Re: [syzbot] [net?] WARNING in default_device_exit_batch (4)

From: syzbot
Date: Thu Mar 02 2023 - 05:16:59 EST


syzbot has found a reproducer for the following issue on:

HEAD commit: 5b7c4cabbb65 Merge tag 'net-next-6.3' of git://git.kernel...
git tree: net-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=12e7db64c80000
kernel config: https://syzkaller.appspot.com/x/.config?x=c74c134cc415a89b
dashboard link: https://syzkaller.appspot.com/bug?extid=9dfc3f3348729cc82277
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13158898c80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11c52674c80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/65932a118570/disk-5b7c4cab.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8de67fb8c522/vmlinux-5b7c4cab.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2b90e329d792/bzImage-5b7c4cab.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9dfc3f3348729cc82277@xxxxxxxxxxxxxxxxxxxxxxxxx

bond7 (unregistering): Released all slaves
------------[ cut here ]------------
WARNING: CPU: 1 PID: 56 at net/core/dev.c:10867 unregister_netdevice_many_notify+0x14cf/0x19f0 net/core/dev.c:10867
Modules linked in:
CPU: 1 PID: 56 Comm: kworker/u4:4 Not tainted 6.2.0-syzkaller-05251-g5b7c4cabbb65 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023
Workqueue: netns cleanup_net
RIP: 0010:unregister_netdevice_many_notify+0x14cf/0x19f0 net/core/dev.c:10867
Code: af 1a 00 00 48 c7 c6 00 1c 5c 8b 48 c7 c7 40 1c 5c 8b c6 05 28 d4 4c 06 01 e8 5d 45 37 f9 0f 0b e9 01 f9 ff ff e8 f1 c8 6f f9 <0f> 0b e9 d8 f8 ff ff e8 85 66 c1 f9 e9 11 ed ff ff 4c 89 ef e8 d8
RSP: 0018:ffffc90001577a38 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 000000007db3f601 RCX: 0000000000000000
RDX: ffff888017d61d40 RSI: ffffffff8814e53f RDI: 0000000000000001
RBP: ffff88807bc46100 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88807bc46100 R14: ffff88802ab70000 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffcb678e960 CR3: 00000000768f2000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
unregister_netdevice_many net/core/dev.c:10897 [inline]
default_device_exit_batch+0x451/0x5b0 net/core/dev.c:11350
ops_exit_list+0x125/0x170 net/core/net_namespace.c:174
cleanup_net+0x4ee/0xb10 net/core/net_namespace.c:613
process_one_work+0x9bf/0x1820 kernel/workqueue.c:2390
worker_thread+0x669/0x1090 kernel/workqueue.c:2537
kthread+0x2e8/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
</TASK>