syzbot


INFO: task hung in lock_sock_nested (3)
Status: fixed on 2020/11/16 12:12
Reported-by: syzbot+fcf8ca5817d6e92c6567@syzkaller.appspotmail.com
Fix commit: d9fb8c507d42 mptcp: fix infinite loop on recvmsg()/worker() race.
First crash: 396d, last: 380d

Cause bisection: introduced by (bisect log) :
commit ab174ad8ef76276cadfdae98731d31797d265927
Author: Paolo Abeni <pabeni@redhat.com>
Date: Mon Sep 14 08:01:12 2020 +0000

  mptcp: move ooo skbs into msk out of order queue.

Crash: INFO: task hung in synchronize_rcu (log)
Repro: C syz .config
similar bugs (12):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in lock_sock_nested (2) C done 418 592d 605d 17/22 fixed on 2020/04/15 17:19
upstream INFO: task hung in lock_sock_nested C 2593 609d 1409d 0/22 closed as dup on 2017/12/23 20:15
android-44 INFO: task hung in lock_sock_nested (2) 4 691d 787d 0/2 auto-closed as invalid on 2020/03/27 01:37
android-49 INFO: task hung in lock_sock_nested (2) 2 770d 889d 0/3 auto-closed as invalid on 2020/01/08 15:18
linux-4.14 INFO: task hung in lock_sock_nested 1 712d 712d 0/1 auto-closed as invalid on 2020/03/06 15:38
linux-4.14 INFO: task hung in lock_sock_nested (2) 1 449d 449d 0/1 auto-closed as invalid on 2020/11/24 03:07
android-44 INFO: task hung in lock_sock_nested C 82 1329d 1331d 0/2 closed as invalid on 2019/03/08 00:11
upstream INFO: task can't die in __lock_sock C done 870 20d 65d 0/22 upstream: reported C repro on 2021/08/15 16:47
upstream INFO: task hung in lock_sock_nested (4) C done 6 275d 321d 21/22 fixed on 2021/03/10 01:48
android-49 INFO: task hung in lock_sock_nested C 101 969d 1331d 0/3 closed as invalid on 2019/03/08 00:11
android-414 INFO: task hung in lock_sock_nested 65 735d 920d 0/1 auto-closed as invalid on 2020/02/12 04:11
linux-4.19 INFO: task hung in lock_sock_nested 1 528d 528d 0/1 auto-closed as invalid on 2020/09/05 19:53
Patch testing requests:
Created Duration User Patch Repo Result
2020/10/05 20:23 18m pabeni@redhat.com patch net-next OK
2020/10/05 13:17 13m pabeni@redhat.com patch net-next report log

Sample crash report:

Crashes (5):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-net-kasan-gce 2020/10/03 20:41 net-next 678cdd496708 2653fa43 .config log report syz C
ci-upstream-net-kasan-gce 2020/10/02 01:22 net-next 87d5034d0758 9602ddf4 .config log report syz C
ci-upstream-kasan-gce-root 2020/09/23 07:38 upstream eff48ddeab78 3e8f6c27 .config log report info
ci-upstream-net-kasan-gce 2020/09/24 03:02 net-next 1a26e88d534b 287cd75a .config log report info
ci-upstream-net-kasan-gce 2020/09/18 10:34 net-next 529d1fdf9719 38962c8b .config log report info