hwmon: (applesmc) Check key count before proceeding

After reports from Chris and Josh Boyer of a rare crash in applesmc,
Guenter pointed at the initialization problem fixed below. The patch
has not been verified to fix the crash, but should be applied
regardless.

Reported-by: <jwboyer@fedoraproject.org>
Suggested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Cc: stable@vger.kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Henrik Rydberg 2013-09-26 08:33:16 +02:00 committed by Guenter Roeck
parent 4b97280675
commit 5f45138643

View File

@ -525,16 +525,25 @@ static int applesmc_init_smcreg_try(void)
{
struct applesmc_registers *s = &smcreg;
bool left_light_sensor, right_light_sensor;
unsigned int count;
u8 tmp[1];
int ret;
if (s->init_complete)
return 0;
ret = read_register_count(&s->key_count);
ret = read_register_count(&count);
if (ret)
return ret;
if (s->cache && s->key_count != count) {
pr_warn("key count changed from %d to %d\n",
s->key_count, count);
kfree(s->cache);
s->cache = NULL;
}
s->key_count = count;
if (!s->cache)
s->cache = kcalloc(s->key_count, sizeof(*s->cache), GFP_KERNEL);
if (!s->cache)