INFO: task kworker/u4:5:193 blocked for more than 143 seconds. Not tainted 5.11.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:5 state:D stack:25640 pid: 193 ppid: 2 flags:0x00004000 Workqueue: events_unbound io_ring_exit_work Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5078 schedule+0xcf/0x270 kernel/sched/core.c:5157 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1854 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x163/0x260 kernel/sched/completion.c:138 kthread_park+0x122/0x1b0 kernel/kthread.c:582 io_sq_thread_park fs/io_uring.c:7462 [inline] io_sq_thread_park fs/io_uring.c:7456 [inline] io_sq_thread_stop+0xfe/0x570 fs/io_uring.c:7480 io_finish_async fs/io_uring.c:7498 [inline] io_ring_ctx_free fs/io_uring.c:8663 [inline] io_ring_exit_work+0x62/0x6d0 fs/io_uring.c:8756 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Showing all locks held in the system: 2 locks held by kworker/1:0/19: #0: ffff888010073538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010073538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888010073538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888010073538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888010073538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888010073538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x871/0x15f0 kernel/workqueue.c:2246 #1: ffffc90000dafda8 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x15f0 kernel/workqueue.c:2250 2 locks held by kworker/u4:2/46: 3 locks held by kworker/u4:5/193: #0: ffff888010071138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010071138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888010071138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888010071138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888010071138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888010071138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x871/0x15f0 kernel/workqueue.c:2246 #1: ffffc90001767da8 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x15f0 kernel/workqueue.c:2250 #2: ffff88801153f070 (&sqd->lock){+.+.}-{3:3}, at: io_sq_thread_park fs/io_uring.c:7461 [inline] #2: ffff88801153f070 (&sqd->lock){+.+.}-{3:3}, at: io_sq_thread_park fs/io_uring.c:7456 [inline] #2: ffff88801153f070 (&sqd->lock){+.+.}-{3:3}, at: io_sq_thread_stop+0xd6/0x570 fs/io_uring.c:7480 1 lock held by khungtaskd/1648: #0: ffffffff8b373ce0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6259 1 lock held by systemd-udevd/4886: 1 lock held by in:imklog/8359: #0: ffff88801e37c670 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:947 2 locks held by syz-executor.0/8475: #0: ffff888022f4cd88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x41/0x540 net/netfilter/x_tables.c:1206 #1: ffffffff8b37c5a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #1: ffffffff8b37c5a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x27e/0x610 kernel/rcu/tree_exp.h:836 2 locks held by syz-executor.1/8477: #0: ffff888022f4c308 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x41/0x540 net/netfilter/x_tables.c:1206 #1: ffffffff8b37c5a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #1: ffffffff8b37c5a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x27e/0x610 kernel/rcu/tree_exp.h:836 1 lock held by syz-executor.3/8481: #0: ffff888022f4c308 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x41/0x540 net/netfilter/x_tables.c:1206 1 lock held by syz-executor.4/8483: #0: ffff888022f4cd88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x41/0x540 net/netfilter/x_tables.c:1206 1 lock held by syz-executor.5/8541: #0: ffff888022f4cd88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x41/0x540 net/netfilter/x_tables.c:1206 1 lock held by syz-executor.2/16707: #0: ffff888025a09858 (&mm->mmap_lock#2){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #0: ffff888025a09858 (&mm->mmap_lock#2){++++}-{3:3}, at: vm_mmap_pgoff+0x15c/0x290 mm/util.c:517 4 locks held by syz-executor.2/16712: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1648 Comm: khungtaskd Not tainted 5.11.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 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:209 [inline] watchdog+0xd43/0xfa0 kernel/hung_task.c:294 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 16729 Comm: syz-executor.0 Not tainted 5.11.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__this_cpu_preempt_check+0x0/0x20 lib/smp_processor_id.c:69 Code: 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 c7 c6 e0 82 9e 89 48 c7 c7 20 83 9e 89 e9 98 fe ff ff 0f 1f 84 00 00 00 00 00 <55> 48 89 fd 0f 1f 44 00 00 48 89 ee 5d 48 c7 c7 60 83 9e 89 e9 77 RSP: 0018:ffffc900164ffa30 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff894baa20 RBP: ffffffff8b373c20 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81d05077 R11: 0000000000000000 R12: ffff888078e46180 R13: 0000000000000001 R14: 00000000ffffffff R15: ffff88807aaf0698 FS: 0000000001b09940(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000778000 CR3: 000000002c8fb000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:432 [inline] lock_is_held_type+0x63/0x120 kernel/locking/lockdep.c:5480 lock_is_held include/linux/lockdep.h:271 [inline] rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:123 trace_block_touch_buffer include/trace/events/block.h:45 [inline] touch_buffer fs/buffer.c:62 [inline] __find_get_block+0xb17/0xd30 fs/buffer.c:1332 sb_find_get_block include/linux/buffer_head.h:338 [inline] recently_deleted fs/ext4/ialloc.c:686 [inline] find_inode_bit+0x224/0x570 fs/ext4/ialloc.c:728 __ext4_new_inode+0xc54/0x5570 fs/ext4/ialloc.c:1062 ext4_symlink+0x480/0xd40 fs/ext4/namei.c:3336 vfs_symlink fs/namei.c:3962 [inline] vfs_symlink+0x44e/0x690 fs/namei.c:3948 do_symlinkat+0x258/0x2c0 fs/namei.c:3989 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45df47 Code: 0f 1f 00 b8 5c 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 cd b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 58 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffe750d6058 EFLAGS: 00000202 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000045df47 RDX: 00007ffe750d6113 RSI: 00000000004c3c8c RDI: 00007ffe750d6100 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000013 R10: 0000000000000075 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000