From mboxrd@z Thu Jan 1 00:00:00 1970 From: kaber@trash.net Subject: [PATCH 55/84] IPVS: fix potential stack overflow with overly long protocol names Date: Mon, 10 May 2010 22:18:26 +0200 Message-ID: <1273522735-24672-56-git-send-email-kaber@trash.net> References: <1273522735-24672-1-git-send-email-kaber@trash.net> Cc: netfilter-devel@vger.kernel.org, netdev@vger.kernel.org To: davem@davemloft.net Return-path: Received: from stinky.trash.net ([213.144.137.162]:54523 "EHLO stinky.trash.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756708Ab0EJUTT (ORCPT ); Mon, 10 May 2010 16:19:19 -0400 In-Reply-To: <1273522735-24672-1-git-send-email-kaber@trash.net> Sender: netfilter-devel-owner@vger.kernel.org List-ID: From: Patrick McHardy When protocols use very long names, the sprintf calls might overflow the on-stack buffer. No protocol in the kernel does this however. Print the protocol name in the pr_debug statement directly to avoid this. Based on patch by Zhitong Wang Acked-by: Simon Horman Signed-off-by: Patrick McHardy --- net/netfilter/ipvs/ip_vs_proto.c | 28 ++++++++++++---------------- net/netfilter/ipvs/ip_vs_proto_ah_esp.c | 14 ++++++-------- 2 files changed, 18 insertions(+), 24 deletions(-) diff --git a/net/netfilter/ipvs/ip_vs_proto.c b/net/netfilter/ipvs/ip_vs_proto.c index 0e58455..27add97 100644 --- a/net/netfilter/ipvs/ip_vs_proto.c +++ b/net/netfilter/ipvs/ip_vs_proto.c @@ -166,26 +166,24 @@ ip_vs_tcpudp_debug_packet_v4(struct ip_vs_protocol *pp, ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph); if (ih == NULL) - sprintf(buf, "%s TRUNCATED", pp->name); + sprintf(buf, "TRUNCATED"); else if (ih->frag_off & htons(IP_OFFSET)) - sprintf(buf, "%s %pI4->%pI4 frag", - pp->name, &ih->saddr, &ih->daddr); + sprintf(buf, "%pI4->%pI4 frag", &ih->saddr, &ih->daddr); else { __be16 _ports[2], *pptr ; pptr = skb_header_pointer(skb, offset + ih->ihl*4, sizeof(_ports), _ports); if (pptr == NULL) - sprintf(buf, "%s TRUNCATED %pI4->%pI4", - pp->name, &ih->saddr, &ih->daddr); + sprintf(buf, "TRUNCATED %pI4->%pI4", + &ih->saddr, &ih->daddr); else - sprintf(buf, "%s %pI4:%u->%pI4:%u", - pp->name, + sprintf(buf, "%pI4:%u->%pI4:%u", &ih->saddr, ntohs(pptr[0]), &ih->daddr, ntohs(pptr[1])); } - pr_debug("%s: %s\n", msg, buf); + pr_debug("%s: %s %s\n", msg, pp->name, buf); } #ifdef CONFIG_IP_VS_IPV6 @@ -200,26 +198,24 @@ ip_vs_tcpudp_debug_packet_v6(struct ip_vs_protocol *pp, ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph); if (ih == NULL) - sprintf(buf, "%s TRUNCATED", pp->name); + sprintf(buf, "TRUNCATED"); else if (ih->nexthdr == IPPROTO_FRAGMENT) - sprintf(buf, "%s %pI6->%pI6 frag", - pp->name, &ih->saddr, &ih->daddr); + sprintf(buf, "%pI6->%pI6 frag", &ih->saddr, &ih->daddr); else { __be16 _ports[2], *pptr; pptr = skb_header_pointer(skb, offset + sizeof(struct ipv6hdr), sizeof(_ports), _ports); if (pptr == NULL) - sprintf(buf, "%s TRUNCATED %pI6->%pI6", - pp->name, &ih->saddr, &ih->daddr); + sprintf(buf, "TRUNCATED %pI6->%pI6", + &ih->saddr, &ih->daddr); else - sprintf(buf, "%s %pI6:%u->%pI6:%u", - pp->name, + sprintf(buf, "%pI6:%u->%pI6:%u", &ih->saddr, ntohs(pptr[0]), &ih->daddr, ntohs(pptr[1])); } - pr_debug("%s: %s\n", msg, buf); + pr_debug("%s: %s %s\n", msg, pp->name, buf); } #endif diff --git a/net/netfilter/ipvs/ip_vs_proto_ah_esp.c b/net/netfilter/ipvs/ip_vs_proto_ah_esp.c index c30b43c..1892dfc 100644 --- a/net/netfilter/ipvs/ip_vs_proto_ah_esp.c +++ b/net/netfilter/ipvs/ip_vs_proto_ah_esp.c @@ -136,12 +136,11 @@ ah_esp_debug_packet_v4(struct ip_vs_protocol *pp, const struct sk_buff *skb, ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph); if (ih == NULL) - sprintf(buf, "%s TRUNCATED", pp->name); + sprintf(buf, "TRUNCATED"); else - sprintf(buf, "%s %pI4->%pI4", - pp->name, &ih->saddr, &ih->daddr); + sprintf(buf, "%pI4->%pI4", &ih->saddr, &ih->daddr); - pr_debug("%s: %s\n", msg, buf); + pr_debug("%s: %s %s\n", msg, pp->name, buf); } #ifdef CONFIG_IP_VS_IPV6 @@ -154,12 +153,11 @@ ah_esp_debug_packet_v6(struct ip_vs_protocol *pp, const struct sk_buff *skb, ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph); if (ih == NULL) - sprintf(buf, "%s TRUNCATED", pp->name); + sprintf(buf, "TRUNCATED"); else - sprintf(buf, "%s %pI6->%pI6", - pp->name, &ih->saddr, &ih->daddr); + sprintf(buf, "%pI6->%pI6", &ih->saddr, &ih->daddr); - pr_debug("%s: %s\n", msg, buf); + pr_debug("%s: %s %s\n", msg, pp->name, buf); } #endif -- 1.7.0.4