WARNING in aa_sock_msg_perm

[Tetsuo Handa]

On 2019/08/12 21:30, syzbot wrote:
> Hello,
> 
> syzbot found the following crash on:
> 
> HEAD commit:    fcc32a21 liquidio: Use pcie_flr() instead of reimplementin..
> git tree:       net-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=11233726600000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=d4cf1ffb87d590d7
> dashboard link: https://syzkaller.appspot.com/bug?extid=cda1ac91660a61b51495
> compiler:       gcc (GCC) 9.0.0 20181231 (experimental)

> ------------[ cut here ]------------
> AppArmor WARN aa_sock_msg_perm: ((!sock)):

This is not AppArmor's bug. LSM modules expect that "struct socket" is not NULL.
For some reason, peer->local->socket became NULL. Thus, suspecting rxrpc's bug.

>  rxrpc_send_keepalive+0x1ff/0x940 net/rxrpc/output.c:656