[PATCH 6.1 0510/1146] mmc: mmci: fix return value check of mmc_add_host()

Greg Kroah-Hartman
2022-12-28T16:05:47Z

From: Yang Yingliang <yangyingliang@huawei.com>

[ Upstream commit b38a20f29a49ae04d23750d104b25400b792b98c ]

mmc_add_host() may return error, if we ignore its return value,
it will lead two issues:
1. The memory that allocated in mmc_alloc_host() is leaked.
2. In the remove() path, mmc_remove_host() will be called to
delete device, but it's not added yet, it will lead a kernel
crash because of null-ptr-deref in device_del().

So fix this by checking the return value and goto error path which
will call mmc_free_host().

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20221109133539.3275664-1-yangyingliang@huawei.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/mmc/host/mmci.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 012aa85489d8..b9e5dfe74e5c 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -2256,7 +2256,9 @@ static int mmci_probe(struct amba_device *dev,
pm_runtime_set_autosuspend_delay(&dev->dev, 50);
pm_runtime_use_autosuspend(&dev->dev);

- mmc_add_host(mmc);
+ ret = mmc_add_host(mmc);
+ if (ret)
+ goto clk_disable;

pm_runtime_put(&dev->dev);
return 0;
--
2.35.1