Linux-mmc Archive on lore.kernel.org
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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Pan Bian <bianpan2016@163.com>,
	Ulf Hansson <ulf.hansson@linaro.org>,
	Sasha Levin <sashal@kernel.org>,
	linux-mmc@vger.kernel.org
Subject: [PATCH AUTOSEL 4.19 336/671] mmc: core: fix possible use after free of host
Date: Thu, 16 Jan 2020 11:59:34 -0500
Message-ID: <20200116170509.12787-73-sashal@kernel.org> (raw)
In-Reply-To: <20200116170509.12787-1-sashal@kernel.org>

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 f57f5de54206..dd1c14d8f686 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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Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20200116170509.12787-1-sashal@kernel.org>
2020-01-16 16:59 ` Sasha Levin [this message]
2020-01-16 17:04 ` [PATCH AUTOSEL 4.19 647/671] mmc: sdio: fix wl1251 vendor id Sasha Levin
2020-01-16 17:04 ` [PATCH AUTOSEL 4.19 648/671] mmc: core: fix wl1251 sdio quirks Sasha Levin

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