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| author | Xi Wang <xi.wang@gmail.com> | 2011-11-23 01:12:01 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-12-09 08:54:06 -0800 |
| commit | 02a04b98adead5626a395edc21bf6d7f17611938 (patch) | |
| tree | 1917aa6fb2010555680beea5d54367144cec126f /drivers | |
| parent | 49f5bf4e65140344f6ab824571b8325b7bd95d9b (diff) | |
| download | lwn-02a04b98adead5626a395edc21bf6d7f17611938.tar.gz lwn-02a04b98adead5626a395edc21bf6d7f17611938.zip | |
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>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpu/drm/drm_crtc.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index fe738f05309b..2410c4078f3a 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -1868,6 +1868,10 @@ 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; |