From: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> [ Upstream commit 8e9204cddcc3fea9affcfa411715ba4f66e97587 ] SPI code checks for non-zero sgt->orig_nents to determine if the buffer has been DMA-mapped. Ensure that sg_table is really zeroed after free to avoid potential NULL pointer dereference if the given SPI xfer object is reused again without being DMA-mapped. Fixes: 0c17ba73c08f ("spi: Fix cache corruption due to DMA/PIO overlap") Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> Link: https://lore.kernel.org/r/20220930113408.19720-1-m.szyprowski@xxxxxxxxxxx Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/spi/spi.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 2c616024f7c0..f595e516058c 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1047,6 +1047,8 @@ void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev, if (sgt->orig_nents) { dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir); sg_free_table(sgt); + sgt->orig_nents = 0; + sgt->nents = 0; } } -- 2.35.1