syzbot


INFO: task hung in ppp_exit_net

Status: upstream: reported on 2024/05/22 06:26
Reported-by: syzbot+1f82dbef70a30312f507@syzkaller.appspotmail.com
First crash: 31d, last: 31d
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: task hung in ppp_exit_net 1 25d 25d 0/3 upstream: reported on 2024/05/27 17:46
upstream INFO: task hung in ppp_exit_net (2) ppp 1 474d 474d 0/27 auto-obsoleted due to no activity on 2023/06/04 05:29
upstream INFO: task hung in ppp_exit_net (3) ppp 1 311d 311d 0/27 auto-obsoleted due to no activity on 2023/11/13 21:08
upstream INFO: task hung in ppp_exit_net (4) ppp 68 1d11h 9d00h 0/27 upstream: reported on 2024/06/13 09:12
upstream INFO: task hung in ppp_exit_net ppp 1 723d 723d 0/27 auto-closed as invalid on 2022/09/27 15:01

Sample crash report:
INFO: task kworker/u4:4:102 blocked for more than 143 seconds.
      Not tainted 6.1.91-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:4    state:D stack:20416 pid:102   ppid:2      flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6693
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6b9/0xd80 kernel/locking/mutex.c:747
 ppp_exit_net+0xe0/0x3b0 drivers/net/ppp/ppp_generic.c:1129
 ops_exit_list net/core/net_namespace.c:172 [inline]
 cleanup_net+0x6ce/0xb60 net/core/net_namespace.c:604
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
INFO: task syz-executor.0:4823 blocked for more than 143 seconds.
      Not tainted 6.1.91-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:27320 pid:4823  ppid:3573   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/22 06:25 linux-6.1.y 4078fa637fcd 1014eca7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in ppp_exit_net
* Struck through repros no longer work on HEAD.