Commit 492c8872 authored Nov 12, 2019 by Sami Tolvanen Committed by Greg Kroah-Hartman Nov 14, 2019

driver core: platform: use the correct callback type for bus_find_device

platform_find_device_by_driver calls bus_find_device and passes
platform_match as the callback function. Casting the function to a
mismatching type trips indirect call Control-Flow Integrity (CFI) checking.

This change adds a callback function with the correct type and instead
of casting the function, explicitly casts the second parameter to struct
device_driver* as expected by platform_match.

Fixes: 36f3313d ("platform: Add platform_find_device_by_driver() helper")
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191112214156.3430-1-samitolvanen@google.com

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 030cc787

drivers/base/platform.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -1310,6 +1310,11 @@ struct bus_type platform_bus_type = {
		};
		EXPORT_SYMBOL_GPL(platform_bus_type);

		static inline int __platform_match(struct device dev, const void drv)
		{
		return platform_match(dev, (struct device_driver *)drv);
		}

		/**
		* platform_find_device_by_driver - Find a platform device with a given
		* driver.
		@@ -1320,7 +1325,7 @@ struct device platform_find_device_by_driver(struct device start,
		const struct device_driver *drv)
		{
		return bus_find_device(&platform_bus_type, start, drv,
		(void *)platform_match);
		__platform_match);
		}
		EXPORT_SYMBOL_GPL(platform_find_device_by_driver);