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authorXi Wang <xi.wang@gmail.com>2011-11-23 07:12:01 +0100
committerDave Airlie <airlied@redhat.com>2011-11-23 09:59:28 +0100
commita5cd335165e31db9dbab636fd29895d41da55dd2 (patch)
tree4d01d5801047b466c44c40231773e66a9dfb704d /drivers
parentdrivers/gpu/vga/vgaarb.c: add missing kfree (diff)
downloadlinux-a5cd335165e31db9dbab636fd29895d41da55dd2.tar.xz
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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/gpu/drm/drm_crtc.c4
1 files changed, 4 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;