From: Dan Carpenter dan.carpenter@oracle.com
commit 4f69851fbaa26b155330be35ce8ac393e93e7442 upstream.
The "used" variables here come from the user in the ioctl and it can be negative. It could result in an out of bounds write.
Signed-off-by: Dan Carpenter dan.carpenter@oracle.com Reviewed-by: Chris Wilson chris@chris-wilson.co.uk Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Link: https://patchwork.freedesktop.org/patch/msgid/20191004102251.GC823@mwanda Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/i810/i810_dma.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/i810/i810_dma.c +++ b/drivers/gpu/drm/i810/i810_dma.c @@ -728,7 +728,7 @@ static void i810_dma_dispatch_vertex(str if (nbox > I810_NR_SAREA_CLIPRECTS) nbox = I810_NR_SAREA_CLIPRECTS;
- if (used > 4 * 1024) + if (used < 0 || used > 4 * 1024) used = 0;
if (sarea_priv->dirty) @@ -1048,7 +1048,7 @@ static void i810_dma_dispatch_mc(struct if (u != I810_BUF_CLIENT) DRM_DEBUG("MC found buffer that isn't mine!\n");
- if (used > 4 * 1024) + if (used < 0 || used > 4 * 1024) used = 0;
sarea_priv->dirty = 0x7f;