mmc: moxart: Fix reference count leaks in moxart_probe

[ Upstream commit 8105c2abbf36296bf38ca44f55ee45d160db476a ]

The issue happens in several error handling paths on two refcounted
object related to the object "host" (dma_chan_rx, dma_chan_tx). In
these paths, the function forgets to decrement one or both objects'
reference count increased earlier by dma_request_chan(), causing
reference count leaks.

Fix it by balancing the refcounts of both objects in some error
handling paths. In correspondence with the changes in moxart_probe(),
IS_ERR() is replaced with IS_ERR_OR_NULL() in moxart_remove() as well.

Signed-off-by: Xin Xiong <xiongx18@fudan.edu.cn>
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Link: https://lore.kernel.org/r/20211009041918.28419-1-xiongx18@fudan.edu.cn
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Xin Xiong 2021-10-09 12:19:18 +08:00 committed by Greg Kroah-Hartman
parent 38608d32ad
commit 219df0f6ba

View File

@ -624,6 +624,14 @@ static int moxart_probe(struct platform_device *pdev)
ret = -EPROBE_DEFER;
goto out;
}
if (!IS_ERR(host->dma_chan_tx)) {
dma_release_channel(host->dma_chan_tx);
host->dma_chan_tx = NULL;
}
if (!IS_ERR(host->dma_chan_rx)) {
dma_release_channel(host->dma_chan_rx);
host->dma_chan_rx = NULL;
}
dev_dbg(dev, "PIO mode transfer enabled\n");
host->have_dma = false;
} else {
@ -678,6 +686,10 @@ static int moxart_probe(struct platform_device *pdev)
return 0;
out:
if (!IS_ERR_OR_NULL(host->dma_chan_tx))
dma_release_channel(host->dma_chan_tx);
if (!IS_ERR_OR_NULL(host->dma_chan_rx))
dma_release_channel(host->dma_chan_rx);
if (mmc)
mmc_free_host(mmc);
return ret;
@ -690,9 +702,9 @@ static int moxart_remove(struct platform_device *pdev)
dev_set_drvdata(&pdev->dev, NULL);
if (!IS_ERR(host->dma_chan_tx))
if (!IS_ERR_OR_NULL(host->dma_chan_tx))
dma_release_channel(host->dma_chan_tx);
if (!IS_ERR(host->dma_chan_rx))
if (!IS_ERR_OR_NULL(host->dma_chan_rx))
dma_release_channel(host->dma_chan_rx);
mmc_remove_host(mmc);
mmc_free_host(mmc);