Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754795Ab1BBSER (ORCPT ); Wed, 2 Feb 2011 13:04:17 -0500 Received: from mail-gw0-f46.google.com ([74.125.83.46]:41948 "EHLO mail-gw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754547Ab1BBSEQ (ORCPT ); Wed, 2 Feb 2011 13:04:16 -0500 From: Marcelo Roberto Jimenez To: mroberto@cpti.cetuc.puc-rio.br, a.zummo@towertech.it, john.stultz@linaro.org Cc: rtc-linux@googlegroups.com, linux-kernel@vger.kernel.org Subject: [PATCH] RTC: Prevents a division by zero in kernel code. Date: Wed, 2 Feb 2011 16:04:02 -0200 Message-Id: <1296669842-32611-1-git-send-email-mroberto@cpti.cetuc.puc-rio.br> X-Mailer: git-send-email 1.7.3.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1088 Lines: 32 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. Signed-off-by: Marcelo Roberto Jimenez --- drivers/rtc/interface.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c index 925006d..a0c0196 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; -- 1.7.3.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/