INFO: task hung in io_wq_put_and_exit (5)

Status: closed as invalid on 2025/08/13 14:32
Subsystems: io-uring input usb
[Documentation on labels]
Reported-by: syzbot+e328767eafd849df0a78@syzkaller.appspotmail.com
First crash: 424d, last: 367d
Cause bisection: introduced by (bisect log) :
commit e5598d6ae62626d261b046a2f19347c38681ff51
Author: Pavel Begunkov <asml.silence@gmail.com>
Date: Thu Aug 24 22:53:31 2023 +0000

  io_uring: compact SQ/CQ heads/tails

Crash: INFO: task hung in io_wq_put_and_exit (log)
Repro: C syz .config
  
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [input?] [usb?] [io-uring?] INFO: task hung in io_wq_put_and_exit (5) 3 (5) 2025/08/14 12:04
▶ ▼ Similar bugs (8)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in io_wq_put_and_exit (6) io-uring 1 syz, C error 74 201d 360d 29/29 fixed on 2026/05/06 16:40
linux-5.15 INFO: task hung in io_wq_put_and_exit 1 1 885d 885d 0/3 auto-obsoleted due to no activity on 2024/06/19 08:55
linux-6.6 INFO: task hung in io_wq_put_and_exit origin:lts-only 1 syz, C done 15 8d20h 414d 0/2 upstream: reported C repro on 2025/06/25 22:50
upstream INFO: task hung in io_wq_put_and_exit (3) io-uring 1 syz, C error unreliable 75 1209d 1604d 0/29 auto-obsoleted due to no activity on 2023/08/20 08:26
upstream INFO: task hung in io_wq_put_and_exit io-uring fs 1 syz, C unreliable 628 1738d 1799d 20/29 fixed on 2021/11/10 00:50
upstream INFO: task hung in io_wq_put_and_exit (2) fs 1 22 1707d 1736d 0/29 closed as invalid on 2022/02/08 09:40
upstream INFO: task hung in io_wq_put_and_exit (4) io-uring 1 syz, C unreliable 86 433d 663d 28/29 fixed on 2025/06/10 16:19
linux-6.1 INFO: task hung in io_wq_put_and_exit 1 syz, C 3 7d11h 9d01h 0/3 upstream: reported C repro on 2026/08/04 21:15
▶ ▼ Last patch testing requests (2)
Created Duration User Patch Repo Result
2025/08/05 04:17 39m retest repro upstream report log
2025/07/24 03:13 21m hdanton@sina.com patch upstream report log

Sample crash report:
INFO: task syz-executor971:5849 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc6-syzkaller-00279-gbf61759db409 #0
      Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor971 state:D stack:26488 pid:5849  tgid:5849  ppid:5844   task_flags:0x400148 flags:0x00024002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x116a/0x5de0 kernel/sched/core.c:6786
 __schedule_loop kernel/sched/core.c:6864 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6879
 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common+0x2ff/0x4e0 kernel/sched/completion.c:116
 io_wq_exit_workers io_uring/io-wq.c:1319 [inline]
 io_wq_put_and_exit+0x271/0x8d0 io_uring/io-wq.c:1347
 io_uring_clean_tctx+0x10d/0x190 io_uring/tctx.c:203
 io_uring_cancel_generic+0x69c/0x9a0 io_uring/io_uring.c:3212
 io_uring_files_cancel include/linux/io_uring.h:19 [inline]
 do_exit+0x2ce/0x2bd0 kernel/exit.c:911
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1105
 __do_sys_exit_group kernel/exit.c:1116 [inline]
 __se_sys_exit_group kernel/exit.c:1114 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1114
 x64_sys_call+0x1530/0x1730 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f141ec08e39
RSP: 002b:00007ffcd1b0b6e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f141ec08e39
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 00007f141ec843b0 R08: ffffffffffffffb8 R09: 0000000000000000
R10: 000000000000000e R11: 0000000000000246 R12: 00007f141ec843b0
R13: 0000000000000000 R14: 00007f141ec880c0 R15: 00007f141ebd7020
 </TASK>
INFO: task syz-executor971:5850 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc6-syzkaller-00279-gbf61759db409 #0
      Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor971 state:D stack:26488 pid:5850  tgid:5850  ppid:5846   task_flags:0x400148 flags:0x00024002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x116a/0x5de0 kernel/sched/core.c:6786
 __schedule_loop kernel/sched/core.c:6864 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6879
 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common+0x2ff/0x4e0 kernel/sched/completion.c:116
 io_wq_exit_workers io_uring/io-wq.c:1319 [inline]
 io_wq_put_and_exit+0x271/0x8d0 io_uring/io-wq.c:1347
 io_uring_clean_tctx+0x10d/0x190 io_uring/tctx.c:203
 io_uring_cancel_generic+0x69c/0x9a0 io_uring/io_uring.c:3212
 io_uring_files_cancel include/linux/io_uring.h:19 [inline]
 do_exit+0x2ce/0x2bd0 kernel/exit.c:911
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1105
 __do_sys_exit_group kernel/exit.c:1116 [inline]
 __se_sys_exit_group kernel/exit.c:1114 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1114
 x64_sys_call+0x1530/0x1730 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f141ec08e39
RSP: 002b:00007ffcd1b0b6e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f141ec08e39
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 00007f141ec843b0 R08: ffffffffffffffb8 R09: 0000000000000000
R10: 000000000000000e R11: 0000000000000246 R12: 00007f141ec843b0
R13: 0000000000000000 R14: 00007f141ec880c0 R15: 00007f141ebd7020
 </TASK>
INFO: task syz-executor971:5851 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc6-syzkaller-00279-gbf61759db409 #0
      Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor971 state:D stack:27256 pid:5851  tgid:5851  ppid:5845   task_flags:0x400148 flags:0x00024002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x116a/0x5de0 kernel/sched/core.c:6786
 __schedule_loop kernel/sched/core.c:6864 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6879
 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common+0x2ff/0x4e0 kernel/sched/completion.c:116
 io_wq_exit_workers io_uring/io-wq.c:1319 [inline]
 io_wq_put_and_exit+0x271/0x8d0 io_uring/io-wq.c:1347
 io_uring_clean_tctx+0x10d/0x190 io_uring/tctx.c:203
 io_uring_cancel_generic+0x69c/0x9a0 io_uring/io_uring.c:3212
 io_uring_files_cancel include/linux/io_uring.h:19 [inline]
 do_exit+0x2ce/0x2bd0 kernel/exit.c:911
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1105
 __do_sys_exit_group kernel/exit.c:1116 [inline]
 __se_sys_exit_group kernel/exit.c:1114 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1114
 x64_sys_call+0x1530/0x1730 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f141ec08e39
RSP: 002b:00007ffcd1b0b6e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f141ec08e39
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 00007f141ec843b0 R08: ffffffffffffffb8 R09: 0000000000000000
R10: 000000000000000e R11: 0000000000000246 R12: 00007f141ec843b0
R13: 0000000000000000 R14: 00007f141ec880c0 R15: 00007f141ebd7020
 </TASK>
INFO: task syz-executor971:5852 blocked for more than 144 seconds.
      Not tainted 6.16.0-rc6-syzkaller-00279-gbf61759db409 #0
      Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor971 state:D stack:26312 pid:5852  tgid:5852  ppid:5848   task_flags:0x400148 flags:0x00024002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x116a/0x5de0 kernel/sched/core.c:6786
 __schedule_loop kernel/sched/core.c:6864 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6879
 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common+0x2ff/0x4e0 kernel/sched/completion.c:116
 io_wq_exit_workers io_uring/io-wq.c:1319 [inline]
 io_wq_put_and_exit+0x271/0x8d0 io_uring/io-wq.c:1347
 io_uring_clean_tctx+0x10d/0x190 io_uring/tctx.c:203
 io_uring_cancel_generic+0x69c/0x9a0 io_uring/io_uring.c:3212
 io_uring_files_cancel include/linux/io_uring.h:19 [inline]
 do_exit+0x2ce/0x2bd0 kernel/exit.c:911
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1105
 __do_sys_exit_group kernel/exit.c:1116 [inline]
 __se_sys_exit_group kernel/exit.c:1114 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1114
 x64_sys_call+0x1530/0x1730 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f141ec08e39
RSP: 002b:00007ffcd1b0b6e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f141ec08e39
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 00007f141ec843b0 R08: ffffffffffffffb8 R09: 0000000000000000
R10: 000000000000000e R11: 0000000000000246 R12: 00007f141ec843b0
R13: 0000000000000000 R14: 00007f141ec880c0 R15: 00007f141ebd7020
 </TASK>
INFO: task syz-executor971:5853 blocked for more than 144 seconds.
      Not tainted 6.16.0-rc6-syzkaller-00279-gbf61759db409 #0
      Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor971 state:D stack:27080 pid:5853  tgid:5853  ppid:5847   task_flags:0x400148 flags:0x00024002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x116a/0x5de0 kernel/sched/core.c:6786
 __schedule_loop kernel/sched/core.c:6864 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6879
 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common+0x2ff/0x4e0 kernel/sched/completion.c:116
 io_wq_exit_workers io_uring/io-wq.c:1319 [inline]
 io_wq_put_and_exit+0x271/0x8d0 io_uring/io-wq.c:1347
 io_uring_clean_tctx+0x10d/0x190 io_uring/tctx.c:203
 io_uring_cancel_generic+0x69c/0x9a0 io_uring/io_uring.c:3212
 io_uring_files_cancel include/linux/io_uring.h:19 [inline]
 do_exit+0x2ce/0x2bd0 kernel/exit.c:911
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1105
 __do_sys_exit_group kernel/exit.c:1116 [inline]
 __se_sys_exit_group kernel/exit.c:1114 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1114
 x64_sys_call+0x1530/0x1730 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f141ec08e39
RSP: 002b:00007ffcd1b0b6e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f141ec08e39
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 00007f141ec843b0 R08: ffffffffffffffb8 R09: 0000000000000000
R10: 000000000000000e R11: 0000000000000246 R12: 00007f141ec843b0
R13: 0000000000000000 R14: 00007f141ec880c0 R15: 00007f141ebd7020
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770
2 locks held by getty/5594:
 #0: ffff888032cc90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc900036cb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222

=============================================

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc6-syzkaller-00279-gbf61759db409 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
 watchdog+0xf70/0x12c0 kernel/hung_task.c:470
 kthread+0x3c5/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.16.0-rc6-syzkaller-00279-gbf61759db409 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 7b 6d 02 e9 83 fb 02 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 43 99 23 00 fb f4 <c3> cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e207e08 EFLAGS: 000002c6
RAX: 00000000000d6725 RBX: 0000000000000000 RCX: ffffffff8b867c99
RDX: 0000000000000000 RSI: ffffffff8de2fff6 RDI: ffffffff8c157460
RBP: fffffbfff1c52ef0 R08: 0000000000000001 R09: ffffed1017086645
R10: ffff8880b843322b R11: 0000000000000001 R12: 0000000000000000
R13: ffffffff8e297780 R14: ffffffff90a94550 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888124720000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e50c02d168 CR3: 000000000e382000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:749
 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117
 cpuidle_idle_call kernel/sched/idle.c:185 [inline]
 do_idle+0x391/0x510 kernel/sched/idle.c:325
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423
 rest_init+0x16b/0x2b0 init/main.c:745
 start_kernel+0x3ee/0x4d0 init/main.c:1102
 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:307
 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:288
 common_startup_64+0x13e/0x148
 </TASK>

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/20 10:54 upstream bf61759db409 7117feec .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in io_wq_put_and_exit
2025/08/11 12:57 upstream 8f5ae30d69d7 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in io_wq_put_and_exit
2025/08/11 02:09 upstream 038d61fd6422 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in io_wq_put_and_exit
2025/08/10 20:07 upstream 2b38afce25c4 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in io_wq_put_and_exit
2025/08/07 18:07 upstream 6e64f4580381 04cffc22 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in io_wq_put_and_exit
2025/07/22 01:40 upstream 89be9a83ccf1 0b3788a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in io_wq_put_and_exit
2025/07/20 06:11 upstream bf61759db409 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in io_wq_put_and_exit
2025/07/10 06:05 upstream 8c2e52ebbe88 956bd956 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in io_wq_put_and_exit
2025/06/15 01:24 upstream 4774cfe3543a 5f4b362d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in io_wq_put_and_exit
* Struck through repros no longer work on HEAD.