diff options
| author | Marcelo Roberto Jimenez <mroberto@cpti.cetuc.puc-rio.br> | 2011-02-02 16:04:02 -0200 |
|---|---|---|
| committer | John Stultz <john.stultz@linaro.org> | 2011-02-03 12:59:50 -0800 |
| commit | 83a06bf50bdf2074b9404951ff60e142d159d93b (patch) | |
| tree | ebb70cdc221d06529fd327e284f1b9191939f6aa /drivers/rtc | |
| parent | 9118626a30f8a3f58674623bebd3c34961e558af (diff) | |
| download | linux-83a06bf50bdf2074b9404951ff60e142d159d93b.tar.gz | |
RTC: Prevents a division by zero in kernel code.
This patch prevents a user space program from calling the RTC_IRQP_SET ioctl with a negative value of frequency. Also, if this call is make with a zero value of frequency, there would be a division by zero in the kernel code. [jstultz: Also initialize irq_freq to 1 to catch other divbyzero issues] CC: Alessandro Zummo <a.zummo@towertech.it> CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marcelo Roberto Jimenez <mroberto@cpti.cetuc.puc-rio.br> Signed-off-by: John Stultz <john.stultz@linaro.org>
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/class.c | 1 | ||||
| -rw-r--r-- | drivers/rtc/interface.c | 3 |
2 files changed, 4 insertions, 0 deletions
diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c index 9583cbcc6b79..c404b61386bf 100644 --- a/drivers/rtc/class.c +++ b/drivers/rtc/class.c @@ -143,6 +143,7 @@ struct rtc_device *rtc_device_register(const char *name, struct device *dev, rtc->id = id; rtc->ops = ops; rtc->owner = owner; + rtc->irq_freq = 1; rtc->max_user_freq = 64; rtc->dev.parent = dev; rtc->dev.class = rtc_class; diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c index 925006d33109..a0c01967244d 100644 --- a/drivers/rtc/interface.c +++ b/drivers/rtc/interface.c @@ -464,6 +464,9 @@ int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq) int err = 0; unsigned long flags; + if (freq <= 0) + return -EINVAL; + spin_lock_irqsave(&rtc->irq_task_lock, flags); if (rtc->irq_task != NULL && task == NULL) err = -EBUSY; |