Re: BUG: stack guard page was hit in unwind_next_frame

Cong Wang
2020-05-05T01:06:27Z

On Mon, May 4, 2020 at 12:08 PM Josh Poimboeuf <jpoimboe@redhat.com> wrote:
>
> On Sat, May 02, 2020 at 11:36:11PM -0700, syzbot wrote:
> > Hello,
> >
> > syzbot found the following crash on:
> >
> > HEAD commit: 8999dc89 net/x25: Fix null-ptr-deref in x25_disconnect
> > git tree: net
> > console output: https://syzkaller.appspot.com/x/log.txt?x=16004440100000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=b7a70e992f2f9b68
> > dashboard link: https://syzkaller.appspot.com/bug?extid=e73ceacfd8560cc8a3ca
> > compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> >
> > Unfortunately, I don't have any reproducer for this crash yet.
> >
> > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > Reported-by: syzbot+e73ceacfd8560cc8a3ca@syzkaller.appspotmail.com
>
> Infinite loop in network code.

It is not a loop, it is an unbound recursion where netdev events
trigger between bond master and slave back and forth.

Let me see how this can be fixed properly.

Thanks!