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: e978de7a6d38 ("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 ---
Since commit e978de7a6d38 didn't apply cleanly to v4.14, this won't either since it reverts that change. To apply cleanly there, the change to sock_is_registered() needs to be dropped.
net/core/sock_diag.c | 2 ++ net/socket.c | 3 +-- 2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/net/core/sock_diag.c b/net/core/sock_diag.c index c37b5be7c5e4..3312a5849a97 100644 --- a/net/core/sock_diag.c +++ b/net/core/sock_diag.c @@ -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); diff --git a/net/socket.c b/net/socket.c index 53c907169818..391a0da49ffe 100644 --- a/net/socket.c +++ b/net/socket.c @@ -2679,8 +2679,7 @@ 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)