diff options
| author | Eric Dumazet <edumazet@google.com> | 2022-02-01 07:52:54 +0100 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-02-02 05:21:40 +0100 |
| commit | 479f5547239d970d3833f15f54a6481fffdb91ec (patch) | |
| tree | 524d5d9fedeea8d2594e0b7bdb9f524da541143a /net/ipv4/tcp.c | |
| parent | af_packet: fix data-race in packet_setsockopt / packet_setsockopt (diff) | |
| download | linux-479f5547239d970d3833f15f54a6481fffdb91ec.tar.xz linux-479f5547239d970d3833f15f54a6481fffdb91ec.zip | |
tcp: fix mem under-charging with zerocopy sendmsg()
We got reports of following warning in inet_sock_destruct()
WARN_ON(sk_forward_alloc_get(sk));
Whenever we add a non zero-copy fragment to a pure zerocopy skb,
we have to anticipate that whole skb->truesize will be uncharged
when skb is finally freed.
skb->data_len is the payload length. But the memory truesize
estimated by __zerocopy_sg_from_iter() is page aligned.
Fixes: 9b65b17db723 ("net: avoid double accounting for pure zerocopy skbs")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Talal Ahmad <talalahmad@google.com>
Cc: Arjun Roy <arjunroy@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Link: https://lore.kernel.org/r/20220201065254.680532-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ipv4/tcp.c')
| -rw-r--r-- | net/ipv4/tcp.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 78e81465f5f3..bdf108f544a4 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1322,10 +1322,13 @@ new_segment: /* skb changing from pure zc to mixed, must charge zc */ if (unlikely(skb_zcopy_pure(skb))) { - if (!sk_wmem_schedule(sk, skb->data_len)) + u32 extra = skb->truesize - + SKB_TRUESIZE(skb_end_offset(skb)); + + if (!sk_wmem_schedule(sk, extra)) goto wait_for_space; - sk_mem_charge(sk, skb->data_len); + sk_mem_charge(sk, extra); skb_shinfo(skb)->flags &= ~SKBFL_PURE_ZEROCOPY; } |