From mboxrd@z Thu Jan 1 00:00:00 1970 From: kaber@trash.net Subject: [PATCH 2/8] netfilter: ip_queue: Fix small leak in ipq_build_packet_message() Date: Tue, 30 Aug 2011 16:41:15 +0200 Message-ID: <1314715281-26233-3-git-send-email-kaber@trash.net> References: <1314715281-26233-1-git-send-email-kaber@trash.net> Cc: netfilter-devel@vger.kernel.org, netdev@vger.kernel.org To: davem@davemloft.net Return-path: In-Reply-To: <1314715281-26233-1-git-send-email-kaber@trash.net> Sender: netdev-owner@vger.kernel.org List-Id: netfilter-devel.vger.kernel.org From: Jesper Juhl ipq_build_packet_message() in net/ipv4/netfilter/ip_queue.c and net/ipv6/netfilter/ip6_queue.c contain a small potential mem leak as far as I can tell. We allocate memory for 'skb' with alloc_skb() annd then call nlh = NLMSG_PUT(skb, 0, 0, IPQM_PACKET, size - sizeof(*nlh)); NLMSG_PUT is a macro NLMSG_PUT(skb, pid, seq, type, len) \ NLMSG_NEW(skb, pid, seq, type, len, 0) that expands to NLMSG_NEW, which is also a macro which expands to: NLMSG_NEW(skb, pid, seq, type, len, flags) \ ({ if (unlikely(skb_tailroom(skb) < (int)NLMSG_SPACE(len))) \ goto nlmsg_failure; \ __nlmsg_put(skb, pid, seq, type, len, flags); }) If we take the true branch of the 'if' statement and 'goto nlmsg_failure', then we'll, at that point, return from ipq_build_packet_message() without having assigned 'skb' to anything and we'll leak the memory we allocated for it when it goes out of scope. Fix this by placing a 'kfree(skb)' at 'nlmsg_failure'. I admit that I do not know how likely this to actually happen or even if there's something that guarantees that it will never happen - I'm not that familiar with this code, but if that is so, I've not been able to spot it. Signed-off-by: Jesper Juhl Signed-off-by: Patrick McHardy --- net/ipv4/netfilter/ip_queue.c | 1 + net/ipv6/netfilter/ip6_queue.c | 1 + 2 files changed, 2 insertions(+), 0 deletions(-) diff --git a/net/ipv4/netfilter/ip_queue.c b/net/ipv4/netfilter/ip_queue.c index 5c9b9d9..48f7d5b 100644 --- a/net/ipv4/netfilter/ip_queue.c +++ b/net/ipv4/netfilter/ip_queue.c @@ -218,6 +218,7 @@ ipq_build_packet_message(struct nf_queue_entry *entry, int *errp) return skb; nlmsg_failure: + kfree_skb(skb); *errp = -EINVAL; printk(KERN_ERR "ip_queue: error creating packet message\n"); return NULL; diff --git a/net/ipv6/netfilter/ip6_queue.c b/net/ipv6/netfilter/ip6_queue.c index 2493948..87b243a 100644 --- a/net/ipv6/netfilter/ip6_queue.c +++ b/net/ipv6/netfilter/ip6_queue.c @@ -218,6 +218,7 @@ ipq_build_packet_message(struct nf_queue_entry *entry, int *errp) return skb; nlmsg_failure: + kfree_skb(skb); *errp = -EINVAL; printk(KERN_ERR "ip6_queue: error creating packet message\n"); return NULL; -- 1.7.2.3