INFO: task syz-executor.4:32551 blocked for more than 143 seconds. Not tainted 5.16.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:28480 pid:32551 ppid: 7049 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6253 schedule+0xd2/0x260 kernel/sched/core.c:6326 blk_mq_freeze_queue_wait+0x112/0x160 block/blk-mq.c:178 loop_set_status+0x17d/0x930 drivers/block/loop.c:1264 loop_set_status_old+0x148/0x1b0 drivers/block/loop.c:1396 lo_ioctl+0x3e9/0x17c0 drivers/block/loop.c:1566 blkdev_ioctl+0x37a/0x800 block/ioctl.c:609 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f160244aae9 RSP: 002b:00007f15ff97e188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f160255e0e0 RCX: 00007f160244aae9 RDX: 0000000020000780 RSI: 0000000000004c02 RDI: 0000000000000004 RBP: 00007f16024a4f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1602a91b2f R14: 00007f15ff97e300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8bb83a60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 1 lock held by in:imklog/6382: #0: ffff88801df47c70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 2 locks held by kworker/1:0/30715: #0: ffff8880b9d39a98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2b/0x120 kernel/sched/core.c:478 #1: ffff8880b9d279c8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x3a6/0x490 kernel/sched/psi.c:880 2 locks held by kworker/u4:0/28847: 2 locks held by systemd-udevd/29935: #0: ffff88801a36e918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x9b/0xb50 block/bdev.c:819 #1: ffff88801a36a360 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_open+0x75/0x120 drivers/block/loop.c:1733 1 lock held by syz-executor.4/32551: #0: ffff88801a36a360 (&lo->lo_mutex){+.+.}-{3:3}, at: loop_set_status+0x2a/0x930 drivers/block/loop.c:1248 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.16.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xc1d/0xf50 kernel/hung_task.c:295 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 29538 Comm: kworker/u4:9 Not tainted 5.16.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:__raw_callee_save___pv_queued_spin_unlock+0xc/0x12 Code: 56 57 41 50 41 51 41 52 41 53 e8 af 15 00 00 41 5b 41 5a 41 59 41 58 5f 5e 5a 59 c3 66 90 52 b8 01 00 00 00 31 d2 f0 0f b0 17 <3c> 01 75 02 5a c3 56 0f b6 f0 e8 c5 ff ff ff 5e 5a c3 66 90 48 b8 RSP: 0000:ffffc900191f79c0 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 0000000000000007 RCX: ffffffff815d7230 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff888010dba120 RBP: ffff888010dba120 R08: 0000000000000000 R09: ffff888010dba123 R10: ffffed10021b7424 R11: 000000000000003f R12: ffff888010dba128 R13: ffff888010dba130 R14: 0000000000000b6f R15: ffffffff8bcb0480 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0984959000 CR3: 000000000b88e000 CR4: 00000000003506e0 Call Trace: pv_queued_spin_unlock arch/x86/include/asm/paravirt.h:596 [inline] queued_spin_unlock arch/x86/include/asm/qspinlock.h:56 [inline] do_raw_spin_unlock+0x171/0x230 kernel/locking/spinlock_debug.c:141 __raw_spin_unlock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_unlock+0x1a/0x40 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:389 [inline] __text_poke+0x5d4/0x8c0 arch/x86/kernel/alternative.c:1059 text_poke_bp_batch+0x3d7/0x560 arch/x86/kernel/alternative.c:1361 text_poke_flush arch/x86/kernel/alternative.c:1451 [inline] text_poke_flush arch/x86/kernel/alternative.c:1448 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1458 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d5/0x430 kernel/jump_label.c:830 static_key_enable_cpuslocked+0x1b1/0x260 kernel/jump_label.c:177 static_key_enable+0x16/0x20 kernel/jump_label.c:190 toggle_allocation_gate mm/kfence/core.c:732 [inline] toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:724 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 56 push %rsi 1: 57 push %rdi 2: 41 50 push %r8 4: 41 51 push %r9 6: 41 52 push %r10 8: 41 53 push %r11 a: e8 af 15 00 00 callq 0x15be f: 41 5b pop %r11 11: 41 5a pop %r10 13: 41 59 pop %r9 15: 41 58 pop %r8 17: 5f pop %rdi 18: 5e pop %rsi 19: 5a pop %rdx 1a: 59 pop %rcx 1b: c3 retq 1c: 66 90 xchg %ax,%ax 1e: 52 push %rdx 1f: b8 01 00 00 00 mov $0x1,%eax 24: 31 d2 xor %edx,%edx 26: f0 0f b0 17 lock cmpxchg %dl,(%rdi) * 2a: 3c 01 cmp $0x1,%al <-- trapping instruction 2c: 75 02 jne 0x30 2e: 5a pop %rdx 2f: c3 retq 30: 56 push %rsi 31: 0f b6 f0 movzbl %al,%esi 34: e8 c5 ff ff ff callq 0xfffffffe 39: 5e pop %rsi 3a: 5a pop %rdx 3b: c3 retq 3c: 66 90 xchg %ax,%ax 3e: 48 rex.W 3f: b8 .byte 0xb8