syzbot


INFO: task hung in rds_tcp_listen_stop (3)

Status: upstream: reported on 2025/09/20 12:19
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+b3b8ea37bd20c5ffe24c@syzkaller.appspotmail.com
First crash: 269d, last: 6h06m
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [kernel?] INFO: task hung in rds_tcp_listen_stop (3) 0 (1) 2025/09/20 12:19
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in rds_tcp_listen_stop (2) kernel 1 1 409d 409d 0/29 auto-obsoleted due to no activity on 2025/03/15 02:18
upstream INFO: task hung in rds_tcp_listen_stop rds 1 9 723d 719d 0/29 auto-obsoleted due to no activity on 2024/04/04 23:04

Sample crash report:
INFO: task kworker/u8:9:19082 blocked for more than 143 seconds.
      Tainted: G     U  W    L XTNJ syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:9    state:D stack:24056 pid:19082 tgid:19082 ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5260 [inline]
 __schedule+0xfe4/0x5e10 kernel/sched/core.c:6867
 __schedule_loop kernel/sched/core.c:6949 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:6964
 schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:100 [inline]
 __wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121
 __flush_workqueue+0x3f7/0x1200 kernel/workqueue.c:4033
 rds_tcp_listen_stop+0x104/0x160 net/rds/tcp_listen.c:331
 rds_tcp_kill_sock net/rds/tcp.c:611 [inline]
 rds_tcp_exit_net+0xcb/0x810 net/rds/tcp.c:634
 ops_exit_list net/core/net_namespace.c:199 [inline]
 ops_undo_list+0x2ee/0xab0 net/core/net_namespace.c:252
 cleanup_net+0x419/0x830 net/core/net_namespace.c:696
 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
 kthread+0x3b3/0x730 kernel/kthread.c:463
 ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e5e3120 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e5e3120 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8e5e3120 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
1 lock held by syslogd/5177:
 #0: ffff8880b843add8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:647 [inline]
 #0: ffff8880b843add8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:632
2 locks held by sshd-session/5814:
2 locks held by syz-executor/5831:
1 lock held by syz-executor/5844:
 #0: ffff8880b843add8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:647 [inline]
 #0: ffff8880b843add8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:632
2 locks held by syz.2.3860/17664:
3 locks held by kworker/u8:9/19082:
 #0: ffff88801c29f148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
 #1: ffffc90002fc7c98 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
 #2: ffffffff903dd0b0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xab/0x830 net/core/net_namespace.c:670
2 locks held by syz.2.5986/25554:
2 locks held by kworker/u10:5/25771:
 #0: ffff88801dfec148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
 #1: ffffc9000371fc98 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
1 lock held by syz.5.6079/26010:
1 lock held by syz.1.6152/26345:
 #0: ffffffff903dd0b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:577
1 lock held by syz.4.6190/26547:
 #0: ffffffff903dd0b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:577
1 lock held by syz-executor/26716:
 #0: ffffffff8e5ef8f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
2 locks held by syz.6.6437/27672:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G     U  W    L XTNJ syzkaller #0 PREEMPT(full) 
Tainted: [U]=USER, [W]=WARN, [L]=SOFTLOCKUP, [X]=AUX, [T]=RANDSTRUCT, [N]=TEST, [J]=FWCTL
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x141/0x190 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
 watchdog+0xcc3/0xfe0 kernel/hung_task.c:515
 kthread+0x3b3/0x730 kernel/kthread.c:463
 ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 26010 Comm: syz.5.6079 Tainted: G     U  W    L XTNJ syzkaller #0 PREEMPT(full) 
Tainted: [U]=USER, [W]=WARN, [L]=SOFTLOCKUP, [X]=AUX, [T]=RANDSTRUCT, [N]=TEST, [J]=FWCTL
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
RIP: 0010:__sanitizer_cov_trace_pc+0xb/0x70 kernel/kcov.c:213
Code: 5d 00 be 03 00 00 00 5b e9 32 a5 de 02 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 8b 05 a5 85 dd 11 <48> 8b 34 24 65 48 8b 15 81 85 dd 11 a9 00 01 ff 00 74 1b f6 c4 01
RSP: 0018:ffffc900038ef958 EFLAGS: 00000293
RAX: 0000000080000000 RBX: 000000000000002e RCX: ffffffff81b8064b
RDX: 000000000000002e RSI: 000000000000003f RDI: ffff88802d908000
RBP: 0000000021f3fc00 R08: 0000000000000001 R09: 000000000000003f
R10: 000000000000002e R11: 0000000000000000 R12: 0000000000000000
R13: ffffc900038efa00 R14: 0000000000000000 R15: ffff888032088e40
FS:  0000000000000000(0000) GS:ffff8881246e3000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5ba3f47e20 CR3: 0000000032384000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 phys_addr_valid arch/x86/mm/physaddr.h:7 [inline]
 __phys_addr+0xc9/0x180 arch/x86/mm/physaddr.c:28
 kfree+0x6c/0x690 mm/slub.c:6874
 shmem_put_super+0x112/0x180 mm/shmem.c:4981
 generic_shutdown_super+0x15f/0x360 fs/super.c:643
 kill_anon_super+0x3a/0x60 fs/super.c:1289
 deactivate_locked_super+0xc1/0x1b0 fs/super.c:474
 deactivate_super fs/super.c:507 [inline]
 deactivate_super+0xe7/0x110 fs/super.c:503
 cleanup_mnt+0x21f/0x450 fs/namespace.c:1318
 task_work_run+0x150/0x240 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x829/0x2a30 kernel/exit.c:971
 do_group_exit+0xd5/0x2a0 kernel/exit.c:1112
 get_signal+0x1ec7/0x21e0 kernel/signal.c:3034
 arch_do_signal_or_restart+0x91/0x770 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
 exit_to_user_mode_loop+0x86/0x4b0 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x4ea/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd1c795b78e
Code: Unable to access opcode bytes at 0x7fd1c795b764.
RSP: 002b:00007fd1c8785f58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007fd1c87866c0 RCX: 00007fd1c795b78e
RDX: 00007fd1c8785fb0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fd1c7a08c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd1c7c16038 R14: 00007fd1c7c15fa0 R15: 00007ffe7389dc78
 </TASK>

Crashes (162):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/28 11:22 upstream 1f97d9dcf536 1f9bbf06 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/28 09:15 upstream 1f97d9dcf536 3029c699 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/28 00:56 upstream 1f97d9dcf536 3029c699 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/26 21:59 upstream fcb70a56f4d8 efb3e894 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/25 04:38 upstream 5dbeeb268b63 40acda8a .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/24 22:10 upstream 62085877ae65 40acda8a .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/23 19:18 upstream c072629f05d7 1aa92270 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/23 00:55 upstream a66191c590b3 82c9c083 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/22 13:21 upstream a66191c590b3 a16aed1d .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/22 07:24 upstream cf38b2340c0e d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/19 21:06 upstream 24d479d26b25 d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/17 07:38 upstream 39d3389331ab d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/16 06:50 upstream 603c05a1639f d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/15 13:48 upstream 944aacb68baf d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/15 07:34 upstream 944aacb68baf d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/14 00:44 upstream b54345928fa1 d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/10 16:55 upstream b6151c4e60e5 d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/09 04:52 upstream 79b95d74470d d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/09 02:27 upstream 79b95d74470d d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/02 02:40 upstream b69053dd3ffb d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/12/30 11:57 upstream 8640b74557fc d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/12/29 14:43 upstream 7839932417dd d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/12/27 04:48 upstream 3f0e9c8cefa9 d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/12/26 03:13 upstream ccd1cdca5cd4 d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/12/23 22:03 upstream b927546677c8 d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/12/23 15:45 upstream b927546677c8 d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/12/22 17:35 upstream 9448598b22c5 d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/12/17 22:50 upstream ea1013c15392 d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/12/17 16:25 upstream ea1013c15392 d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/12/14 12:57 upstream 8f0b4cce4481 d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/12/14 03:46 upstream 9d9c1cfec01c d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/12/12 15:58 upstream 187d0801404f d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/12/12 13:25 upstream 187d0801404f d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/12/12 04:47 upstream d358e5254674 d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/12/11 08:48 upstream 5c179cac0519 d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/12/11 06:52 upstream 5c179cac0519 d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/12/09 06:48 upstream cb015814f8b6 d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/12/09 04:38 upstream c2f2b01b74be d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/12/08 21:29 upstream c2f2b01b74be d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/12/07 22:15 upstream 37bb2e7217b0 d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/12/07 17:39 upstream 37bb2e7217b0 d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/12/07 12:21 upstream cc3ee4ba57b7 d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/12/07 11:21 upstream cc3ee4ba57b7 d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/09/20 00:14 upstream 1522b530ac3e 67c37560 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/09/17 00:35 upstream 5aca7966d2a7 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2025/06/10 19:49 upstream f09079bd04a9 5d7e17ca .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
* Struck through repros no longer work on HEAD.