syzbot


INFO: task hung in switchdev_deferred_process_work (2)

Status: upstream: reported on 2025/12/02 15:22
Reported-by: syzbot+4e23e13d1bb3927b03f0@syzkaller.appspotmail.com
First crash: 41d, last: 3d14h
Similar bugs (12)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: task hung in switchdev_deferred_process_work (2) 1 1 112d 112d 0/3 auto-obsoleted due to no activity on 2025/12/31 08:30
upstream INFO: task hung in switchdev_deferred_process_work (2) net 1 C inconclusive 1226 552d 1995d 26/29 fixed on 2024/07/09 19:14
linux-6.6 INFO: task hung in switchdev_deferred_process_work 1 1 173d 173d 0/2 auto-obsoleted due to no activity on 2025/10/31 04:22
upstream INFO: task hung in switchdev_deferred_process_work net 1 35 2285d 2822d 0/29 closed as invalid on 2019/10/23 07:26
upstream INFO: task hung in switchdev_deferred_process_work (3) net 1 C inconclusive 583 3d02h 522d 0/29 upstream: reported C repro on 2024/08/08 21:14
linux-5.15 INFO: task hung in switchdev_deferred_process_work (4) 1 2 24d 33d 0/3 upstream: reported on 2025/12/11 00:18
linux-5.15 INFO: task hung in switchdev_deferred_process_work 1 1 1006d 1006d 0/3 auto-obsoleted due to no activity on 2023/08/10 05:46
linux-4.19 INFO: task hung in switchdev_deferred_process_work 1 95 1058d 2136d 0/1 upstream: reported on 2020/03/08 04:06
linux-4.14 INFO: task hung in switchdev_deferred_process_work 1 1 1347d 1347d 0/1 auto-obsoleted due to no activity on 2022/09/03 16:45
linux-5.15 INFO: task hung in switchdev_deferred_process_work (2) 1 36 660d 732d 0/3 auto-obsoleted due to no activity on 2024/06/01 16:21
linux-5.15 INFO: task hung in switchdev_deferred_process_work (3) 1 8 444d 587d 0/3 auto-obsoleted due to no activity on 2025/02/02 03:46
linux-6.1 INFO: task hung in switchdev_deferred_process_work 1 8 551d 714d 0/3 auto-obsoleted due to no activity on 2024/10/18 09:59

Sample crash report:
INFO: task kworker/0:4:5802 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:4     state:D stack:25992 pid:5802  ppid:2      flags:0x00004000
Workqueue: events switchdev_deferred_process_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747
 switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/09 12:01 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in switchdev_deferred_process_work
2025/12/02 15:21 linux-6.6.y 4791134e4aeb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in switchdev_deferred_process_work
* Struck through repros no longer work on HEAD.