diff options
| author | Dan Carpenter <dan.carpenter@oracle.com> | 2019-10-04 13:22:51 +0300 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2019-10-04 19:04:05 +0300 |
| commit | 4f69851fbaa26b155330be35ce8ac393e93e7442 (patch) | |
| tree | 986759e104e9cac00e6628b4080abdf4630b9b39 | |
| parent | ba2a1c8706151ac3234d2d020873feab498ab1bb (diff) | |
| download | linux-4f69851fbaa26b155330be35ce8ac393e93e7442.tar.xz | |
drm/i810: Prevent underflow in ioctl
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
| -rw-r--r-- | drivers/gpu/drm/i810/i810_dma.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i810/i810_dma.c b/drivers/gpu/drm/i810/i810_dma.c index 2a77823b8e9a..e66c38332df4 100644 --- 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(struct drm_device *dev, 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 drm_device *dev, struct drm_buf *buf, in 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; |