From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:58152 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752338AbcKRKhk (ORCPT ); Fri, 18 Nov 2016 05:37:40 -0500 Subject: Patch "tcp: fix return value for partial writes" has been added to the 4.8-stable tree To: edumazet@google.com, davem@davemloft.net, gregkh@linuxfoundation.org, ncardwell@google.com, soheil@google.com, willemb@google.com, ycheng@google.com Cc: , From: Date: Fri, 18 Nov 2016 11:37:17 +0100 Message-ID: <1479465437145158@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled tcp: fix return value for partial writes to the 4.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: tcp-fix-return-value-for-partial-writes.patch and it can be found in the queue-4.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From foo@baz Fri Nov 18 11:35:46 CET 2016 From: Eric Dumazet Date: Wed, 2 Nov 2016 14:41:50 -0700 Subject: tcp: fix return value for partial writes From: Eric Dumazet [ Upstream commit 79d8665b9545e128637c51cf7febde9c493b6481 ] 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 Cc: Willem de Bruijn Cc: Soheil Hassas Yeganeh Cc: Yuchung Cheng Cc: Neal Cardwell Tested-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1145,7 +1145,7 @@ 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); Patches currently in stable-queue which might be from edumazet@google.com are queue-4.8/net-__skb_flow_dissect-must-cap-its-return-value.patch queue-4.8/tcp-take-care-of-truncations-done-by-sk_filter.patch queue-4.8/net-clear-sk_err_soft-in-sk_clone_lock.patch queue-4.8/dccp-do-not-release-listeners-too-soon.patch queue-4.8/net-mangle-zero-checksum-in-skb_checksum_help.patch queue-4.8/tcp-fix-return-value-for-partial-writes.patch queue-4.8/ipv6-dccp-fix-out-of-bound-access-in-dccp_v6_err.patch queue-4.8/ipv6-dccp-add-missing-bind_conflict-to-dccp_ipv6_mapped.patch queue-4.8/tcp-fix-potential-memory-corruption.patch queue-4.8/dccp-do-not-send-reset-to-already-closed-sockets.patch queue-4.8/dccp-fix-out-of-bound-access-in-dccp_v4_err.patch queue-4.8/sock-fix-sendmmsg-for-partial-sendmsg.patch