diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2018-08-15 08:14:37 -0500 |
|---|---|---|
| committer | Guenter Roeck <linux@roeck-us.net> | 2018-08-26 17:45:25 -0700 |
| commit | d49dbfade96d5b0863ca8a90122a805edd5ef50a (patch) | |
| tree | 730c6cb452f851db3274f9397798c6ea47fd25a0 | |
| parent | f196dec6d50abb2e65fb54a0621b2f1b4d922995 (diff) | |
| download | linux-d49dbfade96d5b0863ca8a90122a805edd5ef50a.tar.gz | |
hwmon: (nct6775) Fix potential Spectre v1
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
Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
| -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 c6bd61e4695abc..944f5b63aecd70 100644 --- a/drivers/hwmon/nct6775.c +++ b/drivers/hwmon/nct6775.c @@ -63,6 +63,7 @@ #include <linux/bitops.h> #include <linux/dmi.h> #include <linux/io.h> +#include <linux/nospec.h> #include "lm75.h" #define USE_ALTERNATE @@ -2689,6 +2690,7 @@ 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 & BIT(val - 1)) || !data->temp_src[val - 1])) return -EINVAL; |