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Commit 05e2408d authored by Ossama Othman's avatar Ossama Othman Committed by Greg Kroah-Hartman
Browse files

memrar: Address kernel oops during resource cleanup 



Some delayed initialization is performed in this driver.  Make sure
resources that are used during driver clean-up (e.g. during driver's
release() function) are fully initialized before first use.  This is
particularly important for the case when the delayed initialization
isn't completed, leaving behind a partially initialized driver.

Such a scenario can occur when RAR is not available on the platform,
and the driver is release()d.

Signed-off-by: default avatarOssama Othman <ossama.othman@intel.com>
Signed-off-by: default avatarAlan Cox <alan@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 4cae2597

drivers/staging/memrar/memrar_handler.c

+19 −9
Original line number Diff line number Diff line
@@ -279,15 +279,6 @@ static int memrar_init_rar_resources(int rarnum, char const *devname) 
	BUG_ON(!memrar_is_valid_rar_type(rarnum));

	BUG_ON(rar->allocated);



	mutex_init(&rar->lock);



	/*

	 * Initialize the process table before we reach any

	 * code that exit on failure since the finalization

	 * code requires an initialized list.

	 */

	INIT_LIST_HEAD(&rar->buffers.list);



	if (rar_get_address(rarnum, &low, &high) != 0)

		/* No RAR is available. */

		return -ENODEV;
@@ -941,9 +932,28 @@ static int memrar_registration_callback(unsigned long rar) 
static int __init memrar_init(void)

{

	int err;

	int i;



	printk(banner);



	/*

	 * Some delayed initialization is performed in this driver.

	 * Make sure resources that are used during driver clean-up

	 * (e.g. during driver's release() function) are fully

	 * initialized before first use.  This is particularly

	 * important for the case when the delayed initialization

	 * isn't completed, leaving behind a partially initialized

	 * driver.

	 *

	 * Such a scenario can occur when RAR is not available on the

	 * platform, and the driver is release()d.

	 */

	for (i = 0; i != ARRAY_SIZE(memrars); ++i) {

		struct memrar_rar_info * const rar = &memrars[i];

		mutex_init(&rar->lock);

		INIT_LIST_HEAD(&rar->buffers.list);

	}



	err = misc_register(&memrar_miscdev);

	if (err)

		return err;