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: 1da177e ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <[email protected]> Reported-by: syzbot <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
klaby · May 16, 2018 · 473ac55 · 473ac55
1 parent 7b38b6d
commit 473ac55
Showing 1 changed file with 2 additions and 0 deletions.
diff --git 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;