net: sock_diag: Fix spectre v1 gadget in __sock_diag_cmd()

req->sdiag_family is a user-controlled value that's used as an array
index. Sanitize it after the bounds check to avoid speculative
out-of-bounds array access.

This also protects the sock_is_registered() call, so this removes the
sanitize call there.

Fixes: e978de7a6d ("net: socket: Fix potential spectre v1 gadget in sock_is_registered")
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: konrad.wilk@oracle.com
Cc: jamie.iles@oracle.com
Cc: liran.alon@oracle.com
Cc: stable@vger.kernel.org
Signed-off-by: Jeremy Cline <jcline@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jeremy Cline 2018-08-13 22:23:13 +00:00 committed by David S. Miller
parent 1c89a8e3d9
commit 66b51b0a03
2 changed files with 3 additions and 2 deletions

View File

@ -10,6 +10,7 @@
#include <linux/kernel.h>
#include <linux/tcp.h>
#include <linux/workqueue.h>
#include <linux/nospec.h>
#include <linux/inet_diag.h>
#include <linux/sock_diag.h>
@ -218,6 +219,7 @@ static int __sock_diag_cmd(struct sk_buff *skb, struct nlmsghdr *nlh)
if (req->sdiag_family >= AF_MAX)
return -EINVAL;
req->sdiag_family = array_index_nospec(req->sdiag_family, AF_MAX);
if (sock_diag_handlers[req->sdiag_family] == NULL)
sock_load_diag_module(req->sdiag_family, 0);

View File

@ -2697,8 +2697,7 @@ EXPORT_SYMBOL(sock_unregister);
bool sock_is_registered(int family)
{
return family < NPROTO &&
rcu_access_pointer(net_families[array_index_nospec(family, NPROTO)]);
return family < NPROTO && rcu_access_pointer(net_families[family]);
}
static int __init sock_init(void)