From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
To: roy.qing.li@gmail.com, netdev@vger.kernel.org
Cc: steffen.klassert@secunet.com
Subject: Re: [PATCH 2/2] xfrm6: fix a potential use after free in xfrm6_policy.c
Date: Mon, 20 Oct 2014 14:36:16 +0400 [thread overview]
Message-ID: <5444E5A0.9040004@cogentembedded.com> (raw)
In-Reply-To: <1413794954-16967-2-git-send-email-roy.qing.li@gmail.com>
Hello.
On 10/20/2014 12:49 PM, roy.qing.li@gmail.com wrote:
> From: Li RongQing <roy.qing.li@gmail.com>
> pskb_may_pull() maybe change skb->data and make nh and exthdr pointer
> oboslete, so recompute the nd and exthdr
> Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
> ---
> net/ipv6/xfrm6_policy.c | 11 ++++++++---
> 1 file changed, 8 insertions(+), 3 deletions(-)
> diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
> index ac49f84..115fd3b 100644
> --- a/net/ipv6/xfrm6_policy.c
> +++ b/net/ipv6/xfrm6_policy.c
> @@ -170,8 +170,10 @@ _decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse)
> case IPPROTO_DCCP:
> if (!onlyproto && (nh + offset + 4 < skb->data ||
> pskb_may_pull(skb, nh + offset + 4 - skb->data))) {
> - __be16 *ports = (__be16 *)exthdr;
> + __be16 *ports;
>
> + nh = skb_network_header(skb);
> + ports = (__be16*)(nh + offset);
Please insert a space between '__be16' and * like it was done in the
deleted assignment.
[...]
> @@ -180,8 +182,10 @@ _decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse)
>
> case IPPROTO_ICMPV6:
> if (!onlyproto && pskb_may_pull(skb, nh + offset + 2 - skb->data)) {
> - u8 *icmp = (u8 *)exthdr;
> + u8 *icmp;
>
> + nh = skb_network_header(skb);
> + icmp = (u8*)(nh + offset);
Likewise.
[...]
> @@ -192,8 +196,9 @@ _decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse)
> case IPPROTO_MH:
> if (!onlyproto && pskb_may_pull(skb, nh + offset + 3 - skb->data)) {
> struct ip6_mh *mh;
> - mh = (struct ip6_mh *)exthdr;
>
> + nh = skb_network_header(skb);
> + mh = (struct ip6_mh*)(nh + offset);
Likewise.
[...]
WBR, Sergei
next prev parent reply other threads:[~2014-10-20 10:36 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-20 8:49 [PATCH 1/2] xfrm: fix a potential use after free in xfrm4_policy.c roy.qing.li
2014-10-20 8:49 ` [PATCH 2/2] xfrm6: fix a potential use after free in xfrm6_policy.c roy.qing.li
2014-10-20 10:36 ` Sergei Shtylyov [this message]
2014-10-22 1:42 ` [PATCH 1/2] xfrm: fix a potential use after free in xfrm4_policy.c David Miller
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