From: Marek Szyprowski Date: Fri, 30 Sep 2022 11:34:08 +0000 (+0200) Subject: spi: Ensure that sg_table won't be used after being freed X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=8e9204cddcc3fea9affcfa411715ba4f66e97587;p=kernel.git spi: Ensure that sg_table won't be used after being freed 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 Link: https://lore.kernel.org/r/20220930113408.19720-1-m.szyprowski@samsung.com Signed-off-by: Mark Brown --- diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index a4771f69f5c31..29a3098cc1573 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1102,6 +1102,8 @@ static void spi_unmap_buf_attrs(struct spi_controller *ctlr, if (sgt->orig_nents) { dma_unmap_sgtable(dev, sgt, dir, attrs); sg_free_table(sgt); + sgt->orig_nents = 0; + sgt->nents = 0; } }