mmc: core: fix possible use after free of host

[ Upstream commit 8e1943af2986db42bee2b8dddf49a36cdb2e9219 ]

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: 1ed2171944 ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Pan Bian 2019-04-17 16:28:37 +08:00 committed by Greg Kroah-Hartman
parent efe0c19618
commit 9dd9716052

View File

@ -385,8 +385,6 @@ 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;
}