From: syzbot <syzbot+e56606435b7bfeea8cf5@syzkaller.appspotmail.com>
To: davem@davemloft.net, fw@strlen.de, kuba@kernel.org,
linux-kernel@vger.kernel.org, mathew.j.martineau@linux.intel.com,
matthieu.baerts@tessares.net, mptcp@lists.01.org,
netdev@vger.kernel.org, pabeni@redhat.com,
syzkaller-bugs@googlegroups.com
Subject: WARNING: bad unlock balance in mptcp_poll
Date: Sat, 11 Apr 2020 09:51:14 -0700 [thread overview]
Message-ID: <000000000000758fcf05a306a8bf@google.com> (raw)
Hello,
syzbot found the following crash on:
HEAD commit: ae46d2aa mm/gup: Let __get_user_pages_locked() return -EIN..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14fef69fe00000
kernel config: https://syzkaller.appspot.com/x/.config?x=ca75979eeebf06c2
dashboard link: https://syzkaller.appspot.com/bug?extid=e56606435b7bfeea8cf5
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=111ccd2be00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=162b0a77e00000
The bug was bisected to:
commit 59832e246515ab6a4f5aa878073e6f415aa35166
Author: Florian Westphal <fw@strlen.de>
Date: Thu Apr 2 11:44:52 2020 +0000
mptcp: subflow: check parent mptcp socket on subflow state change
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=14c1f69fe00000
final crash: https://syzkaller.appspot.com/x/report.txt?x=16c1f69fe00000
console output: https://syzkaller.appspot.com/x/log.txt?x=12c1f69fe00000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+e56606435b7bfeea8cf5@syzkaller.appspotmail.com
Fixes: 59832e246515 ("mptcp: subflow: check parent mptcp socket on subflow state change")
=====================================
WARNING: bad unlock balance detected!
5.6.0-syzkaller #0 Not tainted
-------------------------------------
syz-executor473/7733 is trying to release lock (sk_lock-AF_INET6) at:
[<ffffffff87c51839>] mptcp_poll+0xb9/0x530 net/mptcp/protocol.c:1856
but there are no more locks to release!
other info that might help us debug this:
1 lock held by syz-executor473/7733:
#0: ffff88808fe2f0a0 (slock-AF_INET6){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:358 [inline]
#0: ffff88808fe2f0a0 (slock-AF_INET6){+...}-{2:2}, at: release_sock+0x1b/0x1b0 net/core/sock.c:2974
stack backtrace:
CPU: 0 PID: 7733 Comm: syz-executor473 Not tainted 5.6.0-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:4633 [inline]
lock_release+0x586/0x800 kernel/locking/lockdep.c:4941
sock_release_ownership include/net/sock.h:1539 [inline]
release_sock+0x177/0x1b0 net/core/sock.c:2984
mptcp_poll+0xb9/0x530 net/mptcp/protocol.c:1856
sock_poll+0x15c/0x470 net/socket.c:1271
vfs_poll include/linux/poll.h:90 [inline]
do_pollfd fs/select.c:859 [inline]
do_poll fs/select.c:907 [inline]
do_sys_poll+0x63c/0xdd0 fs/select.c:1001
__do_sys_ppoll fs/select.c:1101 [inline]
__se_sys_ppoll fs/select.c:1081 [inline]
__x64_sys_ppoll+0x210/0x280 fs/select.c:1081
do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x441219
Code: e8 fc ab 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 9b 09 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff9deb18e8 EFLAGS: 00000246 ORIG_RAX: 000000000000010f
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441219
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000020000080
RBP: 000000000000f233 R08: 3f00000000000000 R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402040
R13: 00000000004020d0 R14: 0000000000000000 R15: 0000000000000000
---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches
next reply other threads:[~2020-04-11 16:51 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-11 16:51 syzbot [this message]
2020-04-11 19:05 ` [PATCH net] mptcp: fix double-unlock in mptcp_poll Florian Westphal
2020-04-13 4:05 ` David Miller
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