drm/radeon: make VCE handle check more strict

Invalid handles can crash the hw.

Signed-off-by: Christian König <christian.koenig@amd.com>
CC: stable@vger.kernel.org
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 48 insertions, 17 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_vce.c b/drivers/gpu/drm/radeon/radeon_vce.c
index 24f849f888bb..0de5711ac508 100644
--- a/drivers/gpu/drm/radeon/radeon_vce.c
+++ b/drivers/gpu/drm/radeon/radeon_vce.c
@@ -493,18 +493,27 @@ int radeon_vce_cs_reloc(struct radeon_cs_parser *p, int lo, int hi,
  *
  * @p: parser context
  * @handle: handle to validate
+ * @allocated: allocated a new handle?
  *
  * Validates the handle and return the found session index or -EINVAL
  * we we don't have another free session index.
  */
-int radeon_vce_validate_handle(struct radeon_cs_parser *p, uint32_t handle)
+static int radeon_vce_validate_handle(struct radeon_cs_parser *p,
+                                      uint32_t handle, bool *allocated)
 {
         unsigned i;
 
+        *allocated = false;
+
         /* validate the handle */
         for (i = 0; i < RADEON_MAX_VCE_HANDLES; ++i) {
-                if (atomic_read(&p->rdev->vce.handles[i]) == handle)
+                if (atomic_read(&p->rdev->vce.handles[i]) == handle) {
+                        if (p->rdev->vce.filp[i] != p->filp) {
+                                DRM_ERROR("VCE handle collision detected!\n");
+                                return -EINVAL;
+                        }
                         return i;
+                }
         }
 
         /* handle not found try to alloc a new one */
@@ -512,6 +521,7 @@ int radeon_vce_validate_handle(struct radeon_cs_parser *p, uint32_t handle)
                 if (!atomic_cmpxchg(&p->rdev->vce.handles[i], 0, handle)) {
                         p->rdev->vce.filp[i] = p->filp;
                         p->rdev->vce.img_size[i] = 0;
+                        *allocated = true;
                         return i;
                 }
         }
@@ -529,10 +539,10 @@ int radeon_vce_validate_handle(struct radeon_cs_parser *p, uint32_t handle)
 int radeon_vce_cs_parse(struct radeon_cs_parser *p)
 {
         int session_idx = -1;
-        bool destroyed = false;
+        bool destroyed = false, created = false, allocated = false;
         uint32_t tmp, handle = 0;
         uint32_t *size = &tmp;
-        int i, r;
+        int i, r = 0;
 
         while (p->idx < p->chunk_ib->length_dw) {
                 uint32_t len = radeon_get_ib_value(p, p->idx);
@@ -540,18 +550,21 @@ int radeon_vce_cs_parse(struct radeon_cs_parser *p)
 
                 if ((len < 8) || (len & 3)) {
                         DRM_ERROR("invalid VCE command length (%d)!\n", len);
-                        return -EINVAL;
+                        r = -EINVAL;
+                        goto out;
                 }
 
                 if (destroyed) {
                         DRM_ERROR("No other command allowed after destroy!\n");
-                        return -EINVAL;
+                        r = -EINVAL;
+                        goto out;
                 }
 
                 switch (cmd) {
                 case 0x00000001: // session
                         handle = radeon_get_ib_value(p, p->idx + 2);
-                        session_idx = radeon_vce_validate_handle(p, handle);
+                        session_idx = radeon_vce_validate_handle(p, handle,
+                                                                 &allocated);
                         if (session_idx < 0)
                                 return session_idx;
                         size = &p->rdev->vce.img_size[session_idx];
@@ -561,6 +574,13 @@ int radeon_vce_cs_parse(struct radeon_cs_parser *p)
                         break;
 
                 case 0x01000001: // create
+                        created = true;
+                        if (!allocated) {
+                                DRM_ERROR("Handle already in use!\n");
+                                r = -EINVAL;
+                                goto out;
+                        }
+
                         *size = radeon_get_ib_value(p, p->idx + 8) *
                                 radeon_get_ib_value(p, p->idx + 10) *
                                 8 * 3 / 2;
@@ -578,12 +598,12 @@ int radeon_vce_cs_parse(struct radeon_cs_parser *p)
                         r = radeon_vce_cs_reloc(p, p->idx + 10, p->idx + 9,
                                                 *size);
                         if (r)
-                                return r;
+                                goto out;
 
                         r = radeon_vce_cs_reloc(p, p->idx + 12, p->idx + 11,
                                                 *size / 3);
                         if (r)
-                                return r;
+                                goto out;
                         break;
 
                 case 0x02000001: // destroy
@@ -594,7 +614,7 @@ int radeon_vce_cs_parse(struct radeon_cs_parser *p)
                         r = radeon_vce_cs_reloc(p, p->idx + 3, p->idx + 2,
                                                 *size * 2);
                         if (r)
-                                return r;
+                                goto out;
                         break;
 
                 case 0x05000004: // video bitstream buffer
@@ -602,36 +622,47 @@ int radeon_vce_cs_parse(struct radeon_cs_parser *p)
                         r = radeon_vce_cs_reloc(p, p->idx + 3, p->idx + 2,
                                                 tmp);
                         if (r)
-                                return r;
+                                goto out;
                         break;
 
                 case 0x05000005: // feedback buffer
                         r = radeon_vce_cs_reloc(p, p->idx + 3, p->idx + 2,
                                                 4096);
                         if (r)
-                                return r;
+                                goto out;
                         break;
 
                 default:
                         DRM_ERROR("invalid VCE command (0x%x)!\n", cmd);
-                        return -EINVAL;
+                        r = -EINVAL;
+                        goto out;
                 }
 
                 if (session_idx == -1) {
                         DRM_ERROR("no session command at start of IB\n");
-                        return -EINVAL;
+                        r = -EINVAL;
+                        goto out;
                 }
 
                 p->idx += len / 4;
         }
 
-        if (destroyed) {
-                /* IB contains a destroy msg, free the handle */
+        if (allocated && !created) {
+                DRM_ERROR("New session without create command!\n");
+                r = -ENOENT;
+        }
+
+out:
+        if ((!r && destroyed) || (r && allocated)) {
+                /*
+                 * IB contains a destroy msg or we have allocated an
+                 * handle and got an error, anyway free the handle
+                 */
                 for (i = 0; i < RADEON_MAX_VCE_HANDLES; ++i)
                         atomic_cmpxchg(&p->rdev->vce.handles[i], handle, 0);
         }
 
-        return 0;
+        return r;
 }
 
 /**