Re: [syzbot] [mptcp?] WARNING in mptcp_check_listen_stop

[Paolo Abeni]

On Wed, 2023-12-13 at 10:53 -0800, syzbot wrote:
> syzbot has found a reproducer for the following issue on:
> 
> HEAD commit:    2513974cc3e1 Merge branch 'stmmac-bug-fixes'
> git tree:       net
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=116337fae80000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=b50bd31249191be8
> dashboard link: https://syzkaller.appspot.com/bug?extid=5a01c3a666e726bc8752
> compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1119061ee80000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=110ca006e80000

It looks like tcp_diag_destroy is closing the listener subflow, while
the mptcp stack is not expecting anyone to touch it while in listener
status. I guess we can relax the mptcp_check_listen_stop checks.

/P