From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stepan Moskovchenko Subject: [PATCH v2] of: Deep-copy names of platform devices Date: Tue, 12 Aug 2014 19:30:37 -0700 Message-ID: <1407897037-6037-1-git-send-email-stepanm@codeaurora.org> References: <53EAC37C.4020203@codeaurora.org> Return-path: In-Reply-To: <53EAC37C.4020203@codeaurora.org> Sender: linux-arm-msm-owner@vger.kernel.org To: grant.likely@linaro.org, robh+dt@kernel.org, devicetree@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, stepanm@codeaurora.org List-Id: devicetree@vger.kernel.org When we parse the device tree and allocate platform devices, the 'name' of the newly-created platform_device is set to point to the 'name' field of the 'struct device' embedded within the platform_device. This is dangerous, because the name of the 'struct device' is dynamically allocated. Drivers may call dev_set_name() on the device, which will free and reallocate the name of the device, leaving the 'name' of the platform_device pointing to the now-freed memory. Furthermore, if the dev_set_name() call is made from a driver's probe() function and a subsequent request results in probe deferral, the dangling 'name' reference may lead to the device being re-probed using the wrong driver. To mitigate these scenarios, we use kstrdup to perform a deep copy of the device name when assigning the name of the platform_device, so that the platform_device name is unaffected by any calls to dev_set_name() that might made by drivers to rename the embedded 'struct device'. Signed-off-by: Stepan Moskovchenko --- * v2 - swap cleanup order drivers/of/device.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/of/device.c b/drivers/of/device.c index f685e55..e9beae6 100644 --- a/drivers/of/device.c +++ b/drivers/of/device.c @@ -54,7 +54,7 @@ int of_device_add(struct platform_device *ofdev) /* name and id have to be set so that the platform bus doesn't get * confused on matching */ - ofdev->name = dev_name(&ofdev->dev); + ofdev->name = kstrdup(dev_name(&ofdev->dev), GFP_KERNEL); ofdev->id = -1; /* device_add will assume that this device is on the same node as @@ -75,6 +75,7 @@ EXPORT_SYMBOL(of_device_register); void of_device_unregister(struct platform_device *ofdev) { + kfree(ofdev->name); device_unregister(&ofdev->dev); } EXPORT_SYMBOL(of_device_unregister); -- The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation