[PATCH] drm/radeon: check buffer relocation offset

[Leo Liu]

Signed-off-by: Leo Liu <leo.liu at amd.com>
Cc:stable at vger.kernel.org
---
 drivers/gpu/drm/radeon/radeon_uvd.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/radeon/radeon_uvd.c 
b/drivers/gpu/drm/radeon/radeon_uvd.c
index 5748bda..0f96c47 100644
--- a/drivers/gpu/drm/radeon/radeon_uvd.c
+++ b/drivers/gpu/drm/radeon/radeon_uvd.c
@@ -465,6 +465,10 @@ static int radeon_uvd_cs_reloc(struct radeon_cs_parser *p,
        cmd = radeon_get_ib_value(p, p->idx) >> 1;

        if (cmd < 0x4) {
+               if (end <= start) {
+                       DRM_ERROR("invalid reloc offset %X!\n", offset);
+                       return -EINVAL;
+               }
                if ((end - start) < buf_sizes[cmd]) {
                        DRM_ERROR("buffer (%d) to small (%d / %d)!\n", cmd,
                                  (unsigned)(end - start), buf_sizes[cmd]);
-- 
1.9.1