[PATCH 6.0 0488/1073] mmc: atmel-mci: fix return value check of mmc_add_host()

Greg Kroah-Hartman
2022-12-28T15:58:08Z

From: Yang Yingliang <yangyingliang@huawei.com>

[ Upstream commit 9e6e8c43726673ca2abcaac87640b9215fd72f4c ]

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 calling mmc_free_host()
in the error path.

Fixes: 7d2be0749a59 ("atmel-mci: Driver for Atmel on-chip MMC controllers")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20221108122819.429975-1-yangyingliang@huawei.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/mmc/host/atmel-mci.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index 91d52ba7a39f..bb9bbf1c927b 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -2222,6 +2222,7 @@ static int atmci_init_slot(struct atmel_mci *host,
{
struct mmc_host *mmc;
struct atmel_mci_slot *slot;
+ int ret;

mmc = mmc_alloc_host(sizeof(struct atmel_mci_slot), &host->pdev->dev);
if (!mmc)
@@ -2305,11 +2306,13 @@ static int atmci_init_slot(struct atmel_mci *host,

host->slot[id] = slot;
mmc_regulator_get_supply(mmc);
- mmc_add_host(mmc);
+ ret = mmc_add_host(mmc);
+ if (ret) {
+ mmc_free_host(mmc);
+ return ret;
+ }

if (gpio_is_valid(slot->detect_pin)) {
- int ret;
-
timer_setup(&slot->detect_timer, atmci_detect_change, 0);

ret = request_irq(gpio_to_irq(slot->detect_pin),
--
2.35.1