From 3d91c1a848c812e0e66e7e57f076667822cb460e Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Thu, 8 Apr 2010 13:35:47 +0200 Subject: [PATCH] IPVS: fix potential stack overflow with overly long protocol names 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 0e584553819d..27add971bb13 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 c30b43c36cd7..1892dfc12fdd 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 -- 2.20.1