================================================================== 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:116 [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:110 [inline] BUG: KASAN: null-ptr-deref in kthread_stop+0x2a/0x210 kernel/kthread.c:703 Write of size 4 at addr 0000000000000024 by task syz-executor.1/3636 CPU: 0 PID: 3636 Comm: syz-executor.1 Not tainted 6.0.0-syzkaller-09589-g55be6084c8e0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_report+0xf1/0x220 mm/kasan/report.c:436 kasan_report+0xfb/0x130 mm/kasan/report.c:495 kasan_check_range+0x2a7/0x2e0 mm/kasan/generic.c:189 instrument_atomic_read_write include/linux/instrumented.h:101 [inline] atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:116 [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:110 [inline] kthread_stop+0x2a/0x210 kernel/kthread.c:703 kill_f2fs_super+0xe6/0x3c0 fs/f2fs/super.c:4522 deactivate_locked_super+0xa7/0xf0 fs/super.c:331 cleanup_mnt+0x4ce/0x560 fs/namespace.c:1186 task_work_run+0x146/0x1c0 kernel/task_work.c:177 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0x134/0x160 kernel/entry/common.c:169 exit_to_user_mode_prepare+0xad/0x110 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x2e/0x60 kernel/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f620a48ca17 Code: ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 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 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffde1269898 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f620a48ca17 RDX: 00007ffde126996c RSI: 000000000000000a RDI: 00007ffde1269960 RBP: 00007ffde1269960 R08: 00000000ffffffff R09: 00007ffde1269730 R10: 0000555555bfa8b3 R11: 0000000000000246 R12: 00007f620a4e55f6 R13: 00007ffde126aa20 R14: 0000555555bfa810 R15: 00007ffde126aa60 ==================================================================