From: syzbot <syzbot+c18d9ae8897308206c1d@syzkaller.appspotmail.com>
To: davem@davemloft.net, dsahern@kernel.org, kuba@kernel.org,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
syzkaller-bugs@googlegroups.com, yoshfuji@linux-ipv6.org
Subject: [syzbot] possible deadlock in ipv6_sock_ac_close
Date: Wed, 31 Mar 2021 08:37:23 -0700 [thread overview]
Message-ID: <000000000000246d0105bed6e42d@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: 37f368d8 lan743x: remove redundant intializations of point..
git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=13fe28ced00000
kernel config: https://syzkaller.appspot.com/x/.config?x=7eff0f22b8563a5f
dashboard link: https://syzkaller.appspot.com/bug?extid=c18d9ae8897308206c1d
Unfortunately, I don't have any reproducer for this issue yet.
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c18d9ae8897308206c1d@syzkaller.appspotmail.com
======================================================
WARNING: possible circular locking dependency detected
5.12.0-rc4-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.3/17484 is trying to acquire lock:
ffffffff8d66d328 (rtnl_mutex){+.+.}-{3:3}, at: ipv6_sock_ac_close+0xd5/0x110 net/ipv6/anycast.c:219
but task is already holding lock:
ffff88806c808120 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1600 [inline]
ffff88806c808120 (sk_lock-AF_INET6){+.+.}-{0:0}, at: mptcp6_release+0x57/0x130 net/mptcp/protocol.c:3530
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (sk_lock-AF_INET6){+.+.}-{0:0}:
lock_sock_nested+0xca/0x120 net/core/sock.c:3071
lock_sock include/net/sock.h:1600 [inline]
do_ipv6_setsockopt.constprop.0+0x31f/0x4220 net/ipv6/ipv6_sockglue.c:418
ipv6_setsockopt+0xd6/0x180 net/ipv6/ipv6_sockglue.c:1003
__sys_setsockopt+0x2db/0x610 net/socket.c:2117
__do_sys_setsockopt net/socket.c:2128 [inline]
__se_sys_setsockopt net/socket.c:2125 [inline]
__x64_sys_setsockopt+0xba/0x150 net/socket.c:2125
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #0 (rtnl_mutex){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:2936 [inline]
check_prevs_add kernel/locking/lockdep.c:3059 [inline]
validate_chain kernel/locking/lockdep.c:3674 [inline]
__lock_acquire+0x2b14/0x54c0 kernel/locking/lockdep.c:4900
lock_acquire kernel/locking/lockdep.c:5510 [inline]
lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5475
__mutex_lock_common kernel/locking/mutex.c:949 [inline]
__mutex_lock+0x139/0x1120 kernel/locking/mutex.c:1096
ipv6_sock_ac_close+0xd5/0x110 net/ipv6/anycast.c:219
mptcp6_release+0xc1/0x130 net/mptcp/protocol.c:3539
__sock_release+0xcd/0x280 net/socket.c:599
sock_close+0x18/0x20 net/socket.c:1258
__fput+0x288/0x920 fs/file_table.c:280
task_work_run+0xdd/0x1a0 kernel/task_work.c:140
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:208
__syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301
entry_SYSCALL_64_after_hwframe+0x44/0xae
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(sk_lock-AF_INET6);
lock(rtnl_mutex);
lock(sk_lock-AF_INET6);
lock(rtnl_mutex);
*** DEADLOCK ***
2 locks held by syz-executor.3/17484:
#0: ffff888062f3a6d0 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:775 [inline]
#0: ffff888062f3a6d0 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: __sock_release+0x86/0x280 net/socket.c:598
#1: ffff88806c808120 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1600 [inline]
#1: ffff88806c808120 (sk_lock-AF_INET6){+.+.}-{0:0}, at: mptcp6_release+0x57/0x130 net/mptcp/protocol.c:3530
stack backtrace:
CPU: 0 PID: 17484 Comm: syz-executor.3 Not tainted 5.12.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0x141/0x1d7 lib/dump_stack.c:120
check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2127
check_prev_add kernel/locking/lockdep.c:2936 [inline]
check_prevs_add kernel/locking/lockdep.c:3059 [inline]
validate_chain kernel/locking/lockdep.c:3674 [inline]
__lock_acquire+0x2b14/0x54c0 kernel/locking/lockdep.c:4900
lock_acquire kernel/locking/lockdep.c:5510 [inline]
lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5475
__mutex_lock_common kernel/locking/mutex.c:949 [inline]
__mutex_lock+0x139/0x1120 kernel/locking/mutex.c:1096
ipv6_sock_ac_close+0xd5/0x110 net/ipv6/anycast.c:219
mptcp6_release+0xc1/0x130 net/mptcp/protocol.c:3539
__sock_release+0xcd/0x280 net/socket.c:599
sock_close+0x18/0x20 net/socket.c:1258
__fput+0x288/0x920 fs/file_table.c:280
task_work_run+0xdd/0x1a0 kernel/task_work.c:140
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:208
__syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x41926b
Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44
RSP: 002b:00007fffdbb1c900 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 000000000041926b
RDX: 0000000000000000 RSI: 000000000d1327a1 RDI: 0000000000000003
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000001b32727cec
R10: 0000000000000000 R11: 0000000000000293 R12: 000000000056c9e0
R13: 000000000056c9e0 R14: 000000000056bf60 R15: 000000000005bd25
---
This report 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 issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
reply other threads:[~2021-03-31 15:37 UTC|newest]
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