[PATCH 3.12 132/142] drm/radeon: make UVD handle checking more strict

Jiri Slaby
2015-05-16T08:40:00Z

From: Christian König <christian.koenig@amd.com>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

commit a1b403da70e038ca6c6c6fe434d1d873546873a3 upstream.

Invalid messages can crash the hw otherwise.

Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/gpu/drm/radeon/radeon_uvd.c | 72 ++++++++++++++++++++++---------------
1 file changed, 43 insertions(+), 29 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_uvd.c b/drivers/gpu/drm/radeon/radeon_uvd.c
index a656b1a7e10a..a8cc5ff8e48f 100644
--- a/drivers/gpu/drm/radeon/radeon_uvd.c
+++ b/drivers/gpu/drm/radeon/radeon_uvd.c
@@ -387,50 +387,64 @@ static int radeon_uvd_cs_msg(struct radeon_cs_parser *p, struct radeon_bo *bo,
return -EINVAL;
}

- if (msg_type == 1) {
+ switch (msg_type) {
+ case 0:
+ /* it's a create msg, calc image size (width * height) */
+ img_size = msg[7] * msg[8];
+ radeon_bo_kunmap(bo);
+
+ /* try to alloc a new handle */
+ for (i = 0; i < RADEON_MAX_UVD_HANDLES; ++i) {
+ if (atomic_read(&p->rdev->uvd.handles[i]) == handle) {
+ DRM_ERROR("Handle 0x%x already in use!\n", handle);
+ return -EINVAL;
+ }
+
+ if (!atomic_cmpxchg(&p->rdev->uvd.handles[i], 0, handle)) {
+ p->rdev->uvd.filp[i] = p->filp;
+ p->rdev->uvd.img_size[i] = img_size;
+ return 0;
+ }
+ }
+
+ DRM_ERROR("No more free UVD handles!\n");
+ return -EINVAL;
+
+ case 1:
/* it's a decode msg, calc buffer sizes */
r = radeon_uvd_cs_msg_decode(msg, buf_sizes);
- /* calc image size (width * height) */
- img_size = msg[6] * msg[7];
radeon_bo_kunmap(bo);
if (r)
return r;

- } else if (msg_type == 2) {
+ /* validate the handle */
+ for (i = 0; i < RADEON_MAX_UVD_HANDLES; ++i) {
+ if (atomic_read(&p->rdev->uvd.handles[i]) == handle) {
+ if (p->rdev->uvd.filp[i] != p->filp) {
+ DRM_ERROR("UVD handle collision detected!\n");
+ return -EINVAL;
+ }
+ return 0;
+ }
+ }
+
+ DRM_ERROR("Invalid UVD handle 0x%x!\n", handle);
+ return -ENOENT;
+
+ case 2:
/* it's a destroy msg, free the handle */
for (i = 0; i < RADEON_MAX_UVD_HANDLES; ++i)
atomic_cmpxchg(&p->rdev->uvd.handles[i], handle, 0);
radeon_bo_kunmap(bo);
return 0;
- } else {
- /* it's a create msg, calc image size (width * height) */
- img_size = msg[7] * msg[8];
- radeon_bo_kunmap(bo);

- if (msg_type != 0) {
- DRM_ERROR("Illegal UVD message type (%d)!\n", msg_type);
- return -EINVAL;
- }
-
- /* it's a create msg, no special handling needed */
- }
-
- /* create or decode, validate the handle */
- for (i = 0; i < RADEON_MAX_UVD_HANDLES; ++i) {
- if (atomic_read(&p->rdev->uvd.handles[i]) == handle)
- return 0;
- }
+ default:

- /* handle not found try to alloc a new one */
- for (i = 0; i < RADEON_MAX_UVD_HANDLES; ++i) {
- if (!atomic_cmpxchg(&p->rdev->uvd.handles[i], 0, handle)) {
- p->rdev->uvd.filp[i] = p->filp;
- p->rdev->uvd.img_size[i] = img_size;
- return 0;
- }
+ DRM_ERROR("Illegal UVD message type (%d)!\n", msg_type);
+ return -EINVAL;
}

- DRM_ERROR("No more free UVD handles!\n");
+ BUG();
return -EINVAL;
}

--
2.3.7