[PATCH 5.11 071/122] netfilter: flowtable: fix NAT IPv6 offload mangling

Greg Kroah-Hartman
2021-04-19T13:15:21Z

From: Pablo Neira Ayuso <pablo@netfilter.org>

commit 0e07e25b481aa021e4b48085ecb8a049e9614510 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/netfilter/nf_flow_table_offload.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- 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(str
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);
}
}