lkml.org 
[lkml]   [2015]   [May]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 3.2 108/221] spi: dw-mid: avoid potential NULL dereference
    On Tue, May 05, 2015 at 02:16:39AM +0100, Ben Hutchings wrote:
    > 3.2.69-rc1 review patch. If anyone has any objections, please let me know.
    >
    > ------------------
    >
    > From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
    >
    > commit c9dafb27c84412fe4b17c3b94cc4ffeef5df1833 upstream.
    >
    > When DMA descriptor allocation fails we should not try to assign any fields in
    > the bad descriptor. The patch adds the necessary checks for that.
    >
    > Fixes: 7063c0d942a1 (spi/dw_spi: add DMA support)
    > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
    > Signed-off-by: Mark Brown <broonie@kernel.org>
    > [bwh: Backported to 3.2: adjust context]
    > Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
    > ---
    > drivers/spi/spi-dw-mid.c | 6 ++++++
    > 1 file changed, 6 insertions(+)
    >
    > --- a/drivers/spi/spi-dw-mid.c
    > +++ b/drivers/spi/spi-dw-mid.c
    > @@ -155,6 +155,9 @@ static int mid_spi_dma_transfer(struct d
    > 1,
    > DMA_TO_DEVICE,
    > DMA_PREP_INTERRUPT | DMA_COMPL_SKIP_DEST_UNMAP);
    > + if (!txdesc)
    > + return NULL;
    > +

    This backport doesn't look right to me as the function returns an int,
    not a pointer. OTOH, it seems like this return value is not checked
    anywhere, which is why I dropped this patch in the 3.16 kernel.

    Cheers,
    --
    Luís

    > txdesc->callback = dw_spi_dma_done;
    > txdesc->callback_param = dws;
    >
    > @@ -177,6 +180,9 @@ static int mid_spi_dma_transfer(struct d
    > 1,
    > DMA_FROM_DEVICE,
    > DMA_PREP_INTERRUPT | DMA_COMPL_SKIP_DEST_UNMAP);
    > + if (!rxdesc)
    > + return NULL;
    > +
    > rxdesc->callback = dw_spi_dma_done;
    > rxdesc->callback_param = dws;
    >
    >
    > --
    > To unsubscribe from this list: send the line "unsubscribe stable" in
    > the body of a message to majordomo@vger.kernel.org
    > More majordomo info at http://vger.kernel.org/majordomo-info.html


    \
     
     \ /
      Last update: 2015-05-06 13:01    [W:6.745 / U:0.040 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site