From: Zhouyi Zhou <yizhouzhou@xxxxxxxxx>
I think hackers chould build a malicious h323 packet to overflow
the pointer p which will panic during the memcpy(addr, p, len)
For example, he may fabricate a very large taddr->ipAddress.ip;
Signed-off-by: Zhouyi Zhou <zhouzhouyi@xxxxxxxxx>
---
net/netfilter/nf_conntrack_h323_main.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/net/netfilter/nf_conntrack_h323_main.c b/net/netfilter/nf_conntrack_h323_main.c
index 9511af0..3b3dd8c 100644
--- a/net/netfilter/nf_conntrack_h323_main.c
+++ b/net/netfilter/nf_conntrack_h323_main.c
@@ -110,6 +110,10 @@ int (*nat_q931_hook) (struct sk_buff *skb,
static DEFINE_SPINLOCK(nf_h323_lock);
static char *h323_buffer;
+#define CHECK_BOUND(p, n) do { \
+ if (((p - h323_buffer) + n) > 65536) \
+ return 0; \
+} while (0)
static struct nf_conntrack_helper nf_conntrack_helper_h245;
static struct nf_conntrack_helper nf_conntrack_helper_q931[];
@@ -247,6 +251,8 @@ static int get_h245_addr(struct nf_conn *ct, const unsigned char *data,
return 0;
}
+ CHECK_BOUND(p, len);
+
memcpy(addr, p, len);
memset((void *)addr + len, 0, sizeof(*addr) - len);
memcpy(port, p + len, sizeof(__be16));
@@ -669,6 +675,8 @@ int get_h225_addr(struct nf_conn *ct, unsigned char *data,
return 0;
}
+ CHECK_BOUND(p, len);
+
memcpy(addr, p, len);
memset((void *)addr + len, 0, sizeof(*addr) - len);
memcpy(port, p + len, sizeof(__be16));
--
1.7.10.4
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