Commit 8e1943af authored Apr 17, 2019 by Pan Bian Committed by Ulf Hansson May 06, 2019

mmc: core: fix possible use after free of host



In the function mmc_alloc_host, the function put_device is called to
release allocated resources when mmc_gpio_alloc fails. Finally, the
function pointed by host->class_dev.class->dev_release (i.e.,
mmc_host_classdev_release) is used to release resources including the
host structure. However, after put_device, host is used and released
again. Resulting in a use-after-free bug.

Fixes: 1ed21719 ("mmc: core: fix error path in mmc_host_alloc")
Signed-off-by: Pan Bian <bianpan2016@163.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

parent 42c38d4a

drivers/mmc/core/host.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -429,8 +429,6 @@ struct mmc_host mmc_alloc_host(int extra, struct device dev)

		if (mmc_gpio_alloc(host)) {
		put_device(&host->class_dev);
		ida_simple_remove(&mmc_host_ida, host->index);
		kfree(host);
		return NULL;
		}

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