[PATCH 5.15 303/731] mmc: via-sdmmc: fix return value check of mmc_add_host()

Greg Kroah-Hartman
2022-12-28T15:07:27Z

From: Yang Yingliang <yangyingliang@huawei.com>

[ Upstream commit e4e46fb61e3bb4628170810d3f2b996b709b90d9 ]

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().

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

Fixes: f0bf7f61b840 ("mmc: Add new via-sdmmc host controller driver")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20221108130949.1067699-1-yangyingliang@huawei.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/mmc/host/via-sdmmc.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/via-sdmmc.c b/drivers/mmc/host/via-sdmmc.c
index 88662a90ed96..a2b0d9461665 100644
--- a/drivers/mmc/host/via-sdmmc.c
+++ b/drivers/mmc/host/via-sdmmc.c
@@ -1151,7 +1151,9 @@ static int via_sd_probe(struct pci_dev *pcidev,
pcidev->subsystem_device == 0x3891)
sdhost->quirks = VIA_CRDR_QUIRK_300MS_PWRDELAY;

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

return 0;

--
2.35.1