diff options
| author | Eric Dumazet <edumazet@google.com> | 2019-04-19 16:02:03 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-04-19 16:42:33 -0700 |
| commit | d7cc399e1227e74e44f78847d9732a228b46cc91 (patch) | |
| tree | d83b970c017bc2c96286be18e81e20dd43eaaf86 /net | |
| parent | 0a9798c123d0eee43e55cc9361b0c10314bb2250 (diff) | |
| download | lwn-d7cc399e1227e74e44f78847d9732a228b46cc91.tar.gz lwn-d7cc399e1227e74e44f78847d9732a228b46cc91.zip | |
tcp: properly reset skb->truesize for tx recycling
tcp sendmsg() and sendpage() normally advance skb->data_len
and skb->truesize by the payload added to an skb.
But sendmsg(fd, ..., MSG_ZEROCOPY) has to account for whole pages,
even if a single byte of payload is used in the page.
This means that we can not assume skb->truesize can be adjusted
by skb->data_len. We must instead overwrite its value.
Otherwise skb->truesize is too big and can hit socket sndbuf limit,
especially if the skb is recycled multiple times :/
Fixes: 472c2e07eef0 ("tcp: add one skb cache for tx")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 603e770d59b3..f7567a3698eb 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -868,7 +868,7 @@ struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp, if (likely(!size)) { skb = sk->sk_tx_skb_cache; if (skb && !skb_cloned(skb)) { - skb->truesize -= skb->data_len; + skb->truesize = SKB_TRUESIZE(skb_end_offset(skb)); sk->sk_tx_skb_cache = NULL; pskb_trim(skb, 0); INIT_LIST_HEAD(&skb->tcp_tsorted_anchor); |