From: Marek Szyprowski <m.szyprowski@samsung.com> stable inclusion from stable-v5.10.150 commit d9e25dc053f6114d3fb5dca0e52409778e28acbc category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I6D0XA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ 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> Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com> --- drivers/spi/spi.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 6ea7b286c80c..857a1399850c 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -946,6 +946,8 @@ 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; } } -- 2.25.1