From 8e7dfe9c2ac8fc92859e68eb0a00f52e2f3a6ebc Mon Sep 17 00:00:00 2001 From: Amelie Delaunay Date: Wed, 4 Oct 2023 18:35:28 +0200 Subject: [PATCH] dmaengine: stm32-mdma: abort resume if no ongoing transfer commit 81337b9a72dc58a5fa0ae8a042e8cb59f9bdec4a upstream. chan->desc can be null, if transfer is terminated when resume is called, leading to a NULL pointer when retrieving the hwdesc. To avoid this case, check that chan->desc is not null and channel is disabled (transfer previously paused or terminated). Fixes: a4ffb13c8946 ("dmaengine: Add STM32 MDMA driver") Signed-off-by: Amelie Delaunay Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20231004163531.2864160-1-amelie.delaunay@foss.st.com Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman --- drivers/dma/stm32-mdma.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/dma/stm32-mdma.c b/drivers/dma/stm32-mdma.c index b9d4c843635fc..a815833a701ee 100644 --- a/drivers/dma/stm32-mdma.c +++ b/drivers/dma/stm32-mdma.c @@ -1237,6 +1237,10 @@ static int stm32_mdma_resume(struct dma_chan *c) unsigned long flags; u32 status, reg; + /* Transfer can be terminated */ + if (!chan->desc || (stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id)) & STM32_MDMA_CCR_EN)) + return -EPERM; + hwdesc = chan->desc->node[chan->curr_hwdesc].hwdesc; spin_lock_irqsave(&chan->vchan.lock, flags); -- 2.39.5