INFO: task kworker/u4:12:19345 blocked for more than 143 seconds. Not tainted 5.16.0-rc1-next-20211118-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:12 state:D stack:24496 pid:19345 ppid: 2 flags:0x00004000 Workqueue: nbd-del nbd_dev_remove_work Call Trace: context_switch kernel/sched/core.c:4987 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6268 schedule+0xd2/0x260 kernel/sched/core.c:6341 blk_mq_freeze_queue_wait+0x112/0x160 block/blk-mq.c:178 del_gendisk+0x598/0x860 block/genhd.c:623 nbd_dev_remove+0x3c/0xf0 drivers/block/nbd.c:252 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 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8bb83ba0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 1 lock held by systemd-udevd/2973: 1 lock held by in:imklog/6222: #0: ffff888072415270 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 2 locks held by agetty/6338: #0: ffff88801ceaa098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:252 #1: ffffc900029d82e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2113 6 locks held by kworker/0:9/10265: 2 locks held by kworker/u4:11/19344: #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline] #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline] #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269 #1: ffffc900051cfdb0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273 2 locks held by kworker/u4:12/19345: #0: ffff88801b3c7138 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88801b3c7138 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff88801b3c7138 ((wq_completion)nbd-del){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff88801b3c7138 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline] #0: ffff88801b3c7138 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline] #0: ffff88801b3c7138 ((wq_completion)nbd-del){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269 #1: ffffc900051afdb0 ((work_completion)(&nbd->remove_work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273 3 locks held by kworker/0:29/20479: #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269 #1: ffffc9000c10fdb0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273 #2: ffffffff8d307628 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xb/0x60 net/core/link_watch.c:251 2 locks held by kworker/u4:14/30999: #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/1:0/10240: #0: ffff888010c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888010c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff888010c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline] #0: ffff888010c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline] #0: ffff888010c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269 #1: ffffc900028cfdb0 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273 3 locks held by kworker/1:1/10241: #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269 #1: ffffc900028afdb0 (key_gc_work){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273 #2: ffffffff8bb8cf28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #2: ffffffff8bb8cf28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4fa/0x620 kernel/rcu/tree_exp.h:836 2 locks held by kworker/u4:1/11185: #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline] #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline] #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269 #1: ffffc9000770fdb0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273 2 locks held by syz-executor.0/19640: #0: ffffffff8bbf80a8 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x23/0xf0 kernel/trace/trace_event_perf.c:241 #1: ffffffff8bb8cf28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #1: ffffffff8bb8cf28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d5/0x620 kernel/rcu/tree_exp.h:836 1 lock held by syz-executor.3/19654: #0: ffffffff8d307628 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:684 [inline] #0: ffffffff8d307628 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3a/0x180 drivers/net/tun.c:3402 1 lock held by syz-executor.2/19693: #0: ffff888076c6f410 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:783 [inline] #0: ffff888076c6f410 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: __sock_release+0x86/0x280 net/socket.c:648 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.16.0-rc1-next-20211118-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:111 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:254 [inline] watchdog+0xcb7/0xed0 kernel/hung_task.c:339 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 2960 Comm: systemd-journal Not tainted 5.16.0-rc1-next-20211118-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:irqentry_exit+0x43/0x80 kernel/entry/common.c:400 Code: 00 00 03 75 34 f6 87 91 00 00 00 02 74 0f 40 84 f6 75 2b e8 8f 26 24 f8 e9 5a a7 3c f8 40 84 f6 75 38 c3 65 8b 05 d9 34 c1 76 <85> c0 74 ce 0f 0b f6 87 88 00 00 00 03 74 cc e9 69 ff ff ff e8 94 RSP: 0018:ffffc90001f2f920 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 1ffff11017387494 RSI: 0000000000000000 RDI: ffffc90001f2f928 RBP: 0000000000000000 R08: ffffffff8f16b018 R09: ffffffff8f16b00f R10: ffffffff8f16b017 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f3b185f68c0(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3b13678028 CR3: 000000007f781000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:unwind_next_frame+0x98/0x1ce0 arch/x86/kernel/unwind_orc.c:634 Code: b6 04 02 84 c0 74 08 3c 03 0f 8e 04 0c 00 00 41 8b 2e 31 c0 85 ed 75 3b 48 ba 00 00 00 00 00 fc ff df 48 c7 04 13 00 00 00 00 <48> 8b 8c 24 98 00 00 00 65 48 2b 0c 25 28 00 00 00 0f 85 53 15 00 RSP: 0018:ffffc90001f2f9d0 EFLAGS: 00000286 RAX: 0000000000000001 RBX: 1ffff920003e5f42 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffffc90001f2fe20 RDI: 0000000000000001 RBP: ffffc90001f2fe50 R08: ffffffff8e391600 R09: 0000000000000001 R10: fffff520003e5f60 R11: 000000000008808a R12: ffffc90001f28000 R13: ffffc90001f2fadd R14: ffffc90001f2faa8 R15: ffffc90001f2fadc arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] ____kasan_kmalloc mm/kasan/common.c:472 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:595 [inline] kzalloc include/linux/slab.h:724 [inline] lsm_cred_alloc security/security.c:537 [inline] security_prepare_creds+0x10e/0x190 security/security.c:1692 prepare_creds+0x56e/0x7b0 kernel/cred.c:291 access_override_creds fs/open.c:351 [inline] do_faccessat+0x3f4/0x850 fs/open.c:415 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: 0033:0x7f3b178b19c7 Code: 83 c4 08 48 3d 01 f0 ff ff 73 01 c3 48 8b 0d c8 d4 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 15 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 d4 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffc01db6738 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffc01db9650 RCX: 00007f3b178b19c7 RDX: 00007f3b18322a00 RSI: 0000000000000000 RDI: 000055d82e8e59a3 RBP: 00007ffc01db6770 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ffc01db9650 R15: 00007ffc01db6c60 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 03 75 34 add 0x34(%rbp),%esi 5: f6 87 91 00 00 00 02 testb $0x2,0x91(%rdi) c: 74 0f je 0x1d e: 40 84 f6 test %sil,%sil 11: 75 2b jne 0x3e 13: e8 8f 26 24 f8 callq 0xf82426a7 18: e9 5a a7 3c f8 jmpq 0xf83ca777 1d: 40 84 f6 test %sil,%sil 20: 75 38 jne 0x5a 22: c3 retq 23: 65 8b 05 d9 34 c1 76 mov %gs:0x76c134d9(%rip),%eax # 0x76c13503 * 2a: 85 c0 test %eax,%eax <-- trapping instruction 2c: 74 ce je 0xfffffffc 2e: 0f 0b ud2 30: f6 87 88 00 00 00 03 testb $0x3,0x88(%rdi) 37: 74 cc je 0x5 39: e9 69 ff ff ff jmpq 0xffffffa7 3e: e8 .byte 0xe8 3f: 94 xchg %eax,%esp