Commit 92b633a8 authored Nov 30, 2014 by Ard Biesheuvel Committed by Brian Norris Dec 12, 2014

mtd: physmap_of: fix potential NULL dereference



On device remove, when testing the cmtd field of an of_flash
struct to decide whether it is a concatenated device or not,
we get a false positive on cmtd == NULL, and dereference it
subsequently. This may occur if of_flash_remove() is called
from the cleanup path of of_flash_probe().

Instead, test for NULL first, and only then perform the test
for a concatenated device.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

parent 58c81957

drivers/mtd/maps/physmap_of.c

+3 −5

Original line number	Diff line number	Diff line
		@@ -47,14 +47,12 @@ static int of_flash_remove(struct platform_device *dev)
		return 0;
		dev_set_drvdata(&dev->dev, NULL);

		if (info->cmtd != info->list[0].mtd) {
		if (info->cmtd) {
		mtd_device_unregister(info->cmtd);
		if (info->cmtd != info->list[0].mtd)
		mtd_concat_destroy(info->cmtd);
		}

		if (info->cmtd)
		mtd_device_unregister(info->cmtd);

		for (i = 0; i < info->list_size; i++) {
		if (info->list[i].mtd)
		map_destroy(info->list[i].mtd);