From: Pablo Neira Ayuso pablo@netfilter.org

mainline inclusion from mainline-v6.8-rc6 commit 9e0f0430389be7696396c62f037be4bf72cf93e3 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9Q8LQ CVE: CVE-2024-27403

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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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: a3c90f7a2323 ("netfilter: nf_tables: flow offload expression") Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org

Conflicts: include/net/netfilter/nf_flow_table.h net/netfilter/nf_flow_table_core.c [This is because we did not backport fa502c865666, 8b9229d15877, 7a27f6ab4135] Signed-off-by: Liu Jian liujian56@huawei.com --- include/net/netfilter/nf_flow_table.h | 2 +- net/netfilter/nf_flow_table_core.c | 16 +++++++++++++--- 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/include/net/netfilter/nf_flow_table.h b/include/net/netfilter/nf_flow_table.h index b338638f2279..b49dfb415bad 100644 --- a/include/net/netfilter/nf_flow_table.h +++ b/include/net/netfilter/nf_flow_table.h @@ -207,7 +207,7 @@ nf_flow_table_offload_del_cb(struct nf_flowtable *flow_table, }

int 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, diff --git a/net/netfilter/nf_flow_table_core.c b/net/netfilter/nf_flow_table_core.c index d091d51b5e19..5a5faefb181d 100644 --- a/net/netfilter/nf_flow_table_core.c +++ b/net/netfilter/nf_flow_table_core.c @@ -74,13 +74,23 @@ struct flow_offload *flow_offload_alloc(struct nf_conn *ct) } EXPORT_SYMBOL_GPL(flow_offload_alloc);

+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 *other_dst = route->tuple[!dir].dst; - struct dst_entry *dst = route->tuple[dir].dst; + struct dst_entry *dst = nft_route_dst_fetch(route, dir);

if (!dst_hold_safe(route->tuple[dir].dst)) return -1; @@ -101,7 +111,7 @@ static int flow_offload_fill_route(struct flow_offload *flow, }

int flow_offload_route_init(struct flow_offload *flow, - const struct nf_flow_route *route) + struct nf_flow_route *route) { int err;