INFO: task kworker/u4:5:262 blocked for more than 143 seconds. Not tainted 5.11.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:5 state:D stack:22136 pid: 262 ppid: 2 flags:0x00004000 Workqueue: events_unbound io_ring_exit_work Call Trace: context_switch kernel/sched/core.c:4313 [inline] __schedule+0xa4d/0xf80 kernel/sched/core.c:5064 schedule+0x14b/0x200 kernel/sched/core.c:5143 schedule_timeout+0x98/0x2b0 kernel/time/timer.c:1854 do_wait_for_common+0x2dd/0x450 kernel/sched/completion.c:85 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x43/0x50 kernel/sched/completion.c:138 kthread_park+0x10d/0x1c0 kernel/kthread.c:557 io_sq_thread_park fs/io_uring.c:7408 [inline] io_sq_thread_stop fs/io_uring.c:7426 [inline] io_finish_async+0xd7/0x460 fs/io_uring.c:7444 io_ring_ctx_free fs/io_uring.c:8609 [inline] io_ring_exit_work+0x55/0x4c0 fs/io_uring.c:8702 process_one_work+0x833/0x10c0 kernel/workqueue.c:2275 worker_thread+0xaa4/0x1460 kernel/workqueue.c:2421 kthread+0x39a/0x3c0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Showing all locks held in the system: 3 locks held by kworker/u4:5/262: #0: ffff888010869138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7aa/0x10c0 kernel/workqueue.c:2248 #1: ffffc90001b2fd20 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x7e8/0x10c0 kernel/workqueue.c:2250 #2: ffff88802df6a470 (&sqd->lock){+.+.}-{3:3}, at: io_sq_thread_park fs/io_uring.c:7407 [inline] #2: ffff88802df6a470 (&sqd->lock){+.+.}-{3:3}, at: io_sq_thread_stop fs/io_uring.c:7426 [inline] #2: ffff88802df6a470 (&sqd->lock){+.+.}-{3:3}, at: io_finish_async+0xbb/0x460 fs/io_uring.c:7444 1 lock held by khungtaskd/1647: #0: ffffffff8c311580 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 arch/x86/pci/mmconfig_64.c:151 1 lock held by in:imklog/8146: #0: ffff88801b14e370 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x24e/0x2f0 fs/file.c:947 1 lock held by syz-executor.1/8449: #0: ffff8880218b4d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x37/0x410 net/netfilter/x_tables.c:1206 1 lock held by syz-executor.2/8451: #0: ffff8880218b4d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x37/0x410 net/netfilter/x_tables.c:1206 2 locks held by syz-executor.3/8453: #0: ffff8880218b4d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x37/0x410 net/netfilter/x_tables.c:1206 #1: ffffffff8c315928 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #1: ffffffff8c315928 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x255/0x6d0 kernel/rcu/tree_exp.h:836 1 lock held by syz-executor.4/8455: #0: ffff8880218b4d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x37/0x410 net/netfilter/x_tables.c:1206 1 lock held by syz-executor.5/8498: #0: ffff8880218b4d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x37/0x410 net/netfilter/x_tables.c:1206 2 locks held by kworker/1:8/23398: #0: ffff88801087c538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7aa/0x10c0 kernel/workqueue.c:2248 #1: ffffc900070dfd20 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7e8/0x10c0 kernel/workqueue.c:2250 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1647 Comm: khungtaskd Not tainted 5.11.0-rc3-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+0x183/0x22e lib/dump_stack.c:120 nmi_cpu_backtrace+0x16c/0x190 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x191/0x2f0 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+0xce9/0xd30 kernel/hung_task.c:294 kthread+0x39a/0x3c0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 23398 Comm: kworker/1:8 Not tainted 5.11.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events free_obj_work RIP: 0010:orc_ip arch/x86/kernel/unwind_orc.c:30 [inline] RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:52 [inline] RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:173 [inline] RIP: 0010:unwind_next_frame+0x521/0x1e20 arch/x86/kernel/unwind_orc.c:443 Code: 89 c1 48 c1 f9 02 48 c1 e8 3f 48 01 c8 48 83 e0 fe 49 8d 1c 47 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 <84> c0 75 27 48 63 03 48 01 d8 48 8d 4b 04 4c 39 e0 4c 0f 46 f9 48 RSP: 0018:ffffc900070df5f8 EFLAGS: 00000a07 RAX: 0000000000000000 RBX: ffffffff8d877e54 RCX: dffffc0000000000 RDX: ffffffff8df063e6 RSI: ffffffff81c2d701 RDI: ffffffff8136ebdd RBP: ffffffff8d877e44 R08: 000000000000000a R09: ffffc900070df790 R10: fffff52000e1bee4 R11: 0000000000000000 R12: ffffffff81c2d7de R13: ffffffff8d877e68 R14: ffffffff8d877e44 R15: ffffffff8d877e44 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000015a0004 CR3: 0000000054be5000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0xb2/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x104/0x1e0 kernel/stacktrace.c:121 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x3d/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:356 ____kasan_slab_free+0xe2/0x110 mm/kasan/common.c:362 kasan_slab_free include/linux/kasan.h:188 [inline] slab_free_hook mm/slub.c:1547 [inline] slab_free_freelist_hook+0xd6/0x1a0 mm/slub.c:1580 slab_free mm/slub.c:3142 [inline] kmem_cache_free+0x85/0x160 mm/slub.c:3158 free_obj_work+0x4a7/0x5e0 lib/debugobjects.c:338 process_one_work+0x833/0x10c0 kernel/workqueue.c:2275 worker_thread+0xaa4/0x1460 kernel/workqueue.c:2421 kthread+0x39a/0x3c0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296