4.9-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 @@ -1795,6 +1795,8 @@ 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;