread.c:644 Code: bd 00 00 00 00 00 fc ff df e8 61 cc 25 00 0f 1f 44 00 00 4d 8d 74 24 28 4c 89 f7 be 04 00 00 00 e8 0a 1b 68 00 bb 01 00 00 00 41 0f c1 5c 24 28 31 ff 89 de e8 a5 d0 25 00 85 db 0f 84 33 01 RSP: 0018:ffffc9000038fb58 EFLAGS: 00010246 RAX: ffff888105f90000 RBX: 0000000000000001 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000292 RDI: 0000000000000001 RBP: ffffc9000038fb80 R08: ffffffff8142fa13 R09: fffffbfff0e4f8f5 R10: fffffbfff0e4f8f5 R11: 1ffffffff0e4f8f4 R12: fffffffffffffff4 R13: dffffc0000000000 R14: 000000000000001c R15: dffffc0000000000 FS: 0000555556733300(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000000001c CR3: 0000000107181000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: f2fs_stop_discard_thread+0xa1/0xc0 fs/f2fs/segment.c:1761 kill_f2fs_super+0xe0/0x3c0 fs/f2fs/super.c:4525 deactivate_locked_super+0xb0/0x100 fs/super.c:335 deactivate_super+0xa5/0xd0 fs/super.c:366 cleanup_mnt+0x45f/0x510 fs/namespace.c:1143 __cleanup_mnt+0x19/0x20 fs/namespace.c:1150 task_work_run+0x147/0x1b0 kernel/task_work.c:164 ptrace_notify+0x29a/0x340 kernel/signal.c:2382 ptrace_report_syscall include/linux/tracehook.h:66 [inline] tracehook_report_syscall_exit include/linux/tracehook.h:130 [inline] arch_syscall_exit_tracehook include/linux/entry-common.h:297 [inline] syscall_exit_work+0x94/0x150 kernel/entry/common.c:255 syscall_exit_to_user_mode_prepare kernel/entry/common.c:282 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:287 [inline] syscall_exit_to_user_mode+0x6c/0xc0 kernel/entry/common.c:300 do_syscall_64+0x50/0xd0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f58f059ebd7 Code: 07 00 48 83 c4 08 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fffa701fcf8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f58f059ebd7 RDX: 00007fffa701fdb9 RSI: 000000000000000a RDI: 00007fffa701fdb0 RBP: 00007fffa701fdb0 R08: 00000000ffffffff R09: 00007fffa701fb90 R10: 0000555556734653 R11: 0000000000000202 R12: 00007fffa7020e30 R13: 00005555567345f0 R14: 00007fffa701fd20 R15: 0000000000000002 Modules linked in: CR2: 000000000000001c ---[ end trace 2726d20e06291262 ]--- RIP: 0010:atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:112 [inline] RIP: 0010:__refcount_add include/linux/refcount.h:193 [inline] RIP: 0010:__refcount_inc include/linux/refcount.h:250 [inline] RIP: 0010:refcount_inc include/linux/refcount.h:267 [inline] RIP: 0010:get_task_struct include/linux/sched/task.h:105 [inline] RIP: 0010:kthread_stop+0x3b/0x3c0 kernel/kthread.c:644 Code: bd 00 00 00 00 00 fc ff df e8 61 cc 25 00 0f 1f 44 00 00 4d 8d 74 24 28 4c 89 f7 be 04 00 00 00 e8 0a 1b 68 00 bb 01 00 00 00 41 0f c1 5c 24 28 31 ff 89 de e8 a5 d0 25 00 85 db 0f 84 33 01 RSP: 0018:ffffc9000038fb58 EFLAGS: 00010246 RAX: ffff888105f90000 RBX: 0000000000000001 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000292 RDI: 0000000000000001 RBP: ffffc9000038fb80 R08: ffffffff8142fa13 R09: fffffbfff0e4f8f5 R10: fffffbfff0e4f8f5 R11: 1ffffffff0e4f8f4 R12: fffffffffffffff4 R13: dffffc0000000000 R14: 000000000000001c R15: dffffc0000000000 FS: 0000555556733300(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000000001c CR3: 0000000107181000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: bd 00 00 00 00 mov $0x0,%ebp 5: 00 fc add %bh,%ah 7: ff (bad) 8: df e8 fucomip %st(0),%st a: 61 (bad) b: cc int3 c: 25 00 0f 1f 44 and $0x441f0f00,%eax 11: 00 00 add %al,(%rax) 13: 4d 8d 74 24 28 lea 0x28(%r12),%r14 18: 4c 89 f7 mov %r14,%rdi 1b: be 04 00 00 00 mov $0x4,%esi 20: e8 0a 1b 68 00 callq 0x681b2f 25: bb 01 00 00 00 mov $0x1,%ebx * 2a: f0 41 0f c1 5c 24 28 lock xadd %ebx,0x28(%r12) <-- trapping instruction 31: 31 ff xor %edi,%edi 33: 89 de mov %ebx,%esi 35: e8 a5 d0 25 00 callq 0x25d0df 3a: 85 db test %ebx,%ebx 3c: 0f .byte 0xf 3d: 84 33 test %dh,(%rbx) 3f: 01 .byte 0x1