Subject: Re: KASAN: use-after-free Read in fib6_ifup (2)

From: Ido Schimmel <[email-masked]>
Date: Sat, 20 Jan 2018 14:54:51 +0200

On Thu, Jan 18, 2018 at 09:58:01PM -0800, syzbot wrote:
> Hello,
> 
> syzbot hit the following crash on net-next commit
> 564737f981fb4b4b3266901508bb9b90d9d43de8
> 
> So far this crash happened 18 times on mmots, net-next.
> C reproducer is attached.
> syzkaller reproducer is attached.
> Raw console output is attached.
> compiler: gcc (GCC) 7.1.1 20170620
> .config is attached.

[...]

> syzbot will keep track of this bug report.
> If you forgot to add the Reported-by tag, once the fix for this bug is
> merged
> into any tree, please reply to this email with:
> #syz fix: exact-commit-title

The reproducer configures a default source-specific route which triggers
a bug that is now fixed in net-next, so:

#syz fix: ipv6: don't let tb6_root node share routes with other node

Verified it on my machine using the reproducer attached by the bot.