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authorGustavo A. R. Silva <gustavo@embeddedor.com>2018-12-21 15:47:53 -0600
committerDavid S. Miller <davem@davemloft.net>2018-12-22 15:09:25 -0800
commita95386f0390ab602904d11fe6bd7ea5ef9b136f8 (patch)
tree2468c24c4cfbe9c94218153587273bdd7ec9493b /net
parentd686026b1e6ed4ea27d630d8f54f9a694db088b2 (diff)
nfc: af_nfc: Fix Spectre v1 vulnerability
proto 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/nfc/af_nfc.c:42 nfc_sock_create() warn: potential spectre issue 'proto_tab' [w] (local cap) Fix this by sanitizing proto 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')
-rw-r--r--net/nfc/af_nfc.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/net/nfc/af_nfc.c b/net/nfc/af_nfc.c
index d3e594eb36d0..256f3c57059e 100644
--- a/net/nfc/af_nfc.c
+++ b/net/nfc/af_nfc.c
@@ -21,6 +21,7 @@
#include <linux/nfc.h>
#include <linux/module.h>
+#include <linux/nospec.h>
#include "nfc.h"
@@ -37,6 +38,7 @@ static int nfc_sock_create(struct net *net, struct socket *sock, int proto,
if (proto < 0 || proto >= NFC_SOCKPROTO_MAX)
return -EINVAL;
+ proto = array_index_nospec(proto, NFC_SOCKPROTO_MAX);
read_lock(&proto_tab_lock);
if (proto_tab[proto] && try_module_get(proto_tab[proto]->owner)) {

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