netfilter: nft_flow_offload: reset dst in route object after setting up flow

[ Upstream commit 9e0f0430389be7696396c62f037be4bf72cf93e3 ]

dst is transferred to the flow object, route object does not own it
anymore.  Reset dst in route object, otherwise if flow_offload_add()
fails, error path releases dst twice, leading to a refcount underflow.

Fixes: a3c90f7a23 ("netfilter: nf_tables: flow offload expression")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Pablo Neira Ayuso 2024-02-21 12:32:58 +01:00 committed by Greg Kroah-Hartman
parent f2135bbf14
commit 558b00a30e
2 changed files with 14 additions and 4 deletions

View file

@ -275,7 +275,7 @@ nf_flow_table_offload_del_cb(struct nf_flowtable *flow_table,
}
void flow_offload_route_init(struct flow_offload *flow,
const struct nf_flow_route *route);
struct nf_flow_route *route);
int flow_offload_add(struct nf_flowtable *flow_table, struct flow_offload *flow);
void flow_offload_refresh(struct nf_flowtable *flow_table,

View file

@ -87,12 +87,22 @@ static u32 flow_offload_dst_cookie(struct flow_offload_tuple *flow_tuple)
return 0;
}
static struct dst_entry *nft_route_dst_fetch(struct nf_flow_route *route,
enum flow_offload_tuple_dir dir)
{
struct dst_entry *dst = route->tuple[dir].dst;
route->tuple[dir].dst = NULL;
return dst;
}
static int flow_offload_fill_route(struct flow_offload *flow,
const struct nf_flow_route *route,
struct nf_flow_route *route,
enum flow_offload_tuple_dir dir)
{
struct flow_offload_tuple *flow_tuple = &flow->tuplehash[dir].tuple;
struct dst_entry *dst = route->tuple[dir].dst;
struct dst_entry *dst = nft_route_dst_fetch(route, dir);
int i, j = 0;
switch (flow_tuple->l3proto) {
@ -146,7 +156,7 @@ static void nft_flow_dst_release(struct flow_offload *flow,
}
void flow_offload_route_init(struct flow_offload *flow,
const struct nf_flow_route *route)
struct nf_flow_route *route)
{
flow_offload_fill_route(flow, route, FLOW_OFFLOAD_DIR_ORIGINAL);
flow_offload_fill_route(flow, route, FLOW_OFFLOAD_DIR_REPLY);