From: Eric Dumazet <eduma...@google.com>

Paul Moore tracked a regression caused by a recent commit, which
mistakenly assumed that sk_filter() could be avoided if socket
had no current BPF filter.

The intent was to avoid udp_lib_checksum_complete() overhead.

But sk_filter() also checks skb_pfmemalloc() and
security_sock_rcv_skb(), so better call it.

Fixes: e6afc8ace6dd ("udp: remove headers from UDP packets before queueing")
Signed-off-by: Eric Dumazet <eduma...@google.com>
Reported-by: Paul Moore <p...@paul-moore.com>
Tested-by: Paul Moore <p...@paul-moore.com>
Tested-by: Stephen Smalley <s...@tycho.nsa.gov>
Cc: samanthakumar <samanthaku...@google.com>
---
 net/ipv4/udp.c |   10 +++++-----
 net/ipv6/udp.c |   12 ++++++------
 2 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index d56c0559b477..0ff31d97d485 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1618,12 +1618,12 @@ int udp_queue_rcv_skb(struct sock *sk, struct sk_buff 
*skb)
                }
        }
 
-       if (rcu_access_pointer(sk->sk_filter)) {
-               if (udp_lib_checksum_complete(skb))
+       if (rcu_access_pointer(sk->sk_filter) &&
+           udp_lib_checksum_complete(skb))
                        goto csum_error;
-               if (sk_filter(sk, skb))
-                       goto drop;
-       }
+
+       if (sk_filter(sk, skb))
+               goto drop;
 
        udp_csum_pull_header(skb);
        if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 2da1896af934..f421c9f23c5b 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -653,12 +653,12 @@ int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff 
*skb)
                }
        }
 
-       if (rcu_access_pointer(sk->sk_filter)) {
-               if (udp_lib_checksum_complete(skb))
-                       goto csum_error;
-               if (sk_filter(sk, skb))
-                       goto drop;
-       }
+       if (rcu_access_pointer(sk->sk_filter) &&
+           udp_lib_checksum_complete(skb))
+               goto csum_error;
+
+       if (sk_filter(sk, skb))
+               goto drop;
 
        udp_csum_pull_header(skb);
        if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {


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