Commit 49036ba8 authored by Takashi Iwai's avatar Takashi Iwai Committed by Ulf Hansson
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mmc: sdhci: Clear unused bounce buffer at DMA mmap error path 



When DMA-mapping of the bounce buffer fails, the driver tries to fall
back, but it leaves the allocated host->bounce_buffer although its
size is zero.  Later on, the driver checks the use of bounce buffer
with host->bounce_buffer pointer, and it tries to use the buffer
incorrectly, resulting in Oops.

This patch clears the release the unused buffer and clears the
bounce_buffer pointer for addressing the problem.

Acked-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20210611101948.18972-1-tiwai@suse.de


Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent 2f2b73a2

drivers/mmc/host/sdhci.c

+5 −1
Original line number Diff line number Diff line
@@ -4072,9 +4072,13 @@ static void sdhci_allocate_bounce_buffer(struct sdhci_host *host) 
					   bounce_size,

					   DMA_BIDIRECTIONAL);

	ret = dma_mapping_error(mmc_dev(mmc), host->bounce_addr);

	if (ret)

	if (ret) {

		devm_kfree(mmc_dev(mmc), host->bounce_buffer);

		host->bounce_buffer = NULL;

		/* Again fall back to max_segs == 1 */

		return;

	}



	host->bounce_buffer_size = bounce_size;



	/* Lie about this since we're bouncing */