From: Cong Wang <xiyou.wangc...@gmail.com>
Date: Tue, 11 Dec 2018 21:43:51 -0800
> tipc_wait_for_cond() drops socket lock before going to sleep,
> but tsk->group could be freed right after that release_sock().
> So we have to re-check and reload tsk->group after it wakes up.
>
> After this patch, tipc_wait_for_cond() returns -ERESTARTSYS when
> tsk->group is NULL, instead of continuing with the assumption of
> a non-NULL tsk->group.
>
> (It looks like 'dsts' should be re-checked and reloaded too, but
> it is a different bug.)
>
> Similar for tipc_send_group_unicast() and tipc_send_group_anycast().
>
> Reported-by: syzbot+10a9db47c3a0e13eb...@syzkaller.appspotmail.com
> Fixes: b7d42635517f ("tipc: introduce flow control for group broadcast
> messages")
> Fixes: ee106d7f942d ("tipc: introduce group anycast messaging")
> Fixes: 27bd9ec027f3 ("tipc: introduce group unicast messaging")
> Cc: Ying Xue <ying....@windriver.com>
> Cc: Jon Maloy <jon.ma...@ericsson.com>
> Signed-off-by: Cong Wang <xiyou.wangc...@gmail.com>
Applied and queued up for -stable, thanks Cong.
