syzbot


WARNING: bad unlock balance in rxrpc_do_sendmsg

Status: upstream: reported C repro on 2022/01/10 10:37
Reported-by: syzbot+7f0483225d0c94cb3441@syzkaller.appspotmail.com
First crash: 198d, last: 14h28m

Cause bisection: the issue happens on the oldest tested release (bisect log)
Crash: WARNING: bad unlock balance in rxrpc_do_sendmsg (log)
Repro: C syz .config

Sample crash report:
=====================================
WARNING: bad unlock balance detected!
5.19.0-rc5-syzkaller #0 Not tainted
-------------------------------------
syz-executor280/3608 is trying to release lock (&call->user_mutex) at:
[<ffffffff887ef3ae>] rxrpc_do_sendmsg+0xc0e/0x1350 net/rxrpc/sendmsg.c:754
but there are no more locks to release!

other info that might help us debug this:
no locks held by syz-executor280/3608.

stack backtrace:
CPU: 0 PID: 3608 Comm: syz-executor280 Not tainted 5.19.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_unlock_imbalance_bug include/trace/events/lock.h:69 [inline]
 __lock_release kernel/locking/lockdep.c:5332 [inline]
 lock_release.cold+0x49/0x4e kernel/locking/lockdep.c:5685
 __mutex_unlock_slowpath+0x99/0x5e0 kernel/locking/mutex.c:907
 rxrpc_do_sendmsg+0xc0e/0x1350 net/rxrpc/sendmsg.c:754
 rxrpc_sendmsg+0x429/0x640 net/rxrpc/af_rxrpc.c:561
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:734
 ____sys_sendmsg+0x6eb/0x810 net/socket.c:2488
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2542
 __sys_sendmsg net/socket.c:2571 [inline]
 __do_sys_sendmsg net/socket.c:2580 [inline]
 __se_sys_sendmsg net/socket.c:2578 [inline]
 __x64_sys_sendmsg+0x132/0x220 net/socket.c:2578
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7f6b7a064de9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 81 14 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6b7a017318 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f6b7a0ed3e8 RCX: 00007f6b7a064de9

Fix bisection attempts:
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-root 2022/06/15 13:35 upstream 018ab4fabddd 8bcc32a6 .config log report syz C
ci-upstream-kasan-gce-root 2022/05/16 13:14 upstream 42226c989789 8bcc32a6 .config log report syz C
ci-upstream-kasan-gce 2022/03/20 13:09 upstream 14702b3b2438 e4f103c4 .config log report syz C
ci-upstream-kasan-gce 2022/02/18 12:48 upstream 9195e5e0adbb e4f103c4 .config log report syz C
Crashes (14):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-selinux-root 2022/07/04 09:56 upstream 88084a3df167 1434eec0 .config log report syz C WARNING: bad unlock balance in rxrpc_do_sendmsg
ci-upstream-kasan-gce-root 2022/04/16 12:55 upstream 59250f8a7f3a 8bcc32a6 .config log report syz C WARNING: bad unlock balance in rxrpc_do_sendmsg
ci-upstream-kasan-gce 2021/12/26 18:06 upstream 438645193e59 e4f103c4 .config log report syz C WARNING: bad unlock balance in rxrpc_do_sendmsg
ci-upstream-bpf-kasan-gce 2021/12/26 18:51 bpf 819d11507f66 e4f103c4 .config log report syz C WARNING: bad unlock balance in rxrpc_do_sendmsg
ci-upstream-net-this-kasan-gce 2021/12/26 18:28 net e6007b85dfa2 e4f103c4 .config log report syz C WARNING: bad unlock balance in rxrpc_do_sendmsg
ci-upstream-bpf-next-kasan-gce 2021/12/26 18:27 bpf-next 4b443bc1785f e4f103c4 .config log report syz C WARNING: bad unlock balance in rxrpc_do_sendmsg
ci-upstream-net-kasan-gce 2021/12/26 18:26 net-next 7c63f26cb518 e4f103c4 .config log report syz C WARNING: bad unlock balance in rxrpc_do_sendmsg
ci-upstream-kasan-gce 2022/04/04 17:56 upstream 312310928417 5915c2cb .config log report info WARNING: bad unlock balance in rxrpc_do_sendmsg
ci-upstream-kasan-gce 2021/12/26 17:46 upstream 438645193e59 e4f103c4 .config log report info WARNING: bad unlock balance in rxrpc_do_sendmsg
ci-upstream-bpf-kasan-gce 2022/01/10 22:02 bpf d6d86830705f ddb0ab8c .config log report info WARNING: bad unlock balance in rxrpc_do_sendmsg
ci-upstream-bpf-next-kasan-gce 2022/01/19 12:22 bpf-next eaa266d83a37 0620189b .config log report info WARNING: bad unlock balance in rxrpc_do_sendmsg
ci-upstream-bpf-next-kasan-gce 2022/01/10 04:44 bpf-next 242db6ce976a 2ca0d385 .config log report info WARNING: bad unlock balance in rxrpc_do_sendmsg
ci-upstream-bpf-next-kasan-gce 2021/12/25 06:37 bpf-next 4b443bc1785f 6caa12e4 .config log report info WARNING: bad unlock balance in rxrpc_do_sendmsg
ci-upstream-bpf-next-kasan-gce 2021/12/18 08:31 bpf-next 4b443bc1785f 44068e19 .config log report info WARNING: bad unlock balance in rxrpc_do_sendmsg