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From: Dan Carpenter <dan.carpenter@oracle.com>
To: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Patrick McHardy <kaber@trash.net>,
	"David S. Miller" <davem@davemloft.net>,
	netfilter-devel@vger.kernel.org, netfilter@vger.kernel.org,
	coreteam@netfilter.org, netdev@vger.kernel.org,
	kernel-janitors@vger.kernel.org
Subject: [patch] netfilter: potential NULL dereference in get_inner_hdr()
Date: Sat, 12 May 2012 14:00:03 +0300	[thread overview]
Message-ID: <20120512110003.GB19472@elgon.mountain> (raw)

There is a typo in the error checking and "&&" was used instead of "||".
If skb_header_pointer() returns NULL then it leads to a NULL
dereference.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
Btw, this is new code and Sparse complains about endian bugs.

diff --git a/net/netfilter/xt_HMARK.c b/net/netfilter/xt_HMARK.c
index 32fbd73..5817d03 100644
--- a/net/netfilter/xt_HMARK.c
+++ b/net/netfilter/xt_HMARK.c
@@ -223,7 +223,7 @@ static int get_inner_hdr(const struct sk_buff *skb, int iphsz, int *nhoff)
 
 	/* Not enough header? */
 	icmph = skb_header_pointer(skb, *nhoff + iphsz, sizeof(_ih), &_ih);
-	if (icmph == NULL && icmph->type > NR_ICMP_TYPES)
+	if (icmph == NULL || icmph->type > NR_ICMP_TYPES)
 		return 0;
 
 	/* Error message? */

             reply	other threads:[~2012-05-12 11:00 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-05-12 11:00 Dan Carpenter [this message]
2012-05-14  7:36 ` [patch] netfilter: potential NULL dereference in get_inner_hdr() Hans Schillstrom
2012-05-14  7:38   ` David Miller
2012-05-14  7:53     ` Eric Dumazet
2012-05-14  8:00       ` Hans Schillstrom
2012-05-14  8:22         ` Pablo Neira Ayuso
2012-05-14  8:39   ` Dan Carpenter
2012-05-14  8:24 ` Pablo Neira Ayuso

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