diff options
| author | Stanislav Fomichev <sdf@fomichev.me> | 2025-08-18 08:40:28 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-08-19 17:54:19 -0700 |
| commit | 15488d4d8dc10a575f32cc692b6c9aa99f66bc7b (patch) | |
| tree | 8dd3d555fd6e3b3a233f221430846b67c873af76 | |
| parent | c829aab21ed55d9e38346604259aa3ff88d17274 (diff) | |
netfilter: Switch to skb_dstref_steal to clear dst_entry
Going forward skb_dst_set will assert that skb dst_entry
is empty during skb_dst_set. skb_dstref_steal is added to reset
existing entry without doing refcnt. Switch to skb_dstref_steal
in ip[6]_route_me_harder and add a comment on why it's safe
to skip skb_dstref_restore.
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250818154032.3173645-4-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/ipv4/netfilter.c | 5 | ||||
| -rw-r--r-- | net/ipv6/netfilter.c | 5 |
2 files changed, 8 insertions, 2 deletions
diff --git a/net/ipv4/netfilter.c b/net/ipv4/netfilter.c index 0565f001120d..e60e54e7945d 100644 --- a/net/ipv4/netfilter.c +++ b/net/ipv4/netfilter.c @@ -65,7 +65,10 @@ int ip_route_me_harder(struct net *net, struct sock *sk, struct sk_buff *skb, un if (!(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) && xfrm_decode_session(net, skb, flowi4_to_flowi(&fl4), AF_INET) == 0) { struct dst_entry *dst = skb_dst(skb); - skb_dst_set(skb, NULL); + /* ignore return value from skb_dstref_steal, xfrm_lookup takes + * care of dropping the refcnt if needed. + */ + skb_dstref_steal(skb); dst = xfrm_lookup(net, dst, flowi4_to_flowi(&fl4), sk, 0); if (IS_ERR(dst)) return PTR_ERR(dst); diff --git a/net/ipv6/netfilter.c b/net/ipv6/netfilter.c index 45f9105f9ac1..46540a5a4331 100644 --- a/net/ipv6/netfilter.c +++ b/net/ipv6/netfilter.c @@ -63,7 +63,10 @@ int ip6_route_me_harder(struct net *net, struct sock *sk_partial, struct sk_buff #ifdef CONFIG_XFRM if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) && xfrm_decode_session(net, skb, flowi6_to_flowi(&fl6), AF_INET6) == 0) { - skb_dst_set(skb, NULL); + /* ignore return value from skb_dstref_steal, xfrm_lookup takes + * care of dropping the refcnt if needed. + */ + skb_dstref_steal(skb); dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0); if (IS_ERR(dst)) return PTR_ERR(dst); |