From: Marek Szyprowski m.szyprowski@samsung.com
[ 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@samsung.com Link: https://lore.kernel.org/r/20220930113408.19720-1-m.szyprowski@samsung.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/spi/spi.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 32c01e684af3..4b42f2302a8a 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1097,6 +1097,8 @@ 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; } }