[PATCH] rtc subsystem: add capability checks
Centralize CAP_SYS_XXX checks to avoid duplicate code and missing checks in
the drivers.
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c
index 07387c9..61a5825 100644
--- a/drivers/rtc/rtc-dev.c
+++ b/drivers/rtc/rtc-dev.c
@@ -214,6 +214,28 @@
struct rtc_wkalrm alarm;
void __user *uarg = (void __user *) arg;
+ /* check that the calles has appropriate permissions
+ * for certain ioctls. doing this check here is useful
+ * to avoid duplicate code in each driver.
+ */
+ switch (cmd) {
+ case RTC_EPOCH_SET:
+ case RTC_SET_TIME:
+ if (!capable(CAP_SYS_TIME))
+ return -EACCES;
+ break;
+
+ case RTC_IRQP_SET:
+ if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE))
+ return -EACCES;
+ break;
+
+ case RTC_PIE_ON:
+ if (!capable(CAP_SYS_RESOURCE))
+ return -EACCES;
+ break;
+ }
+
/* avoid conflicting IRQ users */
if (cmd == RTC_PIE_ON || cmd == RTC_PIE_OFF || cmd == RTC_IRQP_SET) {
spin_lock(&rtc->irq_task_lock);
@@ -272,9 +294,6 @@
break;
case RTC_SET_TIME:
- if (!capable(CAP_SYS_TIME))
- return -EACCES;
-
if (copy_from_user(&tm, uarg, sizeof(tm)))
return -EFAULT;
@@ -290,10 +309,6 @@
err = -EINVAL;
break;
}
- if (!capable(CAP_SYS_TIME)) {
- err = -EACCES;
- break;
- }
rtc_epoch = arg;
err = 0;
#endif