From 49036ba889e346da6ebf2f741fe0b0ee49a11b08 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Fri, 11 Jun 2021 12:19:48 +0200 Subject: 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: Adrian Hunter Signed-off-by: Takashi Iwai Link: https://lore.kernel.org/r/20210611101948.18972-1-tiwai@suse.de Signed-off-by: Ulf Hansson --- drivers/mmc/host/sdhci.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'drivers/mmc') diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 6aaf5c3ce34c..cf01b6f94d7f 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -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 */ -- cgit v1.2.3