[PATCH] libata: fix out-of-bounds access in pata_oldpiix.c

["David Müller" <dave.mueller@gmx.ch>]

The "pata_oldpiix" driver in linux-2.6.26 is calling its "set_dmamode" 
routine also locally, but under different preconditions as the 
corresponding call in libata-core.c. This may cause an "out-of-array 
bounds" access in "oldpiix_set_dmamode".


Signed-off-by: Dave Mueller <dave.mueller@gmx.ch>

diff -dpurN a/drivers/ata/pata_oldpiix.c b/drivers/ata/pata_oldpiix.c
--- a/drivers/ata/pata_oldpiix.c   2008-07-18 08:13:38.000000000 +0200
+++ b/drivers/ata/pata_oldpiix.c   2008-07-18 08:18:45.000000000 +0200
@@ -198,7 +198,7 @@ static unsigned int oldpiix_qc_issue(str

         if (adev != ap->private_data) {
                 oldpiix_set_piomode(ap, adev);
-               if (adev->dma_mode)
+               if (adev->dma_mode != 0xff)
                         oldpiix_set_dmamode(ap, adev);
         }
         return ata_sff_qc_issue(qc);