[PATCH][next] mmc: moxart: Fix null pointer dereference on pointer host

From: Colin King
Date: Wed Oct 13 2021 - 06:00:58 EST


From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

There are several error return paths that dereference the null pointer
host because the pointer has not yet been set to a valid value.
Fix this by adding a new out_mmc label and exiting via this label
to avoid the host clean up and hence the null pointer dereference.

Addresses-Coverity: ("Explicit null dereference")
Fixes: 8105c2abbf36 ("mmc: moxart: Fix reference count leaks in moxart_probe")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
---
drivers/mmc/host/moxart-mmc.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/mmc/host/moxart-mmc.c b/drivers/mmc/host/moxart-mmc.c
index 7b9fcef490de..16d1c7a43d33 100644
--- a/drivers/mmc/host/moxart-mmc.c
+++ b/drivers/mmc/host/moxart-mmc.c
@@ -566,37 +566,37 @@ static int moxart_probe(struct platform_device *pdev)
if (!mmc) {
dev_err(dev, "mmc_alloc_host failed\n");
ret = -ENOMEM;
- goto out;
+ goto out_mmc;
}

ret = of_address_to_resource(node, 0, &res_mmc);
if (ret) {
dev_err(dev, "of_address_to_resource failed\n");
- goto out;
+ goto out_mmc;
}

irq = irq_of_parse_and_map(node, 0);
if (irq <= 0) {
dev_err(dev, "irq_of_parse_and_map failed\n");
ret = -EINVAL;
- goto out;
+ goto out_mmc;
}

clk = devm_clk_get(dev, NULL);
if (IS_ERR(clk)) {
ret = PTR_ERR(clk);
- goto out;
+ goto out_mmc;
}

reg_mmc = devm_ioremap_resource(dev, &res_mmc);
if (IS_ERR(reg_mmc)) {
ret = PTR_ERR(reg_mmc);
- goto out;
+ goto out_mmc;
}

ret = mmc_of_parse(mmc);
if (ret)
- goto out;
+ goto out_mmc;

host = mmc_priv(mmc);
host->mmc = mmc;
@@ -687,6 +687,7 @@ static int moxart_probe(struct platform_device *pdev)
dma_release_channel(host->dma_chan_tx);
if (!IS_ERR_OR_NULL(host->dma_chan_rx))
dma_release_channel(host->dma_chan_rx);
+out_mmc:
if (mmc)
mmc_free_host(mmc);
return ret;
--
2.32.0