mmc: moxart: Fix null pointer dereference on pointer host

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@canonical.com>
Link: https://lore.kernel.org/r/20211013100052.125461-1-colin.king@canonical.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/moxart-mmc.c b/drivers/mmc/host/moxart-mmc.c
index 7b9fcef490de77eda5846d102d05dc7c51376422..16d1c7a43d331938e2c8fb0513eede9129776a69 100644 (file)
--- 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 @@ out:
                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;