From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
"Gustavo A. R. Silva" <gustavo@embeddedor.com>
Subject: [PATCH] Input: uinput - fix Spectre v1 vulnerability
Date: Tue, 16 Oct 2018 13:13:13 +0200 [thread overview]
Message-ID: <20181016111313.GA28307@embeddedor.com> (raw)
setup.code can be 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:
drivers/input/misc/uinput.c:512 uinput_abs_setup() warn: potential
spectre issue 'dev->absinfo' [w] (local cap)
Fix this by sanitizing setup.code before using it to index dev->absinfo.
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
Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
drivers/input/misc/uinput.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c
index 8ec483e..97b0809 100644
--- a/drivers/input/misc/uinput.c
+++ b/drivers/input/misc/uinput.c
@@ -42,6 +42,8 @@
#include <linux/input/mt.h>
#include "../input-compat.h"
+#include <linux/nospec.h>
+
#define UINPUT_NAME "uinput"
#define UINPUT_BUFFER_SIZE 16
#define UINPUT_NUM_REQUESTS 16
@@ -497,6 +499,7 @@ static int uinput_abs_setup(struct uinput_device *udev,
if (setup.code > ABS_MAX)
return -ERANGE;
+ setup.code = array_index_nospec(setup.code, ABS_MAX + 1);
dev = udev->dev;
--
2.7.4
next reply other threads:[~2018-10-16 11:13 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-16 11:13 Gustavo A. R. Silva [this message]
2018-10-16 17:21 ` [PATCH] Input: uinput - fix Spectre v1 vulnerability Dmitry Torokhov
2018-10-16 17:52 ` Gustavo A. R. Silva
2018-10-16 18:09 ` Dmitry Torokhov
2018-10-16 18:12 ` Gustavo A. R. Silva
2018-10-18 19:43 ` Alan Cox
2018-10-18 20:07 ` Dmitry Torokhov
2018-10-22 14:14 ` Pavel Machek
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