4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Amelie Delaunay amelie.delaunay@foss.st.com
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.c... Signed-off-by: Vinod Koul vkoul@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/dma/stm32-mdma.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/drivers/dma/stm32-mdma.c +++ b/drivers/dma/stm32-mdma.c @@ -1217,6 +1217,10 @@ static int stm32_mdma_resume(struct dma_ 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);