linux-kernel - [PATCH 01/11] rtc: mxc: Initialize drvdata before registering device

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1304731254-3238-2-git-send-email-john.stultz@linaro.org>
Date:	Fri,  6 May 2011 18:20:44 -0700
From:	John Stultz <john.stultz@...aro.org>
To:	lkml <linux-kernel@...r.kernel.org>
Cc:	Wolfram Sang <w.sang@...gutronix.de>,
	Alessandro Zummo <a.zummo@...ertech.it>,
	Thomas Gleixner <tglx@...utronix.de>,
	rtc-linux@...glegroups.com, John Stultz <john.stultz@...aro.org>
Subject: [PATCH 01/11] rtc: mxc: Initialize drvdata before registering device

From: Wolfram Sang <w.sang@...gutronix.de>

Commit f44f7f96a20 ("RTC: Initialize kernel state from RTC") uncovered
an issue in a number of RTC drivers, where the drivers call
rtc_device_register before initializing the device or platform drvdata.

This frequently results in null pointer dereferences when the
rtc_device_register immediately makes use of the rtc device, calling
rtc_read_alarm.

The solution is to ensure the drvdata is initialized prior to registering
the rtc device.

CC: Alessandro Zummo <a.zummo@...ertech.it>
CC: Thomas Gleixner <tglx@...utronix.de>
CC: rtc-linux@...glegroups.com
Signed-off-by: Wolfram Sang <w.sang@...gutronix.de>
[fixed up commit log -jstultz]
Signed-off-by: John Stultz <john.stultz@...aro.org>
---
 drivers/rtc/rtc-mxc.c |   19 +++++++++++--------
 1 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/rtc/rtc-mxc.c b/drivers/rtc/rtc-mxc.c
index 826ab64..d814417 100644
--- a/drivers/rtc/rtc-mxc.c
+++ b/drivers/rtc/rtc-mxc.c
@@ -418,14 +418,6 @@ static int __init mxc_rtc_probe(struct platform_device *pdev)
 		goto exit_put_clk;
 	}
 
-	rtc = rtc_device_register(pdev->name, &pdev->dev, &mxc_rtc_ops,
-				  THIS_MODULE);
-	if (IS_ERR(rtc)) {
-		ret = PTR_ERR(rtc);
-		goto exit_put_clk;
-	}
-
-	pdata->rtc = rtc;
 	platform_set_drvdata(pdev, pdata);
 
 	/* Configure and enable the RTC */
@@ -438,8 +430,19 @@ static int __init mxc_rtc_probe(struct platform_device *pdev)
 		pdata->irq = -1;
 	}
 
+	rtc = rtc_device_register(pdev->name, &pdev->dev, &mxc_rtc_ops,
+				  THIS_MODULE);
+	if (IS_ERR(rtc)) {
+		ret = PTR_ERR(rtc);
+		goto exit_clr_drvdata;
+	}
+
+	pdata->rtc = rtc;
+
 	return 0;
 
+exit_clr_drvdata:
+	platform_set_drvdata(pdev, NULL);
 exit_put_clk:
 	clk_disable(pdata->clk);
 	clk_put(pdata->clk);
-- 
1.7.3.2.146.gca209

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/