ipv6: fix compiler warning in ipv6_exthdrs_len

Commit 299603e8370a93dd5d8e8d800f0dff1ce2c53d36 ("net-gro: Prepare GRO
stack for the upcoming tunneling support") used an uninitialized variable
which leads to the following compiler warning:

net/ipv6/ip6_offload.c: In function ‘ipv6_gro_complete’:
net/ipv6/ip6_offload.c:178:24: warning: ‘optlen’ may be used uninitialized in this function [-Wmaybe-uninitialized]
    opth = (void *)opth + optlen;
                        ^
net/ipv6/ip6_offload.c:164:22: note: ‘optlen’ was declared here
  int len = 0, proto, optlen;
                      ^
Fix it up.

Cc: Jerry Chu <hkchu@google.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c
index 7540a0ed75aee2a56606604429b3061183fa08f1..08861f1ff883844dacc0722011a06303aba190fa 100644 (file)
--- a/net/ipv6/ip6_offload.c
+++ b/net/ipv6/ip6_offload.c
@@ -161,7 +161,7 @@ static int ipv6_exthdrs_len(struct ipv6hdr *iph,
                            const struct net_offload **opps)
 {
        struct ipv6_opt_hdr *opth = NULL;
-       int len = 0, proto, optlen;
+       int len = 0, optlen = 0, proto;
 
        proto = iph->nexthdr;
        for (;;) {
@@ -172,11 +172,12 @@ static int ipv6_exthdrs_len(struct ipv6hdr *iph,
                        if (!((*opps)->flags & INET6_PROTO_GSO_EXTHDR))
                                break;
                }
-               if (opth == NULL)
+               if (opth == NULL) {
                        opth = (void *)(iph+1);
-               else
+               } else {
+                       optlen = ipv6_optlen(opth);
                        opth = (void *)opth + optlen;
-               optlen = ipv6_optlen(opth);
+               }
                len += optlen;
                proto = opth->nexthdr;
        }