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: 285d, last: 10h32m
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 425d 425d 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 739d 735d 0/29 auto-obsoleted due to no activity on 2024/04/04 23:04

Sample crash report:
INFO: task kworker/u11:3:31421 blocked for more than 143 seconds.
      Tainted: G     U       L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u11:3   state:D stack:26904 pid:31421 tgid:31421 ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5295 [inline]
 __schedule+0xfee/0x6020 kernel/sched/core.c:6907
 __schedule_loop kernel/sched/core.c:6989 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7004
 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:4083
 rds_tcp_listen_stop+0x104/0x160 net/rds/tcp_listen.c:465
 rds_tcp_kill_sock net/rds/tcp.c:605 [inline]
 rds_tcp_exit_net+0xe0/0x870 net/rds/tcp.c:630
 ops_exit_list net/core/net_namespace.c:199 [inline]
 ops_undo_list+0x2ee/0xab0 net/core/net_namespace.c:252
 cleanup_net+0x499/0x920 net/core/net_namespace.c:704
 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3275
 process_scheduled_works kernel/workqueue.c:3358 [inline]
 worker_thread+0x5da/0xe40 kernel/workqueue.c:3439
 kthread+0x370/0x450 kernel/kthread.c:467
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e7e7460 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 #0: ffffffff8e7e7460 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
 #0: ffffffff8e7e7460 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
3 locks held by kworker/u11:3/31421:
 #0: ffff88801c6a6948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3250
 #1: ffffc900033d7d08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3251
 #2: ffffffff905f10f0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:675
1 lock held by syz.3.8498/31593:
 #0: ffffffff905f10f0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:577
1 lock held by syz.1.8709/32617:
 #0: ffffffff905f10f0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:577

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G     U       L      syzkaller #0 PREEMPT(full) 
Tainted: [U]=USER, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
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+0x370/0x450 kernel/kthread.c:467
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G     U       L      syzkaller #0 PREEMPT(full) 
Tainted: [U]=USER, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: 1e 94 02 c3 cc cc cc cc 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 23 ac 2d 00 fb f4 <e9> 3c 34 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df0 EFLAGS: 00000246
RAX: 0000000000269f4b RBX: ffff88801e6d8000 RCX: ffffffff8b7dec75
RDX: 0000000000000000 RSI: ffffffff8de73cdb RDI: ffffffff8c1ad620
RBP: 0000000000000001 R08: 0000000000000001 R09: ffffed10170a6755
R10: ffff8880b8533aab R11: 0000000000000000 R12: ffffed1003cdb000
R13: 0000000000000001 R14: ffffffff90d8f5d0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888124492000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7d670f7910 CR3: 0000000076d7e000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:73 [inline]
 default_idle+0x9/0x10 arch/x86/kernel/process.c:767
 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:191 [inline]
 do_idle+0x35b/0x4b0 kernel/sched/idle.c:332
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x148
 </TASK>

Crashes (195):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/13 05:25 upstream 7449f86bafcd 6a673c50 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/02/13 00:31 upstream 37a93dd5c49b 504cb1bf .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/02/12 00:15 upstream 1e83ccd5921a 76a109e2 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/02/11 12:06 upstream 192c0159402e 75707236 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/02/09 17:23 upstream 05f7e89ab973 df949cd9 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/02/09 00:35 upstream e98f34af6116 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/02/08 19:33 upstream e98f34af6116 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/02/08 12:10 upstream e7aa57247700 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/02/08 07:31 upstream e7aa57247700 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/02/07 20:13 upstream e7aa57247700 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/02/07 13:12 upstream 2687c848e578 f20fc9f9 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/02/07 11:16 upstream 2687c848e578 f20fc9f9 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/02/06 17:21 upstream b7ff7151e653 97745f52 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/02/06 16:16 upstream b7ff7151e653 97745f52 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/02/06 16:13 upstream b7ff7151e653 97745f52 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/02/06 12:14 upstream b7ff7151e653 97745f52 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/02/03 14:05 upstream 6bd9ed02871f 6df4c87a .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/02/02 13:49 upstream 18f7fcd5e69a 018ebef2 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/02/02 09:32 upstream 18f7fcd5e69a 018ebef2 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/02/02 05:49 upstream 9f2693489ef8 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/02/01 21:51 upstream 9f2693489ef8 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/02/01 09:16 upstream 162b42445b58 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/31 07:24 upstream 283073725700 c75a2f6e .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/31 02:38 upstream 283073725700 c75a2f6e .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/30 23:57 upstream 4d310797262f c75a2f6e .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/30 15:06 upstream 4d310797262f ea6dba22 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/30 09:07 upstream 4d310797262f bfa73b7b .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/29 23:37 upstream 8dfce8991b95 bfa73b7b .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in rds_tcp_listen_stop
2026/01/29 11:43 upstream 8dfce8991b95 aeb6fdd5 .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 23:29 upstream 8dfce8991b95 0adc945e .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 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
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.