netfilter: flowtable: fix NAT IPv6 offload mangling

Fix out-of-bound access in the address array.

Fixes: 5c27d8d76ce8 ("netfilter: nf_flow_table_offload: add IPv6 support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nf_flow_table_offload.c b/net/netfilter/nf_flow_table_offload.c
index 2a6993fa40d78dcccce1e4425ab3cabf6120a899..1c5460e7bce875d2c9cff8bdb6a2c8c5b9ee4f44 100644 (file)
--- a/net/netfilter/nf_flow_table_offload.c
+++ b/net/netfilter/nf_flow_table_offload.c
@@ -305,12 +305,12 @@ static void flow_offload_ipv6_mangle(struct nf_flow_rule *flow_rule,
                                     const __be32 *addr, const __be32 *mask)
 {
        struct flow_action_entry *entry;
-       int i;
+       int i, j;
 
-       for (i = 0; i < sizeof(struct in6_addr) / sizeof(u32); i += sizeof(u32)) {
+       for (i = 0, j = 0; i < sizeof(struct in6_addr) / sizeof(u32); i += sizeof(u32), j++) {
                entry = flow_action_entry_next(flow_rule);
                flow_offload_mangle(entry, FLOW_ACT_MANGLE_HDR_TYPE_IP6,
-                                   offset + i, &addr[i], mask);
+                                   offset + i, &addr[j], mask);
        }
 }