[PATCH 4.16 07/72] netlink: fix uninit-value in netlink_sendmsg

From: Greg Kroah-Hartman
Date: Mon May 14 2018 - 03:06:58 EST


4.16-stable review patch. If anyone has any objections, please let me know.

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

From: Eric Dumazet <edumazet@xxxxxxxxxx>

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@xxxxxxxxxx>
Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
net/netlink/af_netlink.c | 2 ++
1 file changed, 2 insertions(+)

--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1845,6 +1845,8 @@ static int netlink_sendmsg(struct socket

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;