From: Michel Dänzer michel.daenzer@amd.com
Fixes a use-after-free due to a race condition in ttm_bo_cleanup_refs_and_unlock, which allows one task to reserve a BO and destroy its ttm_resv while another task is waiting for it to signal in reservation_object_wait_timeout_rcu.
commit e1fc12c5d9ad06a2a74e97a91f1b0c5f4c723b50 upstream
v2: * Always initialize bo->ttm_resv in ttm_bo_init_reserved (Christian König)
Fixes: 0d2bd2ae045d "drm/ttm: fix memory leak while individualizing BOs" Reviewed-by: Chunming Zhou david1.zhou@amd.com # v1 Reviewed-by: Christian König christian.koenig@amd.com Signed-off-by: Michel Dänzer michel.daenzer@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Lyude Paul lyude@redhat.com --- drivers/gpu/drm/ttm/ttm_bo.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c index bee77d31895b..c088703777e2 100644 --- a/drivers/gpu/drm/ttm/ttm_bo.c +++ b/drivers/gpu/drm/ttm/ttm_bo.c @@ -150,8 +150,7 @@ static void ttm_bo_release_list(struct kref *list_kref) ttm_tt_destroy(bo->ttm); atomic_dec(&bo->glob->bo_count); dma_fence_put(bo->moving); - if (bo->resv == &bo->ttm_resv) - reservation_object_fini(&bo->ttm_resv); + reservation_object_fini(&bo->ttm_resv); mutex_destroy(&bo->wu_mutex); if (bo->destroy) bo->destroy(bo); @@ -402,14 +401,11 @@ static int ttm_bo_individualize_resv(struct ttm_buffer_object *bo) if (bo->resv == &bo->ttm_resv) return 0;
- reservation_object_init(&bo->ttm_resv); BUG_ON(!reservation_object_trylock(&bo->ttm_resv));
r = reservation_object_copy_fences(&bo->ttm_resv, bo->resv); - if (r) { + if (r) reservation_object_unlock(&bo->ttm_resv); - reservation_object_fini(&bo->ttm_resv); - }
return r; } @@ -459,6 +455,7 @@ static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo) spin_unlock(&glob->lru_lock); if (bo->resv != &bo->ttm_resv) reservation_object_unlock(&bo->ttm_resv); + ttm_bo_cleanup_memtype_use(bo); return; } @@ -1205,8 +1202,8 @@ int ttm_bo_init_reserved(struct ttm_bo_device *bdev, lockdep_assert_held(&bo->resv->lock.base); } else { bo->resv = &bo->ttm_resv; - reservation_object_init(&bo->ttm_resv); } + reservation_object_init(&bo->ttm_resv); atomic_inc(&bo->glob->bo_count); drm_vma_node_reset(&bo->vma_node); bo->priority = 0;