Unable to handle kernel NULL pointer dereference at virtual address 000000000000001c Mem abort info: ESR = 0x0000000096000005 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x05: level 1 translation fault Data abort info: ISV = 0, ISS = 0x00000005 CM = 0, WnR = 0 user pgtable: 4k pages, 48-bit VAs, pgdp=000000014d9a3000 [000000000000001c] pgd=0800000151073003, p4d=0800000151073003, pud=0000000000000000 Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP Modules linked in: CPU: 1 PID: 3070 Comm: syz-executor.1 Not tainted 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022 pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : __lse_atomic_fetch_add_relaxed arch/arm64/include/asm/atomic_lse.h:62 [inline] pc : arch_atomic_fetch_add_relaxed arch/arm64/include/asm/atomic.h:49 [inline] pc : atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:117 [inline] pc : __refcount_add include/linux/refcount.h:193 [inline] pc : __refcount_inc include/linux/refcount.h:250 [inline] pc : refcount_inc include/linux/refcount.h:267 [inline] pc : get_task_struct include/linux/sched/task.h:110 [inline] pc : kthread_stop+0x34/0x1c0 kernel/kthread.c:703 lr : __refcount_add include/linux/refcount.h:193 [inline] lr : __refcount_inc include/linux/refcount.h:250 [inline] lr : refcount_inc include/linux/refcount.h:267 [inline] lr : get_task_struct include/linux/sched/task.h:110 [inline] lr : kthread_stop+0x30/0x1c0 kernel/kthread.c:703 sp : ffff800013443c50 x29: ffff800013443c50 x28: ffff0000c5020000 x27: 0000000000000000 x26: ffff80000d30cf28 x25: ffff80000d309000 x24: 0000000000000008 x23: ffffffffffffffff x22: 0000000000000000 x21: 0000000000000000 x20: fffffffffffffff4 x19: 000000000000001c x18: 0000000000000071 x17: ffff80000bffd6bc x16: ffff80000db49158 x15: ffff0000c5020000 x14: 0000000000000000 x13: 00000000ffffffff x12: ffff0000c5020000 x11: ff808000081403c0 x10: 0000000000000000 x9 : ffff8000081403c0 x8 : 0000000000000001 x7 : ffff8000084010ac x6 : 0000000000000000 x5 : ffff0000c5020000 x4 : 0000000000000001 x3 : ffff80000d45be30 x2 : ffff0000c0402670 x1 : 0000000100000000 x0 : 0000000000000000 Call trace: __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+0x34/0x1c0 kernel/kthread.c:703 f2fs_stop_discard_thread+0x3c/0x5c fs/f2fs/segment.c:1638 kill_f2fs_super+0x5c/0x194 fs/f2fs/super.c:4522 deactivate_locked_super+0x70/0xe8 fs/super.c:332 deactivate_super+0xd0/0xd4 fs/super.c:363 cleanup_mnt+0x1f8/0x234 fs/namespace.c:1186 __cleanup_mnt+0x20/0x30 fs/namespace.c:1193 task_work_run+0xc4/0x14c kernel/task_work.c:177 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x174/0x1f0 arch/arm64/kernel/signal.c:1127 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x9c/0x150 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 Code: 9100a293 d503201f 94057e16 52800028 (b8280275) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: 9100a293 add x19, x20, #0x28 4: d503201f nop 8: 94057e16 bl 0x15f860 c: 52800028 mov w8, #0x1 // #1 * 10: b8280275 ldadd w8, w21, [x19] <-- trapping instruction