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authorXin Xiong <xiongx18@fudan.edu.cn>2021-10-09 12:19:18 +0800
committerUlf Hansson <ulf.hansson@linaro.org>2021-10-12 10:23:25 +0200
commit8105c2abbf36296bf38ca44f55ee45d160db476a (patch)
tree2d1e95e7ebdc14a5355ec07c087d323a660dd3db /drivers/mmc
parentf83c18cc9edc8e1a556de2d7dad956ddd9f131b9 (diff)
mmc: moxart: Fix reference count leaks in moxart_probe
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>
Diffstat (limited to 'drivers/mmc')
-rw-r--r--drivers/mmc/host/moxart-mmc.c16
1 files changed, 14 insertions, 2 deletions
diff --git a/drivers/mmc/host/moxart-mmc.c b/drivers/mmc/host/moxart-mmc.c
index 6c9d38132f74..7b9fcef490de 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);