From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Subject: [patch] netfilter: potential NULL dereference in get_inner_hdr() Date: Sat, 12 May 2012 14:00:03 +0300 Message-ID: <20120512110003.GB19472@elgon.mountain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Patrick McHardy , "David S. Miller" , netfilter-devel@vger.kernel.org, netfilter@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org, kernel-janitors@vger.kernel.org To: Pablo Neira Ayuso Return-path: Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-Id: netfilter-devel.vger.kernel.org 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 --- 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? */