diff options
| author | Antoine Tenart <atenart@kernel.org> | 2025-07-01 09:49:34 +0200 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-07-02 14:46:44 -0700 |
| commit | c2a2ff6b4db55647575260bf2227b0e09d46addb (patch) | |
| tree | 2ccc9eaa0fbe4f934ca8365e196fbc73dad30572 | |
| parent | 5186ff7e1d0e26aaef998ba18b31c79c28d1441f (diff) | |
net: ipv4: fix stat increase when udp early demux drops the packet
udp_v4_early_demux now returns drop reasons as it either returns 0 or
ip_mc_validate_source, which returns itself a drop reason. However its
use was not converted in ip_rcv_finish_core and the drop reason is
ignored, leading to potentially skipping increasing LINUX_MIB_IPRPFILTER
if the drop reason is SKB_DROP_REASON_IP_RPFILTER.
This is a fix and we're not converting udp_v4_early_demux to explicitly
return a drop reason to ease backports; this can be done as a follow-up.
Fixes: d46f827016d8 ("net: ip: make ip_mc_validate_source() return drop reason")
Cc: Menglong Dong <menglong8.dong@gmail.com>
Reported-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://patch.msgid.link/20250701074935.144134-1-atenart@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/ipv4/ip_input.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c index 30a5e9460d00..5a49eb99e5c4 100644 --- a/net/ipv4/ip_input.c +++ b/net/ipv4/ip_input.c @@ -319,8 +319,8 @@ static int ip_rcv_finish_core(struct net *net, const struct sk_buff *hint) { const struct iphdr *iph = ip_hdr(skb); - int err, drop_reason; struct rtable *rt; + int drop_reason; if (ip_can_use_hint(skb, iph, hint)) { drop_reason = ip_route_use_hint(skb, iph->daddr, iph->saddr, @@ -345,9 +345,10 @@ static int ip_rcv_finish_core(struct net *net, break; case IPPROTO_UDP: if (READ_ONCE(net->ipv4.sysctl_udp_early_demux)) { - err = udp_v4_early_demux(skb); - if (unlikely(err)) + drop_reason = udp_v4_early_demux(skb); + if (unlikely(drop_reason)) goto drop_error; + drop_reason = SKB_DROP_REASON_NOT_SPECIFIED; /* must reload iph, skb->head might have changed */ iph = ip_hdr(skb); |