Commit 920fc941 authored Mar 27, 2008 by Thomas Graf Committed by David S. Miller Mar 27, 2008

[ESP]: Ensure IV is in linear part of the skb to avoid BUG() due to OOB access

ESP does not account for the IV size when calling pskb_may_pull() to
ensure everything it accesses directly is within the linear part of a
potential fragment. This results in a BUG() being triggered when the
both the IPv4 and IPv6 ESP stack is fed with an skb where the first
fragment ends between the end of the esp header and the end of the IV.

This bug was found by Dirk Nehring <dnehring@gmx.net> .

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 732c8bd5

net/ipv4/esp4.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -336,7 +336,7 @@ static int esp_input(struct xfrm_state x, struct sk_buff skb)
		struct scatterlist *asg;
		int err = -EINVAL;

		if (!pskb_may_pull(skb, sizeof(*esph)))
		if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
		goto out;

		if (elen <= 0)

net/ipv6/esp6.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -282,7 +282,7 @@ static int esp6_input(struct xfrm_state x, struct sk_buff skb)
		struct scatterlist *sg;
		struct scatterlist *asg;

		if (!pskb_may_pull(skb, sizeof(*esph))) {
		if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead))) {
		ret = -EINVAL;
		goto out;
		}

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