INFO: rcu detected stall in netlink_sendmsg (3)
Status: internal: reported C repro on 2019/12/20 02:24
Fix commit: d9e15a27 pkt_sched: fq: do not accept silly TCA_FQ_QUANTUM
Patched on: [ci-qemu-upstream ci-qemu-upstream-386 ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-leak ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-kcsan-gce ci2-upstream-usb], missing on: [ci-upstream-kmsan-gce]
First crash: 59d, last: 5d23h

Cause bisection: the bug happens on the oldest tested release
Crash: INFO: rcu detected stall in corrupted (log)
Repro: C syz .config
similar bugs (3):
Kernel Title Repro Bisected Count Last Reported Patched Status
upstream INFO: rcu detected stall in netlink_sendmsg (2) C cause 11 155d 161d 14/16 fixed on 2019/10/09 10:54
linux-4.19 INFO: rcu detected stall in netlink_sendmsg C fix 3 153d 158d 1/1 fixed on 2019/12/10 03:52
upstream INFO: rcu detected stall in netlink_sendmsg syz 83 364d 420d 12/16 fixed on 2019/03/06 07:43

Sample crash report:

Crashes (6):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro Maintainers
ci-upstream-kasan-gce-root 2019/12/21 09:15 upstream 6398b9fc bc586918 .config log report syz C,,,,,
ci-upstream-net-this-kasan-gce 2019/12/20 02:23 net 6fa9a115 36650b4b .config log report syz C,,,,,
ci-upstream-kasan-gce-selinux-root 2020/01/26 16:14 upstream 2821e26f dd56146d .config log report,,,,,,,,
ci-upstream-kasan-gce 2020/01/22 10:27 upstream d96d875e 8eda0b95 .config log report,,,,,,,
ci-upstream-net-kasan-gce 2020/02/11 09:48 net-next fdfa3a67 084454ae .config log report,,,,,,,,
ci-upstream-net-kasan-gce 2020/02/03 10:31 net-next 9f68e365 93e5e335 .config log report,,,,,,,,