From: Xin Xiong xiongx18@fudan.edu.cn
[ 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 --- drivers/mmc/host/moxart-mmc.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/host/moxart-mmc.c b/drivers/mmc/host/moxart-mmc.c index 6c9d38132f74c..7b9fcef490de7 100644 --- a/drivers/mmc/host/moxart-mmc.c +++ b/drivers/mmc/host/moxart-mmc.c @@ -621,6 +621,14 @@ 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 { @@ -675,6 +683,10 @@ 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; @@ -687,9 +699,9 @@ 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);