INFO: task syz-executor.4:10861 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:26848 pid:10861 ppid: 7033 flags:0x20004004 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 del_gendisk+0x598/0x860 block/genhd.c:623 loop_remove+0x39/0xf0 drivers/block/loop.c:2080 loop_control_remove drivers/block/loop.c:2137 [inline] loop_control_ioctl+0x445/0x4a0 drivers/block/loop.c:2175 __do_compat_sys_ioctl+0x1c7/0x290 fs/ioctl.c:972 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c RIP: 0023:0xf6ea1549 RSP: 002b:00000000f449b5fc EFLAGS: 00000296 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000004c81 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8bb83ae0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 1 lock held by in:imklog/6448: #0: ffff88801fa62af0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 ============================================= 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: 8 Comm: kworker/u4:0 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:check_preemption_disabled+0x2/0x170 lib/smp_processor_id.c:13 Code: 1f 44 00 00 e8 ef ea 49 f8 65 48 8b 3c 25 40 70 02 00 e8 51 f0 00 f8 eb 99 0f 1f 44 00 00 0f 0b e9 23 ff ff ff cc cc cc 41 56 <41> 55 49 89 f5 41 54 55 48 89 fd 53 0f 1f 44 00 00 65 44 8b 25 7d RSP: 0018:ffffc90000cd78f0 EFLAGS: 00000286 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff815cfc31 RDX: fffffbfff1b22e6b RSI: ffffffff8a0516e0 RDI: ffffffff8a051720 RBP: 1ffff9200019af27 R08: 0000000000000000 R09: ffffffff8d917357 R10: fffffbfff1b22e6a R11: 000000000000003f R12: 0000000000000001 R13: 0000000000000001 R14: 0000000000000824 R15: ffffffff8bcb0500 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f84b7428000 CR3: 000000000b88e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:330 [inline] rcu_is_watching+0xe/0xb0 kernel/rcu/tree.c:1121 rcu_read_lock_held_common kernel/rcu/update.c:108 [inline] rcu_read_lock_sched_held+0x1c/0x70 kernel/rcu/update.c:123 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x522/0x720 kernel/locking/lockdep.c:5648 __raw_spin_unlock include/linux/spinlock_api_smp.h:141 [inline] _raw_spin_unlock+0x12/0x40 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+0x187/0x560 arch/x86/kernel/alternative.c:1294 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_disable_cpuslocked+0x152/0x1b0 kernel/jump_label.c:207 static_key_disable+0x16/0x20 kernel/jump_label.c:215 toggle_allocation_gate mm/kfence/core.c:746 [inline] toggle_allocation_gate+0x183/0x390 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), 1 bytes skipped: 0: 44 00 00 add %r8b,(%rax) 3: e8 ef ea 49 f8 callq 0xf849eaf7 8: 65 48 8b 3c 25 40 70 mov %gs:0x27040,%rdi f: 02 00 11: e8 51 f0 00 f8 callq 0xf800f067 16: eb 99 jmp 0xffffffb1 18: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 1d: 0f 0b ud2 1f: e9 23 ff ff ff jmpq 0xffffff47 24: cc int3 25: cc int3 26: cc int3 27: 41 56 push %r14 * 29: 41 55 push %r13 <-- trapping instruction 2b: 49 89 f5 mov %rsi,%r13 2e: 41 54 push %r12 30: 55 push %rbp 31: 48 89 fd mov %rdi,%rbp 34: 53 push %rbx 35: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 3a: 65 gs 3b: 44 rex.R 3c: 8b .byte 0x8b 3d: 25 .byte 0x25 3e: 7d .byte 0x7d