tcp: fix tcp fin memory accounting

tcp_send_fin() does not account for the memory it allocates properly, so sk_forward_alloc can be negative in cases where we've sent a FIN: ss example output (ss -amn | grep -B1 f4294): tcp FIN-WAIT-1 0 1 192.168.0.1:45520 192.0.2.1:8080 skmem:(r0,rb87380,t0,tb87380,f4294966016,w1280,o0,bl0) Acked-by: Eric Dumazet <[email protected]> Signed-off-by: David S. Miller <[email protected]>
torvalds · Mar 20, 2015 · d22e153 · d22e153
1 parent 73ba57b
commit d22e153
Showing 1 changed file with 1 addition and 5 deletions.
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
@@ -2773,15 +2773,11 @@ void tcp_send_fin(struct sock *sk)
 	} else {
 		/* Socket is locked, keep trying until memory is available. */
 		for (;;) {
-			skb = alloc_skb_fclone(MAX_TCP_HEADER,
-					       sk->sk_allocation);
+			skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation);
 			if (skb)
 				break;
 			yield();
 		}
-
-		/* Reserve space for headers and prepare control bits. */
-		skb_reserve(skb, MAX_TCP_HEADER);
 		/* FIN eats a sequence byte, write_seq advanced by tcp_queue_skb(). */
 		tcp_init_nondata_skb(skb, tp->write_seq,
 				     TCPHDR_ACK | TCPHDR_FIN);