Commit b182ecc8 authored by Josh Hunt's avatar Josh Hunt Committed by Sasha Levin

tcp: fix tcp fin memory accounting

[ Upstream commit d22e1537 ]

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: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
parent 7f249ac5
...@@ -2739,15 +2739,11 @@ void tcp_send_fin(struct sock *sk) ...@@ -2739,15 +2739,11 @@ void tcp_send_fin(struct sock *sk)
} else { } else {
/* Socket is locked, keep trying until memory is available. */ /* Socket is locked, keep trying until memory is available. */
for (;;) { for (;;) {
skb = alloc_skb_fclone(MAX_TCP_HEADER, skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation);
sk->sk_allocation);
if (skb) if (skb)
break; break;
yield(); 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(). */ /* FIN eats a sequence byte, write_seq advanced by tcp_queue_skb(). */
tcp_init_nondata_skb(skb, tp->write_seq, tcp_init_nondata_skb(skb, tp->write_seq,
TCPHDR_ACK | TCPHDR_FIN); TCPHDR_ACK | TCPHDR_FIN);
......
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