From: Ido Schimmel <idosch@nvidia.com>
To: Kuniyuki Iwashima <kuniyu@google.com>
Cc: David Ahern <dsahern@kernel.org>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Simon Horman <horms@kernel.org>,
Kuniyuki Iwashima <kuni1840@gmail.com>,
netdev@vger.kernel.org,
syzbot+01f005f9c6387ca6f6dd@syzkaller.appspotmail.com
Subject: Re: [PATCH v1 net] ipv6: Fix null-ptr-deref in fib6_mtu().
Date: Mon, 4 May 2026 19:43:25 +0300 [thread overview]
Message-ID: <20260504164325.GA393023@shredder> (raw)
In-Reply-To: <20260504064316.3820775-1-kuniyu@google.com>
On Mon, May 04, 2026 at 06:43:13AM +0000, Kuniyuki Iwashima wrote:
> syzbot reported null-ptr-deref in fib6_mtu(). [0]
>
> When res->f6i->fib6_pmtu is 0 in fib6_mtu(), it fetches MTU from
> __in6_dev_get(nh->fib_nh_dev)->cnf.mtu6.
>
> However, __in6_dev_get() could return NULL when the device is
> being unregistered.
>
> Let's return 0 MTU if __in6_dev_get() returns NULL in fib6_mtu().
[...]
> Fixes: dcd1f572954f ("net/ipv6: Remove fib6_idev")
> Reported-by: syzbot+01f005f9c6387ca6f6dd@syzkaller.appspotmail.com
> Closes: https://lore.kernel.org/netdev/69f83f22.170a0220.13cc2.0004.GAE@google.com/
> Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
next prev parent reply other threads:[~2026-05-04 16:43 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-04 6:43 [PATCH v1 net] ipv6: Fix null-ptr-deref in fib6_mtu() Kuniyuki Iwashima
2026-05-04 16:43 ` Ido Schimmel [this message]
2026-05-06 0:40 ` patchwork-bot+netdevbpf
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=20260504164325.GA393023@shredder \
--to=idosch@nvidia.com \
--cc=davem@davemloft.net \
--cc=dsahern@kernel.org \
--cc=edumazet@google.com \
--cc=horms@kernel.org \
--cc=kuba@kernel.org \
--cc=kuni1840@gmail.com \
--cc=kuniyu@google.com \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=syzbot+01f005f9c6387ca6f6dd@syzkaller.appspotmail.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