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: 271d, last: 6h42m
▶ ▼ Similar bugs (14)
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 343d 343d 0/3 auto-obsoleted due to no activity on 2025/12/31 08:30
linux-6.1 INFO: task hung in switchdev_deferred_process_work (3) 1 2 4d19h 102d 0/3 upstream: reported on 2026/05/20 16:07
linux-5.15 INFO: task hung in switchdev_deferred_process_work (5) 1 2 3d17h 95d 0/3 upstream: reported on 2026/05/27 14:28
upstream INFO: task hung in switchdev_deferred_process_work (2) net 1 syz, C inconclusive 1226 783d 2225d 26/29 fixed on 2024/07/09 19:14
linux-6.6 INFO: task hung in switchdev_deferred_process_work 1 1 404d 404d 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 2515d 3052d 0/29 closed as invalid on 2019/10/23 07:26
upstream INFO: task hung in switchdev_deferred_process_work (3) net 1 syz, C inconclusive 766 14m 752d 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 255d 263d 0/3 auto-obsoleted due to no activity on 2026/03/29 12:57
linux-5.15 INFO: task hung in switchdev_deferred_process_work 1 1 1237d 1237d 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 1289d 2367d 0/1 upstream: reported on 2020/03/08 04:06
linux-4.14 INFO: task hung in switchdev_deferred_process_work 1 1 1577d 1577d 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 890d 962d 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 675d 818d 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 782d 945d 0/3 auto-obsoleted due to no activity on 2024/10/18 09:59

Sample crash report:
INFO: task kworker/0:6:5819 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:6     state:D stack:21272 pid:5819  ppid:2      flags:0x00004000
Workqueue: events switchdev_deferred_process_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6701
 schedule+0xbd/0x170 kernel/sched/core.c:6775
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6834
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
 switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
 process_one_work kernel/workqueue.c:2657 [inline]
 process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734
 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815

Crashes (16):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/31 06:53 linux-6.6.y a4a971135a2f 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: task hung in switchdev_deferred_process_work
2026/08/30 07:35 linux-6.6.y a4a971135a2f 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: task hung in switchdev_deferred_process_work
2026/08/16 19:42 linux-6.6.y d27334b2888c 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: task hung in switchdev_deferred_process_work
2026/08/13 20:51 linux-6.6.y d27334b2888c b13552fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: task hung in switchdev_deferred_process_work
2026/08/09 23:32 linux-6.6.y d27334b2888c 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: task hung in switchdev_deferred_process_work
2026/07/12 05:01 linux-6.6.y da47cbc25466 d78ea535 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in switchdev_deferred_process_work
2026/05/20 06:33 linux-6.6.y eac8889a3a1c 0909d65f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in switchdev_deferred_process_work
2026/05/20 04:57 linux-6.6.y eac8889a3a1c 0909d65f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in switchdev_deferred_process_work
2026/04/18 20:13 linux-6.6.y 9760bf04666d 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in switchdev_deferred_process_work
2026/04/13 03:20 linux-6.6.y 8cee53b8eaeb 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in switchdev_deferred_process_work
2026/04/02 05:48 linux-6.6.y c09fbcd31ae6 0cb124d5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in switchdev_deferred_process_work
2026/03/31 05:00 linux-6.6.y c09fbcd31ae6 d0af506e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: task hung in switchdev_deferred_process_work
2026/01/23 05:50 linux-6.6.y cbb31f77b879 82c9c083 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in switchdev_deferred_process_work
2026/01/19 09:51 linux-6.6.y cbb31f77b879 a9fc5226 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: task hung in switchdev_deferred_process_work
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.