INFO: task hung in rcu_is_watching (3)

Status: auto-obsoleted due to no activity on 2025/11/29 19:41
Subsystems: kernel
[Documentation on labels]
First crash: 379d, last: 368d
▶ ▼ Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in rcu_is_watching (2) kernel 1 1 642d 642d 0/29 auto-obsoleted due to no activity on 2025/02/28 17:14
upstream INFO: task hung in rcu_is_watching kernel 1 1 752d 752d 0/29 auto-obsoleted due to no activity on 2024/11/10 17:08

Sample crash report:
INFO: task kworker/R-ipv6_:3200 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/R-ipv6_ state:D stack:25848 pid:3200  tgid:3200  ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x81b/0x1060 kernel/locking/mutex.c:760
 rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
 rcu_is_watching+0x12/0xc0 kernel/rcu/tree.c:751

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/20 17:06 upstream b19a97d57c15 bd178e57 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in rcu_is_watching
2025/08/31 19:33 linux-next 7fa4d8dc380f 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: task hung in rcu_is_watching
2025/08/22 22:13 linux-next 7fa4d8dc380f bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in rcu_is_watching
* Struck through repros no longer work on HEAD.