diff options
| author | Xi Wang <xi.wang@gmail.com> | 2011-11-23 01:12:01 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-12-09 08:52:20 -0800 |
| commit | 61aff74833b86c735ee901c1038f0cbfcd606ae7 (patch) | |
| tree | 9c05d7c1ca3eaba38dc2264b2181fa07767a62b3 | |
| parent | e84ce11bd0183328e00accb611893b9a819dc0ba (diff) | |
drm: integer overflow in drm_mode_dirtyfb_ioctl()
commit a5cd335165e31db9dbab636fd29895d41da55dd2 upstream.
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>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -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 82db18506662..1367ced8c26d 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -1866,6 +1866,10 @@ 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 c4961ea50a49..53dfa1098b98 100644 --- a/include/drm/drm_mode.h +++ b/include/drm/drm_mode.h @@ -233,6 +233,8 @@ 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. * |