Patch "net: initialize msg.msg_flags in recvfrom" has been added to the 4.4-stable tree

Patch "net: initialize msg.msg_flags in recvfrom" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    net: initialize msg.msg_flags in recvfrom

to the 4.4-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:
     net-initialize-msg.msg_flags-in-recvfrom.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Mon Dec 18 14:47:43 CET 2017
From: Alexander Potapenko <glider@google.com>
Date: Wed, 8 Mar 2017 18:08:16 +0100
Subject: net: initialize msg.msg_flags in recvfrom

From: Alexander Potapenko <glider@google.com>


[ Upstream commit 9f138fa609c47403374a862a08a41394be53d461 ]

KMSAN reports a use of uninitialized memory in put_cmsg() because
msg.msg_flags in recvfrom haven't been initialized properly.
The flag values don't affect the result on this path, but it's still a
good idea to initialize them explicitly.

Signed-off-by: Alexander Potapenko <glider@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/socket.c |    1 +
 1 file changed, 1 insertion(+)

--- a/net/socket.c
+++ b/net/socket.c
@@ -1697,6 +1697,7 @@ SYSCALL_DEFINE6(recvfrom, int, fd, void
 	/* We assume all kernel code knows the size of sockaddr_storage */
 	msg.msg_namelen = 0;
 	msg.msg_iocb = NULL;
+	msg.msg_flags = 0;
 	if (sock->file->f_flags & O_NONBLOCK)
 		flags |= MSG_DONTWAIT;
 	err = sock_recvmsg(sock, &msg, iov_iter_count(&msg.msg_iter), flags);


Patches currently in stable-queue which might be from glider@google.com are

queue-4.4/net-initialize-msg.msg_flags-in-recvfrom.patch