From: Ben Hutchings <ben@decadent.org.uk>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Anarcheuz Fritz <anarcheuz@gmail.com>,
davem@davemloft.net, security@kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH net-stable] ipv4: keep skb->dst around in presence of IP options
Date: Tue, 21 Mar 2017 11:25:29 +0000 [thread overview]
Message-ID: <1490095529.4770.12.camel@decadent.org.uk> (raw)
In-Reply-To: <1490070228.16816.98.camel@edumazet-glaptop3.roam.corp.google.com>
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On Mon, 2017-03-20 at 21:23 -0700, Eric Dumazet wrote:
> From: Eric Dumazet <edumazet@google.com>
>
> Upstream commit 34b2cef20f19c87999fff3da4071e66937db9644
> ("ipv4: keep skb->dst around in presence of IP options") incorrectly
> root caused commit d826eb14ecef ("ipv4: PKTINFO doesnt need dst
> reference") as bug origin.
>
> This patch should fix the issue for 3.2.xx stable kernels, since IPv4
> options seem to get more traction these days, after years of oblivion
> ;)
>
> Fixes: f84af32cbca70 ("net: ip_queue_rcv_skb() helper"))
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Reported-by: Anarcheuz Fritz <anarcheuz@gmail.com>
> ---
>
> This is a backport for 3.2 kernels.
Added to the queue, thanks.
Ben.
> diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
> index b3648bbef0da..a6e1eeb02267 100644
> --- a/net/ipv4/ip_sockglue.c
> +++ b/net/ipv4/ip_sockglue.c
> @@ -1009,7 +1009,8 @@ e_inval:
> */
> int ip_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
> {
> - if (!(inet_sk(sk)->cmsg_flags & IP_CMSG_PKTINFO))
> + if (!(inet_sk(sk)->cmsg_flags & IP_CMSG_PKTINFO) &&
> + !IPCB(skb)->opt.optlen)
> skb_dst_drop(skb);
> return sock_queue_rcv_skb(sk, skb);
> }
>
>
--
Ben Hutchings
Power corrupts. Absolute power is kind of neat.
- John Lehman, Secretary of the US Navy
1981-1987
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next prev parent reply other threads:[~2017-03-21 11:25 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-20 4:59 PROBLEM: null-ptr deref in ip_options_echo may lead to denial of service Anarcheuz Fritz
2017-03-20 5:25 ` Eric Dumazet
2017-03-21 0:33 ` Ben Hutchings
2017-03-21 0:36 ` Ben Hutchings
2017-03-21 4:23 ` [PATCH net-stable] ipv4: keep skb->dst around in presence of IP options Eric Dumazet
2017-03-21 11:25 ` Ben Hutchings [this message]
2017-03-21 4:24 ` PROBLEM: null-ptr deref in ip_options_echo may lead to denial of service Eric Dumazet
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