From: Anton Blanchard <anton@samba.org>
Date: Tue, 17 May 2011 19:38:57 +0000 (-0400)
Subject: net: recvmmsg: Strip MSG_WAITFORONE when calling recvmsg
X-Git-Url: http://git.alex.org.uk

net: recvmmsg: Strip MSG_WAITFORONE when calling recvmsg

BugLink: http://bugs.launchpad.net/bugs/793702

commit b9eb8b8752804cecbacdb4d24b52e823cf07f107 upstream.

recvmmsg fails on a raw socket with EINVAL. The reason for this is
packet_recvmsg checks the incoming flags:

        err = -EINVAL;
        if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
                goto out;

This patch strips out MSG_WAITFORONE when calling recvmmsg which
fixes the issue.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
---

diff --git a/net/socket.c b/net/socket.c
index 29c7df0..1204afd 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2117,14 +2117,16 @@ int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen,
 		 */
 		if (MSG_CMSG_COMPAT & flags) {
 			err = __sys_recvmsg(sock, (struct msghdr __user *)compat_entry,
-					    &msg_sys, flags, datagrams);
+					    &msg_sys, flags & ~MSG_WAITFORONE,
+					    datagrams);
 			if (err < 0)
 				break;
 			err = __put_user(err, &compat_entry->msg_len);
 			++compat_entry;
 		} else {
 			err = __sys_recvmsg(sock, (struct msghdr __user *)entry,
-					    &msg_sys, flags, datagrams);
+					    &msg_sys, flags & ~MSG_WAITFORONE,
+					    datagrams);
 			if (err < 0)
 				break;
 			err = put_user(err, &entry->msg_len);