| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.19 351/639] mmc: core: fix possible use after free of host | Date | Fri, 24 Jan 2020 10:28:41 +0100 |
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From: Pan Bian <bianpan2016@163.com>
[ 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: 1ed217194488 ("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> --- drivers/mmc/core/host.c | 2 -- 1 file changed, 2 deletions(-)
diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c index f57f5de542064..dd1c14d8f6863 100644 --- a/drivers/mmc/core/host.c +++ b/drivers/mmc/core/host.c @@ -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; } -- 2.20.1
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