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dmaengine: stm32-mdma: abort resume if no ongoing transfer

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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 <amelie.delaunay@foss.st.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20231004163531.2864160-1-amelie.delaunay@foss.st.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Amelie Delaunay 2023-10-04 18:35:28 +02:00 • committed by Ksawlii
parent 594c98c053
commit 7ceb2a59aa
1 changed files with 4 additions and 0 deletions
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4
drivers/dma/stm32-mdma.c
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@ -1206,6 +1206,10 @@ static int stm32_mdma_resume(struct dma_chan *c)
unsigned long flags; unsigned long flags;
u32 status, reg; 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; hwdesc = chan->desc->node[chan->curr_hwdesc].hwdesc;
spin_lock_irqsave(&chan->vchan.lock, flags); spin_lock_irqsave(&chan->vchan.lock, flags);