mmc: atmel-mci: fix return value check of mmc_add_host()

[ 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>

diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index 807177c..6f971a3 100644 (file)
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -2223,6 +2223,7 @@ 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)
@@ -2306,11 +2307,13 @@ 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),