path: root/net
diff options
authorGustavo A. R. Silva <gustavo@embeddedor.com>2018-12-21 15:22:29 -0600
committerDavid S. Miller <davem@davemloft.net>2018-12-22 18:41:58 -0800
commita3ac5817ffe8f81dbe6be1522b499b48bc322e3a (patch)
tree43411ab4065691f005e57aae92d736debc393989 /net
parent6b8d95f1795c42161dc0984b6863e95d6acf24ed (diff)
can: af_can: Fix Spectre v1 vulnerability
protocol is indirectly controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. This issue was detected with the help of Smatch: net/can/af_can.c:115 can_get_proto() warn: potential spectre issue 'proto_tab' [w] Fix this by sanitizing protocol before using it to index proto_tab. Notice that given that speculation windows are large, the policy is to kill the speculation on the first load and not worry if it can be completed with a dependent load/store [1]. [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2 Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
1 files changed, 2 insertions, 0 deletions
diff --git a/net/can/af_can.c b/net/can/af_can.c
index 1684ba5b51eb..cade7250c6d4 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -59,6 +59,7 @@
#include <linux/can/core.h>
#include <linux/can/skb.h>
#include <linux/ratelimit.h>
+#include <linux/nospec.h>
#include <net/net_namespace.h>
#include <net/sock.h>
@@ -136,6 +137,7 @@ static int can_create(struct net *net, struct socket *sock, int protocol,
if (protocol < 0 || protocol >= CAN_NPROTO)
return -EINVAL;
+ protocol = array_index_nospec(protocol, CAN_NPROTO);
cp = can_get_proto(protocol);

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