From: Eric Dumazet <eric.dumazet@gmail.com>
To: Dave Jones <davej@redhat.com>
Cc: netdev@vger.kernel.org, Matthew Daley <mattjd@gmail.com>
Subject: Re: [v2] Fix NULL dereference in x25_recvmsg
Date: Wed, 02 Nov 2011 03:30:17 +0100 [thread overview]
Message-ID: <1320201017.4728.31.camel@edumazet-laptop> (raw)
In-Reply-To: <20111102022644.GB8512@redhat.com>
Le mardi 01 novembre 2011 à 22:26 -0400, Dave Jones a écrit :
> commit cb101ed2 in 3.0 introduced a bug in x25_recvmsg()
> When passed bogus junk from userspace, x25->neighbour can be NULL,
> as shown in this oops..
>
...
> Signed-off-by: Dave Jones <davej@redhat.com>
>
> diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c
> index 5f03e4e..3e16c6a 100644
> --- a/net/x25/af_x25.c
> +++ b/net/x25/af_x25.c
> @@ -1261,14 +1261,19 @@ static int x25_recvmsg(struct kiocb *iocb, struct socket *sock,
> struct x25_sock *x25 = x25_sk(sk);
> struct sockaddr_x25 *sx25 = (struct sockaddr_x25 *)msg->msg_name;
> size_t copied;
> - int qbit, header_len = x25->neighbour->extended ?
> - X25_EXT_MIN_LEN : X25_STD_MIN_LEN;
> -
> + int qbit, header_len;
> struct sk_buff *skb;
> unsigned char *asmptr;
> int rc = -ENOTCONN;
>
> lock_sock(sk);
> +
> + if (x25->neighbour == NULL)
> + goto out;
> +
> + header_len = x25->neighbour->extended ?
> + X25_EXT_MIN_LEN : X25_STD_MIN_LEN;
> +
> /*
> * This works for seqpacket too. The receiver has ordered the queue for
> * us! We do one quick check first though
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
next prev parent reply other threads:[~2011-11-02 2:30 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-02 1:53 Fix NULL dereference in x25_recvmsg Dave Jones
2011-11-02 2:10 ` Eric Dumazet
2011-11-02 2:15 ` Dave Jones
2011-11-02 2:19 ` Eric Dumazet
2011-11-02 2:21 ` Eric Dumazet
2011-11-02 2:16 ` Eric Dumazet
2011-11-02 2:26 ` [v2] " Dave Jones
2011-11-02 2:30 ` Eric Dumazet [this message]
2011-11-02 4:50 ` David Miller
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