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| author | Xi Wang <xi.wang@gmail.com> | 2011-11-23 01:12:01 -0500 |
|---|---|---|
| committer | Dave Airlie <airlied@redhat.com> | 2011-11-23 08:59:28 +0000 |
| commit | a5cd335165e31db9dbab636fd29895d41da55dd2 (patch) | |
| tree | 4d01d5801047b466c44c40231773e66a9dfb704d | |
| parent | c916874d60d9daf2e2d5f4f622b185ef57deb6a4 (diff) | |
| download | blackbird-op-linux-a5cd335165e31db9dbab636fd29895d41da55dd2.tar.gz blackbird-op-linux-a5cd335165e31db9dbab636fd29895d41da55dd2.zip | |
drm: integer overflow in drm_mode_dirtyfb_ioctl()
There is a potential integer overflow in drm_mode_dirtyfb_ioctl()
if userspace passes in a large num_clips. The call to kmalloc would
allocate a small buffer, and the call to fb->funcs->dirty may result
in a memory corruption.
Reported-by: Haogang Chen <haogangchen@gmail.com>
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
| -rw-r--r-- | drivers/gpu/drm/drm_crtc.c | 4 | ||||
| -rw-r--r-- | include/drm/drm_mode.h | 2 |
2 files changed, 6 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index 405c63b9d539..8323fc389840 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -1873,6 +1873,10 @@ int drm_mode_dirtyfb_ioctl(struct drm_device *dev, } if (num_clips && clips_ptr) { + if (num_clips < 0 || num_clips > DRM_MODE_FB_DIRTY_MAX_CLIPS) { + ret = -EINVAL; + goto out_err1; + } clips = kzalloc(num_clips * sizeof(*clips), GFP_KERNEL); if (!clips) { ret = -ENOMEM; diff --git a/include/drm/drm_mode.h b/include/drm/drm_mode.h index d30bedfeb7ef..ddd46db65b57 100644 --- a/include/drm/drm_mode.h +++ b/include/drm/drm_mode.h @@ -235,6 +235,8 @@ struct drm_mode_fb_cmd { #define DRM_MODE_FB_DIRTY_ANNOTATE_FILL 0x02 #define DRM_MODE_FB_DIRTY_FLAGS 0x03 +#define DRM_MODE_FB_DIRTY_MAX_CLIPS 256 + /* * Mark a region of a framebuffer as dirty. * |
