path: root/net
diff options
authorEric Dumazet <edumazet@google.com>2016-11-02 14:41:50 -0700
committerDavid S. Miller <davem@davemloft.net>2016-11-03 16:12:06 -0400
commit79d8665b9545e128637c51cf7febde9c493b6481 (patch)
tree5a25d00198c300afd94f10b59ee5e8c87ee9d0d0 /net
parentipv4: allow local fragmentation in ip_finish_output_gso() (diff)
tcp: fix return value for partial writes
After my commit, tcp_sendmsg() might restart its loop after processing socket backlog. If sk_err is set, we blindly return an error, even though we copied data to user space before. We should instead return number of bytes that could be copied, otherwise user space might resend data and corrupt the stream. This might happen if another thread is using recvmsg(MSG_ERRQUEUE) to process timestamps. Issue was diagnosed by Soheil and Willem, big kudos to them ! Fixes: d41a69f1d390f ("tcp: make tcp_sendmsg() aware of socket backlog") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Willem de Bruijn <willemb@google.com> Cc: Soheil Hassas Yeganeh <soheil@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Neal Cardwell <ncardwell@google.com> Tested-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 18238ef8135a..814af89c1bd3 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1164,7 +1164,7 @@ restart:
err = -EPIPE;
if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
- goto out_err;
+ goto do_error;
sg = !!(sk->sk_route_caps & NETIF_F_SG);