Skip to content

Commit a5cd335

Browse files
xiwairlied
authored andcommitted
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>
1 parent c916874 commit a5cd335

File tree

2 files changed

+6
-0
lines changed

2 files changed

+6
-0
lines changed

Diff for: drivers/gpu/drm/drm_crtc.c

+4
Original file line numberDiff line numberDiff line change
@@ -1873,6 +1873,10 @@ int drm_mode_dirtyfb_ioctl(struct drm_device *dev,
18731873
}
18741874

18751875
if (num_clips && clips_ptr) {
1876+
if (num_clips < 0 || num_clips > DRM_MODE_FB_DIRTY_MAX_CLIPS) {
1877+
ret = -EINVAL;
1878+
goto out_err1;
1879+
}
18761880
clips = kzalloc(num_clips * sizeof(*clips), GFP_KERNEL);
18771881
if (!clips) {
18781882
ret = -ENOMEM;

Diff for: include/drm/drm_mode.h

+2
Original file line numberDiff line numberDiff line change
@@ -235,6 +235,8 @@ struct drm_mode_fb_cmd {
235235
#define DRM_MODE_FB_DIRTY_ANNOTATE_FILL 0x02
236236
#define DRM_MODE_FB_DIRTY_FLAGS 0x03
237237

238+
#define DRM_MODE_FB_DIRTY_MAX_CLIPS 256
239+
238240
/*
239241
* Mark a region of a framebuffer as dirty.
240242
*

0 commit comments

Comments
 (0)