[PATCH 4.15 128/168] netlink: make sure nladdr has correct size in netlink_connect()

From: Greg Kroah-Hartman
Date: Tue Apr 10 2018 - 19:17:48 EST


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

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

From: Alexander Potapenko <glider@xxxxxxxxxx>


[ Upstream commit 7880287981b60a6808f39f297bb66936e8bdf57a ]

KMSAN reports use of uninitialized memory in the case when |alen| is
smaller than sizeof(struct sockaddr_nl), and therefore |nladdr| isn't
fully copied from the userspace.

Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx>
Fixes: 1da177e4c3f41524 ("Linux-2.6.12-rc2")
Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/netlink/af_netlink.c | 3 +++
1 file changed, 3 insertions(+)

--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1052,6 +1052,9 @@ static int netlink_connect(struct socket
if (addr->sa_family != AF_NETLINK)
return -EINVAL;

+ if (alen < sizeof(struct sockaddr_nl))
+ return -EINVAL;
+
if ((nladdr->nl_groups || nladdr->nl_pid) &&
!netlink_allowed(sock, NL_CFG_F_NONROOT_SEND))
return -EPERM;