diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2018-08-15 16:14:37 +0300 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2018-12-17 01:08:53 +0300 |
| commit | 25992c86367b78adbe78464fb85083da1b289b43 (patch) | |
| tree | a2c991d40c34ba40a81c21a9dbbef28d7ae75df8 | |
| parent | 8d5761d774afccc0e5056047ddac7bb58f314948 (diff) | |
| download | linux-25992c86367b78adbe78464fb85083da1b289b43.tar.xz | |
hwmon: (nct6775) Fix potential Spectre v1
commit d49dbfade96d5b0863ca8a90122a805edd5ef50a upstream.
val 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:
vers/hwmon/nct6775.c:2698 store_pwm_weight_temp_sel() warn: potential
spectre issue 'data->temp_src' [r]
Fix this by sanitizing val before using it to index data->temp_src
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: Guenter Roeck <linux@roeck-us.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | drivers/hwmon/nct6775.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/hwmon/nct6775.c b/drivers/hwmon/nct6775.c index a720a75fd5a6..2b6bbae6aa25 100644 --- a/drivers/hwmon/nct6775.c +++ b/drivers/hwmon/nct6775.c @@ -57,6 +57,7 @@ #include <linux/mutex.h> #include <linux/acpi.h> #include <linux/io.h> +#include <linux/nospec.h> #include "lm75.h" #define USE_ALTERNATE @@ -2438,6 +2439,7 @@ store_pwm_weight_temp_sel(struct device *dev, struct device_attribute *attr, return err; if (val > NUM_TEMP) return -EINVAL; + val = array_index_nospec(val, NUM_TEMP + 1); if (val && (!(data->have_temp & (1 << (val - 1))) || !data->temp_src[val - 1])) return -EINVAL; |