From: Eric Dumazet <edumazet@google.com>
Date: Sat, 7 Apr 2018 20:42:37 +0000 (-0700)
Subject: netlink: fix uninit-value in netlink_sendmsg
X-Git-Tag: v4.9.100~32
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=473ac55c5e036a73455bfbf5bf7b7bffeac4fa3d;p=platform%2Fkernel%2Flinux-amlogic.git

netlink: fix uninit-value in netlink_sendmsg

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 <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 1e97b8d..15e6e7b 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1795,6 +1795,8 @@ static int netlink_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
 
 	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;