This is a note to let you know that I've just added the patch titled sock: fix sendmmsg for partial sendmsg 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: sock-fix-sendmmsg-for-partial-sendmsg.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 <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Fri Nov 18 11:35:46 CET 2016 From: Soheil Hassas Yeganeh <soheil@xxxxxxxxxx> Date: Fri, 4 Nov 2016 15:36:49 -0400 Subject: sock: fix sendmmsg for partial sendmsg From: Soheil Hassas Yeganeh <soheil@xxxxxxxxxx> [ Upstream commit 3023898b7d4aac65987bd2f485cc22390aae6f78 ] Do not send the next message in sendmmsg for partial sendmsg invocations. sendmmsg assumes that it can continue sending the next message when the return value of the individual sendmsg invocations is positive. It results in corrupting the data for TCP, SCTP, and UNIX streams. For example, sendmmsg([["abcd"], ["efgh"]]) can result in a stream of "aefgh" if the first sendmsg invocation sends only the first byte while the second sendmsg goes through. Datagram sockets either send the entire datagram or fail, so this patch affects only sockets of type SOCK_STREAM and SOCK_SEQPACKET. Fixes: 228e548e6020 ("net: Add sendmmsg socket system call") Signed-off-by: Soheil Hassas Yeganeh <soheil@xxxxxxxxxx> Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Signed-off-by: Willem de Bruijn <willemb@xxxxxxxxxx> Signed-off-by: Neal Cardwell <ncardwell@xxxxxxxxxx> Acked-by: Maciej Żenczykowski <maze@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/socket.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/socket.c +++ b/net/socket.c @@ -2041,6 +2041,8 @@ int __sys_sendmmsg(int fd, struct mmsghd if (err) break; ++datagrams; + if (msg_data_left(&msg_sys)) + break; cond_resched(); } Patches currently in stable-queue which might be from soheil@xxxxxxxxxx are queue-4.8/net-clear-sk_err_soft-in-sk_clone_lock.patch queue-4.8/tcp-fix-return-value-for-partial-writes.patch queue-4.8/sock-fix-sendmmsg-for-partial-sendmsg.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html