af_unix: Set drop reason in unix_stream_read_skb().

unix_stream_read_skb() is called when BPF SOCKMAP reads some data
from a socket in the map.

SOCKMAP does not support MSG_OOB, and reading OOB results in a drop.

Let's set drop reasons respectively.

  * SOCKET_CLOSE  : the socket in SOCKMAP was close()d
  * UNIX_SKIP_OOB : OOB was read from the socket in SOCKMAP

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250116053441.5758-7-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index e31fda1d319f6542e40304171e0c0760d7f76fb9..de4966e1b7ff95a4eecb8c2ba29a318c65d6459a 100644 (file)
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -2724,7 +2724,7 @@ static int unix_stream_read_skb(struct sock *sk, skb_read_actor_t recv_actor)
 
                if (sock_flag(sk, SOCK_DEAD)) {
                        unix_state_unlock(sk);
-                       kfree_skb(skb);
+                       kfree_skb_reason(skb, SKB_DROP_REASON_SOCKET_CLOSE);
                        return -ECONNRESET;
                }
 
@@ -2738,7 +2738,7 @@ static int unix_stream_read_skb(struct sock *sk, skb_read_actor_t recv_actor)
                unix_state_unlock(sk);
 
                if (drop) {
-                       kfree_skb(skb);
+                       kfree_skb_reason(skb, SKB_DROP_REASON_UNIX_SKIP_OOB);
                        return -EAGAIN;
                }
        }