net: socket: Fix potential spectre v1 gadget in sock_is_registered

'family' can be a user-controlled value, so sanitize it after the bounds check to avoid speculative out-of-bounds access. Cc: Josh Poimboeuf <[email protected]> Cc: [email protected] Signed-off-by: Jeremy Cline <[email protected]> Signed-off-by: David S. Miller <[email protected]>
ambv · Jul 29, 2018 · e978de7 · e978de7
1 parent c8e8cd5
commit e978de7
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/net/socket.c b/net/socket.c
@@ -2690,7 +2690,8 @@ EXPORT_SYMBOL(sock_unregister);
 
 bool sock_is_registered(int family)
 {
-	return family < NPROTO && rcu_access_pointer(net_families[family]);
+	return family < NPROTO &&
+		rcu_access_pointer(net_families[array_index_nospec(family, NPROTO)]);
 }
 
 static int __init sock_init(void)