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 <[email protected]>
Cc: Soheil Hassas Yeganeh <[email protected]>
Cc: Willem de Bruijn <[email protected]>
Acked-by: Soheil Hassas Yeganeh <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

0 files changed, 0 insertions, 0 deletions