drm/xe: Fix bo leak in xe_dma_buf_init_obj() on allocation failure

commit 93a528f67ce5095bcab46a69839eca97f43dd352 upstream.

When drm_gpuvm_resv_object_alloc() fails, the pre-allocated storage bo
is not freed. Add xe_bo_free(storage) before returning the error.

xe_dma_buf_init_obj() calls xe_bo_init_locked(), which frees the bo on
error. Therefore, xe_dma_buf_init_obj() must also free the bo on its own
error paths. Otherwise, since xe_gem_prime_import() cannot distinguish
whether the failure originated from xe_dma_buf_init_obj() or from
xe_bo_init_locked(), it cannot safely decide whether the bo should be
freed.

Add comments documenting the ownership semantics: on success, ownership
of storage is transferred to the returned drm_gem_object; on failure,
storage is freed before returning.

v2: Add comments to explain the free logic.

Fixes: eb289a5f6cc6 ("drm/xe: Convert xe_dma_buf.c for exhaustive eviction")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4.6
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patch.msgid.link/20260408175255.3402838-4-shuicheng.lin@intel.com
Signed-off-by: Shuicheng Lin <shuicheng.lin@intel.com>
(cherry picked from commit 78a6c5f899f22338bbf48b44fb8950409c5a69b9)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/xe/xe_dma_buf.c b/drivers/gpu/drm/xe/xe_dma_buf.c
index 7c74a31d448602cd0c4acc1ea583806c7feb474e..43d1e01c8012647328590a850a610b0277e39b95 100644 (file)
--- a/drivers/gpu/drm/xe/xe_dma_buf.c
+++ b/drivers/gpu/drm/xe/xe_dma_buf.c
@@ -238,6 +238,13 @@ struct dma_buf *xe_gem_prime_export(struct drm_gem_object *obj, int flags)
        return buf;
 }
 
+/*
+ * Takes ownership of @storage: on success it is transferred to the returned
+ * drm_gem_object; on failure it is freed before returning the error.
+ * This matches the contract of xe_bo_init_locked() which frees @storage on
+ * its error paths, so callers need not (and must not) free @storage after
+ * this call.
+ */
 static struct drm_gem_object *
 xe_dma_buf_init_obj(struct drm_device *dev, struct xe_bo *storage,
                    struct dma_buf *dma_buf)
@@ -251,8 +258,10 @@ xe_dma_buf_init_obj(struct drm_device *dev, struct xe_bo *storage,
        int ret = 0;
 
        dummy_obj = drm_gpuvm_resv_object_alloc(&xe->drm);
-       if (!dummy_obj)
+       if (!dummy_obj) {
+               xe_bo_free(storage);
                return ERR_PTR(-ENOMEM);
+       }
 
        dummy_obj->resv = resv;
        xe_validation_guard(&ctx, &xe->val, &exec, (struct xe_val_flags) {}, ret) {
@@ -261,6 +270,7 @@ xe_dma_buf_init_obj(struct drm_device *dev, struct xe_bo *storage,
                if (ret)
                        break;
 
+               /* xe_bo_init_locked() frees storage on error */
                bo = xe_bo_init_locked(xe, storage, NULL, resv, NULL, dma_buf->size,
                                       0, /* Will require 1way or 2way for vm_bind */
                                       ttm_bo_type_sg, XE_BO_FLAG_SYSTEM, &exec);