lkml.org 
[lkml]   [2022]   [Oct]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 6.0 333/862] spi: Ensure that sg_table wont be used after being freed
    Date
    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;
    }
    }

    --
    2.35.1


    \
     
     \ /
      Last update: 2022-10-19 11:03    [W:4.127 / U:0.064 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site