From: syzbot <syzbot+1e6138e3196ac80e99b8@syzkaller.appspotmail.com>
To: andrew.hendry@gmail.com, davem@davemloft.net, kuba@kernel.org,
linux-kernel@vger.kernel.org, linux-x25@vger.kernel.org,
netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com,
tanxin.ctf@gmail.com, xiyuyang19@fudan.edu.cn,
yuehaibing@huawei.com
Subject: possible deadlock in x25_disconnect
Date: Fri, 25 Sep 2020 01:48:16 -0700 [thread overview]
Message-ID: <000000000000b9cf7105b01f60a5@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: 77972b55 Revert "ravb: Fixed to be able to unload modules"
git tree: net
console output: https://syzkaller.appspot.com/x/log.txt?x=110cf809900000
kernel config: https://syzkaller.appspot.com/x/.config?x=5f4c828c9e3cef97
dashboard link: https://syzkaller.appspot.com/bug?extid=1e6138e3196ac80e99b8
compiler: gcc (GCC) 10.1.0-syz 20200507
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+1e6138e3196ac80e99b8@syzkaller.appspotmail.com
============================================
WARNING: possible recursive locking detected
5.9.0-rc6-syzkaller #0 Not tainted
--------------------------------------------
syz-executor.1/12065 is trying to acquire lock:
ffffffff8b2e7318 (x25_list_lock){++..}-{2:2}, at: x25_disconnect+0x279/0x3e0 net/x25/x25_subr.c:361
but task is already holding lock:
ffffffff8b2e7318 (x25_list_lock){++..}-{2:2}, at: x25_kill_by_device net/x25/af_x25.c:209 [inline]
ffffffff8b2e7318 (x25_list_lock){++..}-{2:2}, at: x25_device_event+0x1bf/0x300 net/x25/af_x25.c:247
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(x25_list_lock);
lock(x25_list_lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syz-executor.1/12065:
#0: ffffffff8b148f28 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x1a3/0xc40 net/core/dev_ioctl.c:510
#1: ffffffff8b2e7318 (x25_list_lock){++..}-{2:2}, at: x25_kill_by_device net/x25/af_x25.c:209 [inline]
#1: ffffffff8b2e7318 (x25_list_lock){++..}-{2:2}, at: x25_device_event+0x1bf/0x300 net/x25/af_x25.c:247
stack backtrace:
CPU: 0 PID: 12065 Comm: syz-executor.1 Not tainted 5.9.0-rc6-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+0x198/0x1fd lib/dump_stack.c:118
print_deadlock_bug kernel/locking/lockdep.c:2391 [inline]
check_deadlock kernel/locking/lockdep.c:2432 [inline]
validate_chain kernel/locking/lockdep.c:3202 [inline]
__lock_acquire.cold+0x148/0x3b0 kernel/locking/lockdep.c:4441
lock_acquire+0x1f3/0xaf0 kernel/locking/lockdep.c:5029
__raw_read_lock_bh include/linux/rwlock_api_smp.h:176 [inline]
_raw_read_lock_bh+0x32/0x40 kernel/locking/spinlock.c:247
x25_disconnect+0x279/0x3e0 net/x25/x25_subr.c:361
x25_kill_by_device net/x25/af_x25.c:213 [inline]
x25_device_event+0x27c/0x300 net/x25/af_x25.c:247
notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2033
call_netdevice_notifiers_extack net/core/dev.c:2045 [inline]
call_netdevice_notifiers net/core/dev.c:2059 [inline]
__dev_notify_flags+0x1da/0x2b0 net/core/dev.c:8325
dev_change_flags+0x100/0x160 net/core/dev.c:8361
dev_ifsioc+0x210/0xa70 net/core/dev_ioctl.c:265
dev_ioctl+0x1b1/0xc40 net/core/dev_ioctl.c:511
sock_do_ioctl+0x148/0x2d0 net/socket.c:1070
sock_ioctl+0x3b8/0x730 net/socket.c:1198
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45e179
Code: 3d b2 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 0b b2 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f623a794c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000015740 RCX: 000000000045e179
RDX: 0000000020000140 RSI: 0000000000008914 RDI: 0000000000000004
RBP: 000000000118cf80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c
R13: 00007ffc0abd13ff R14: 00007f623a7959c0 R15: 000000000118cf4c
---
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:[~2020-09-25 8:48 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=000000000000b9cf7105b01f60a5@google.com \
--to=syzbot+1e6138e3196ac80e99b8@syzkaller.appspotmail.com \
--cc=andrew.hendry@gmail.com \
--cc=davem@davemloft.net \
--cc=kuba@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-x25@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=syzkaller-bugs@googlegroups.com \
--cc=tanxin.ctf@gmail.com \
--cc=xiyuyang19@fudan.edu.cn \
--cc=yuehaibing@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).