[PATCH 3.2 097/152] HID: roccat: potential out of bounds in pyra_sysfs_write_settings()

From: Ben Hutchings
Date: Mon Feb 16 2015 - 21:31:56 EST

3.2.67-rc1 review patch. If anyone has any objections, please let me know.


From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

commit 606185b20caf4c57d7e41e5a5ea4aff460aef2ab upstream.

This is a static checker fix. We write some binary settings to the
sysfs file. One of the settings is the "->startup_profile". There
isn't any checking to make sure it fits into the
pyra->profile_settings[] array in the profile_activated() function.

I added a check to pyra_sysfs_write_settings() in both places because
I wasn't positive that the other callers were correct.

Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
[bwh: Backported to 3.2: pyra_sysfs_write_settings() doesn't define a
settings variable, so write the cast-expression inline]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
drivers/hid/hid-roccat-pyra.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/hid/hid-roccat-pyra.c
+++ b/drivers/hid/hid-roccat-pyra.c
@@ -35,6 +35,8 @@ static struct class *pyra_class;
static void profile_activated(struct pyra_device *pyra,
unsigned int new_profile)
+ if (new_profile >= ARRAY_SIZE(pyra->profile_settings))
+ return;
pyra->actual_profile = new_profile;
pyra->actual_cpi = pyra->profile_settings[pyra->actual_profile].y_cpi;
@@ -303,6 +305,10 @@ static ssize_t pyra_sysfs_write_settings
if (off != 0 || count != sizeof(struct pyra_settings))
return -EINVAL;

+ if (((struct pyra_settings const *)buf)->startup_profile >=
+ ARRAY_SIZE(pyra->profile_settings))
+ return -EINVAL;
difference = memcmp(buf, &pyra->settings, sizeof(struct pyra_settings));
if (difference) {

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