diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2018-08-15 10:50:41 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-09-26 08:36:35 +0200 |
| commit | 76b61ead8f4d913cc0493db624f3ac3ca8986a71 (patch) | |
| tree | c95b43907dac58a1557abbf554d324f5bfa749ef /drivers/misc | |
| parent | 2516ead0aaf8145c155ff7d19c32038b8de099d8 (diff) | |
misc: hmc6352: fix potential Spectre v1
commit de916736aaaadddbd6061472969f667b14204aa9 upstream.
val 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:
drivers/misc/hmc6352.c:54 compass_store() warn: potential spectre issue
'map' [r]
Fix this by sanitizing val before using it to index map
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc')
| -rw-r--r-- | drivers/misc/hmc6352.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/misc/hmc6352.c b/drivers/misc/hmc6352.c index 90520d76633f..9cde4c5bfba4 100644 --- a/drivers/misc/hmc6352.c +++ b/drivers/misc/hmc6352.c @@ -27,6 +27,7 @@ #include <linux/err.h> #include <linux/delay.h> #include <linux/sysfs.h> +#include <linux/nospec.h> static DEFINE_MUTEX(compass_mutex); @@ -50,6 +51,7 @@ static int compass_store(struct device *dev, const char *buf, size_t count, return ret; if (val >= strlen(map)) return -EINVAL; + val = array_index_nospec(val, strlen(map)); mutex_lock(&compass_mutex); ret = compass_command(c, map[val]); mutex_unlock(&compass_mutex); |