From: David Miller <davem@davemloft.net>
To: weiwan@google.com
Cc: netdev@vger.kernel.org, edumazet@google.com, dsahern@gmail.com,
kafai@fb.com
Subject: Re: [PATCH net] ipv6: use fib6_info_hold_safe() when necessary
Date: Mon, 23 Jul 2018 11:19:55 -0700 (PDT) [thread overview]
Message-ID: <20180723.111955.865372914094677781.davem@davemloft.net> (raw)
In-Reply-To: <20180722035632.136090-1-tracywwnj@gmail.com>
From: Wei Wang <weiwan@google.com>
Date: Sat, 21 Jul 2018 20:56:32 -0700
> From: Wei Wang <weiwan@google.com>
>
> In the code path where only rcu read lock is held, e.g. in the route
> lookup code path, it is not safe to directly call fib6_info_hold()
> because the fib6_info may already have been deleted but still exists
> in the rcu grace period. Holding reference to it could cause double
> free and crash the kernel.
>
> This patch adds a new function fib6_info_hold_safe() and replace
> fib6_info_hold() in all necessary places.
>
> Syzbot reported 3 crash traces because of this. One of them is:
...
> Fixes: 93531c674315 (net/ipv6: separate handling of FIB entries from dst based routes)
> Reported-by: syzbot+902e2a1bcd4f7808cef5@syzkaller.appspotmail.com
> Reported-by: syzbot+8ae62d67f647abeeceb9@syzkaller.appspotmail.com
> Reported-by: syzbot+3f08feb14086930677d0@syzkaller.appspotmail.com
> Signed-off-by: Wei Wang <weiwan@google.com>
> Acked-by: Eric Dumazet <edumazet@google.com>
Applied, thank you.
next prev parent reply other threads:[~2018-07-23 19:22 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-22 3:56 [PATCH net] ipv6: use fib6_info_hold_safe() when necessary Wei Wang
2018-07-23 14:28 ` David Ahern
2018-07-23 18:19 ` David Miller [this message]
2018-07-23 18:25 ` Martin KaFai Lau
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180723.111955.865372914094677781.davem@davemloft.net \
--to=davem@davemloft.net \
--cc=dsahern@gmail.com \
--cc=edumazet@google.com \
--cc=kafai@fb.com \
--cc=netdev@vger.kernel.org \
--cc=weiwan@google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox