INFO: task hung in ret_from_fork

Status: premoderation: reported on 2026/07/27 18:00
Reported-by: syzbot+a505f23a18bf9e9417f8@syzkaller.appspotmail.com
First crash: 11d, last: 11d
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in ret_from_fork (3) serial 1 1 1002d 1002d 0/29 auto-obsoleted due to no activity on 2024/02/08 01:02
upstream INFO: task hung in ret_from_fork (2) fs 1 1 2106d 2106d 0/29 auto-closed as invalid on 2020/12/31 10:28
upstream INFO: task hung in ret_from_fork fs 1 4 2920d 2927d 0/29 auto-closed as invalid on 2019/02/22 10:29
upstream INFO: task hung in ret_from_fork (4) prio:high kernel 1 syz, C error error 30 4d20h 159d 0/29 upstream: reported C repro on 2026/03/01 18:35

Sample crash report:
INFO: task kworker/u8:4:310 blocked for more than 134 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:4    state:D
 stack:0     pid:310   tgid:310   ppid:2      flags:0x00004000
Workqueue: ipv6_addrconf addrconf_dad_work

Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:6060 [inline]
 __schedule+0x1496/0x20b0 kernel/sched/core.c:7880
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
INFO: task kworker/u8:6:21772 blocked for more than 142 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:6    state:D
 stack:0     pid:21772 tgid:21772 ppid:2      flags:0x00004000
Workqueue: events_unbound linkwatch_event

Call Trace:

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/27 17:59 android16-6.12 a12ab5a23a35 aae9036b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in ret_from_fork
* Struck through repros no longer work on HEAD.