WARNING: bad unlock balance in mptcp

WARNING: bad unlock balance in mptcp_listen
Status: closed as dup on 2020/04/12 08:32
Reported-by: syzbot+ffec3741d41140477097@syzkaller.appspotmail.com
First crash: 524d, last: 522d

Duplicate of (1):
Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported
WARNING: bad unlock balance in mptcp_poll	C	done		10	521d	524d

Sample crash report:

=====================================
WARNING: bad unlock balance detected!
5.7.0-rc1-syzkaller #0 Not tainted
-------------------------------------
syz-executor.4/11305 is trying to release lock (sk_lock-AF_INET6) at:
[<ffffffff87cb6063>] mptcp_listen+0x1c3/0x2e0 net/mptcp/protocol.c:1783
but there are no more locks to release!

other info that might help us debug this:
1 lock held by syz-executor.4/11305:
 #0: ffff88803f6aa6a0 (slock-AF_INET6){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:358 [inline]
 #0: ffff88803f6aa6a0 (slock-AF_INET6){+.-.}-{2:2}, at: release_sock+0x1b/0x1b0 net/core/sock.c:2974

stack backtrace:
CPU: 0 PID: 11305 Comm: syz-executor.4 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x188/0x20d lib/dump_stack.c:118
 __lock_release kernel/locking/lockdep.c:4644 [inline]
 lock_release+0x586/0x800 kernel/locking/lockdep.c:4952
 sock_release_ownership include/net/sock.h:1539 [inline]
 release_sock+0x177/0x1b0 net/core/sock.c:2984
 mptcp_listen+0x1c3/0x2e0 net/mptcp/protocol.c:1783
 __sys_listen+0x17d/0x250 net/socket.c:1696
 __do_sys_listen net/socket.c:1705 [inline]
 __se_sys_listen net/socket.c:1703 [inline]
 __x64_sys_listen+0x50/0x70 net/socket.c:1703
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x45c889
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f16210dec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000032
RAX: ffffffffffffffda RBX: 00007f16210df6d4 RCX: 000000000045c889
RDX: 0000000000000000 RSI: 00000000fec00000 RDI: 0000000000000003
RBP: 000000000076bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000714 R14: 00000000004c9e55 R15: 000000000076bfac

Crashes (2):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci-upstream-kasan-gce	2020/04/13 17:24	upstream	8f3d9f354286	17a986e5	.config	log	report
ci-upstream-kasan-gce-selinux-root	2020/04/11 19:30	upstream	5b8b9d0c6d0e	a8c6a3f8	.config	log	report