IPVS not check the length of pp->name, use sprintf will cause stack buffer overflow.
struct ip_vs_protocol{} declare name as char *, if register a protocol as:
struct ip_vs_protocol ip_vs_test = {
.name = "aaaaaaaa....128...aaa",
.debug_packet = ip_vs_tcpudp_debug_packet,
};
when called ip_vs_tcpudp_debug_packet(), sprintf(buf, "%s TRUNCATED", pp->name);
will cause stack buffer overflow.
Signed-off-by: Zhitong Wang <zhitong.wangzt@xxxxxxxxxxxxxxx>
---
net/netfilter/ipvs/ip_vs_proto.c | 16 ++++++++--------
net/netfilter/ipvs/ip_vs_proto_ah_esp.c | 8 ++++----
2 files changed, 12 insertions(+), 12 deletions(-)
diff --git a/net/netfilter/ipvs/ip_vs_proto.c b/net/netfilter/ipvs/ip_vs_proto.c
index 0e58455..8143318 100644
--- a/net/netfilter/ipvs/ip_vs_proto.c
+++ b/net/netfilter/ipvs/ip_vs_proto.c
@@ -166,9 +166,9 @@ 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);
+ snprintf(buf, sizeof(buf), "%s TRUNCATED", pp->name);
else if (ih->frag_off & htons(IP_OFFSET))
- sprintf(buf, "%s %pI4->%pI4 frag",
+ snprintf(buf, sizeof(buf), "%s %pI4->%pI4 frag",
pp->name, &ih->saddr, &ih->daddr);
else {
__be16 _ports[2], *pptr
@@ -176,10 +176,10 @@ ip_vs_tcpudp_debug_packet_v4(struct ip_vs_protocol *pp,
pptr = skb_header_pointer(skb, offset + ih->ihl*4,
sizeof(_ports), _ports);
if (pptr == NULL)
- sprintf(buf, "%s TRUNCATED %pI4->%pI4",
+ snprintf(buf, sizeof(buf), "%s TRUNCATED %pI4->%pI4",
pp->name, &ih->saddr, &ih->daddr);
else
- sprintf(buf, "%s %pI4:%u->%pI4:%u",
+ snprintf(buf, sizeof(buf), "%s %pI4:%u->%pI4:%u",
pp->name,
&ih->saddr, ntohs(pptr[0]),
&ih->daddr, ntohs(pptr[1]));
@@ -200,9 +200,9 @@ 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);
+ snprintf(buf, sizeof(buf), "%s TRUNCATED", pp->name);
else if (ih->nexthdr == IPPROTO_FRAGMENT)
- sprintf(buf, "%s %pI6->%pI6 frag",
+ snprintf(buf, sizeof(buf), "%s %pI6->%pI6 frag",
pp->name, &ih->saddr, &ih->daddr);
else {
__be16 _ports[2], *pptr;
@@ -210,10 +210,10 @@ ip_vs_tcpudp_debug_packet_v6(struct ip_vs_protocol *pp,
pptr = skb_header_pointer(skb, offset + sizeof(struct ipv6hdr),
sizeof(_ports), _ports);
if (pptr == NULL)
- sprintf(buf, "%s TRUNCATED %pI6->%pI6",
+ snprintf(buf, sizeof(buf), "%s TRUNCATED %pI6->%pI6",
pp->name, &ih->saddr, &ih->daddr);
else
- sprintf(buf, "%s %pI6:%u->%pI6:%u",
+ snprintf(buf, sizeof(buf), "%s %pI6:%u->%pI6:%u",
pp->name,
&ih->saddr, ntohs(pptr[0]),
&ih->daddr, ntohs(pptr[1]));
diff --git a/net/netfilter/ipvs/ip_vs_proto_ah_esp.c b/net/netfilter/ipvs/ip_vs_proto_ah_esp.c
index c30b43c..ce795ab 100644
--- a/net/netfilter/ipvs/ip_vs_proto_ah_esp.c
+++ b/net/netfilter/ipvs/ip_vs_proto_ah_esp.c
@@ -136,9 +136,9 @@ 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);
+ snprintf(buf, sizeof(buf), "%s TRUNCATED", pp->name);
else
- sprintf(buf, "%s %pI4->%pI4",
+ snprintf(buf, sizeof(buf), "%s %pI4->%pI4",
pp->name, &ih->saddr, &ih->daddr);
pr_debug("%s: %s\n", msg, buf);
@@ -154,9 +154,9 @@ 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);
+ snprintf(buf, sizeof(buf), "%s TRUNCATED", pp->name);
else
- sprintf(buf, "%s %pI6->%pI6",
+ snprintf(buf, sizeof(buf), "%s %pI6->%pI6",
pp->name, &ih->saddr, &ih->daddr);
pr_debug("%s: %s\n", msg, buf);
--
1.6.5.3
--
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