[dpdk-dev] [PATCH] examples/ipsec-secgw: fix ip version check

[Tomasz Duszynski <tdu@semihalf.com>]

Since new_ip and ip4 are overlapping buffers copying ip4 over new_ip
using memmove() might overwrite memory at ip4. This could happen if
following condition holds:

ip_hdr_len > sizeof(struct esp_hdr) + sa->iv_len

Thus using ip4 to check ip version is wrong as it might not contain
proper value.

Fixes: f159e70b0922 ("examples/ipsec-secgw: support transport mode")
Cc: stable@dpdk.org

Signed-off-by: Tomasz Duszynski <tdu@semihalf.com>
---
 examples/ipsec-secgw/esp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/ipsec-secgw/esp.c b/examples/ipsec-secgw/esp.c
index 2897840..063e63f 100644
--- a/examples/ipsec-secgw/esp.c
+++ b/examples/ipsec-secgw/esp.c
@@ -307,8 +307,8 @@ esp_outbound(struct rte_mbuf *m, struct ipsec_sa *sa,
 				sizeof(struct esp_hdr) + sa->iv_len);
 		memmove(new_ip, ip4, ip_hdr_len);
 		esp = (struct esp_hdr *)(new_ip + ip_hdr_len);
+		ip4 = (struct ip *)new_ip;
 		if (likely(ip4->ip_v == IPVERSION)) {
-			ip4 = (struct ip *)new_ip;
 			ip4->ip_p = IPPROTO_ESP;
 			ip4->ip_len = htons(rte_pktmbuf_data_len(m));
 		} else {
-- 
2.7.4