INFO: task hung in netlink_dump (2)

Status: upstream: reported on 2026/04/18 17:22
Reported-by: syzbot+cd848ab7597dc0b26315@syzkaller.appspotmail.com
First crash: 115d, last: 12h24m
▶ ▼ Similar bugs (13)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in netlink_dump (5) net 1 123 688d 748d 0/29 auto-obsoleted due to no activity on 2024/12/01 23:22
upstream INFO: task hung in netlink_dump (2) net 1 2 1628d 1629d 0/29 auto-closed as invalid on 2022/05/26 21:32
upstream INFO: task hung in netlink_dump (7) net 1 1 310d 310d 0/29 auto-obsoleted due to no activity on 2026/01/04 01:58
upstream INFO: task hung in netlink_dump net 1 1 1799d 1799d 0/29 auto-closed as invalid on 2021/12/07 11:04
linux-6.1 INFO: task hung in netlink_dump 1 3 894d 912d 0/3 auto-obsoleted due to no activity on 2024/06/09 02:46
upstream INFO: task hung in netlink_dump (3) net 1 78 912d 1070d 0/29 closed as invalid on 2024/02/12 15:10
linux-5.15 INFO: task hung in netlink_dump 1 3 786d 792d 0/3 auto-obsoleted due to no activity on 2024/09/25 04:53
linux-6.1 INFO: task hung in netlink_dump (3) 1 1 622d 622d 0/3 auto-obsoleted due to no activity on 2025/03/08 04:08
linux-6.1 INFO: task hung in netlink_dump (4) 1 2 455d 494d 0/3 auto-obsoleted due to no activity on 2025/08/22 04:23
linux-6.1 INFO: task hung in netlink_dump (2) 1 1 790d 790d 0/3 auto-obsoleted due to no activity on 2024/09/21 04:37
upstream INFO: task hung in netlink_dump (6) net 1 1 569d 569d 0/29 auto-obsoleted due to no activity on 2025/04/20 06:11
linux-6.6 INFO: task hung in netlink_dump 1 1 229d 229d 0/2 auto-obsoleted due to no activity on 2026/04/05 05:43
upstream INFO: task hung in netlink_dump (4) net 1 72 856d 896d 25/29 fixed on 2024/04/12 18:02

Sample crash report:
INFO: task dhcpcd:5438 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:dhcpcd          state:D stack:20968 pid:5438  ppid:5437   flags:0x00004002
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
 netlink_dump+0x77c/0xec0 net/netlink/af_netlink.c:2268
 netlink_recvmsg+0x693/0xe60 net/netlink/af_netlink.c:1981

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/12 03:10 linux-6.6.y d27334b2888c f8d35649 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: task hung in netlink_dump
2026/07/17 08:46 linux-6.6.y da47cbc25466 7f27c57a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in netlink_dump
2026/07/12 02:37 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 netlink_dump
2026/04/29 00:35 linux-6.6.y 142cd8382222 95008c03 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in netlink_dump
2026/04/18 18:59 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 netlink_dump
2026/04/18 17:21 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 netlink_dump
* Struck through repros no longer work on HEAD.