[PATCH 3.16 119/366] netlink: fix uninit-value in netlink_sendmsg

[Ben Hutchings]

3.16.60-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Eric Dumazet <eduma...@google.com>

commit 6091f09c2f79730d895149bcfe3d66140288cd0e upstream.

syzbot reported :

BUG: KMSAN: uninit-value in ffs arch/x86/include/asm/bitops.h:432 [inline]
BUG: KMSAN: uninit-value in netlink_sendmsg+0xb26/0x1310 
net/netlink/af_netlink.c:1851

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <eduma...@google.com>
Reported-by: syzbot <syzkal...@googlegroups.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
 net/netlink/af_netlink.c | 2 ++
 1 file changed, 2 insertions(+)

--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1658,6 +1658,8 @@ static int netlink_sendmsg(struct kiocb
 
        if (msg->msg_namelen) {
                err = -EINVAL;
+               if (msg->msg_namelen < sizeof(struct sockaddr_nl))
+                       goto out;
                if (addr->nl_family != AF_NETLINK)
                        goto out;
                dst_portid = addr->nl_pid;