This is a note to let you know that I've just added the patch titled drm/ttm, drm/vmwgfx: Relax permission checking when opening surfaces to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-ttm-drm-vmwgfx-relax-permission-checking-when-opening-surfaces.patch and it can be found in the queue-3.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From fe25deb7737ce6c0879ccf79c99fa1221d428bf2 Mon Sep 17 00:00:00 2001 From: Thomas Hellstrom <thellstrom@xxxxxxxxxx> Date: Mon, 27 Mar 2017 11:21:25 +0200 Subject: drm/ttm, drm/vmwgfx: Relax permission checking when opening surfaces From: Thomas Hellstrom <thellstrom@xxxxxxxxxx> commit fe25deb7737ce6c0879ccf79c99fa1221d428bf2 upstream. Previously, when a surface was opened using a legacy (non prime) handle, it was verified to have been created by a client in the same master realm. Relax this so that opening is also allowed recursively if the client already has the surface open. This works around a regression in svga mesa where opening of a shared surface is used recursively to obtain surface information. Signed-off-by: Thomas Hellstrom <thellstrom@xxxxxxxxxx> Reviewed-by: Sinclair Yeh <syeh@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/ttm/ttm_object.c | 10 +++++++--- drivers/gpu/drm/vmwgfx/vmwgfx_fence.c | 6 ++---- drivers/gpu/drm/vmwgfx/vmwgfx_resource.c | 4 ++-- drivers/gpu/drm/vmwgfx/vmwgfx_surface.c | 22 +++++++++------------- include/drm/ttm/ttm_object.h | 5 ++++- 5 files changed, 24 insertions(+), 23 deletions(-) --- a/drivers/gpu/drm/ttm/ttm_object.c +++ b/drivers/gpu/drm/ttm/ttm_object.c @@ -179,7 +179,7 @@ int ttm_base_object_init(struct ttm_obje if (unlikely(ret != 0)) goto out_err0; - ret = ttm_ref_object_add(tfile, base, TTM_REF_USAGE, NULL); + ret = ttm_ref_object_add(tfile, base, TTM_REF_USAGE, NULL, false); if (unlikely(ret != 0)) goto out_err1; @@ -318,7 +318,8 @@ EXPORT_SYMBOL(ttm_ref_object_exists); int ttm_ref_object_add(struct ttm_object_file *tfile, struct ttm_base_object *base, - enum ttm_ref_type ref_type, bool *existed) + enum ttm_ref_type ref_type, bool *existed, + bool require_existed) { struct drm_open_hash *ht = &tfile->ref_hash[ref_type]; struct ttm_ref_object *ref; @@ -345,6 +346,9 @@ int ttm_ref_object_add(struct ttm_object } rcu_read_unlock(); + if (require_existed) + return -EPERM; + ret = ttm_mem_global_alloc(mem_glob, sizeof(*ref), false, false); if (unlikely(ret != 0)) @@ -635,7 +639,7 @@ int ttm_prime_fd_to_handle(struct ttm_ob prime = (struct ttm_prime_object *) dma_buf->priv; base = &prime->base; *handle = base->hash.key; - ret = ttm_ref_object_add(tfile, base, TTM_REF_USAGE, NULL); + ret = ttm_ref_object_add(tfile, base, TTM_REF_USAGE, NULL, false); dma_buf_put(dma_buf); --- a/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c @@ -1144,10 +1144,8 @@ int vmw_fence_event_ioctl(struct drm_dev (void) vmw_fence_obj_reference(fence); if (user_fence_rep != NULL) { - bool existed; - - ret = ttm_ref_object_add(tfile, base, - TTM_REF_USAGE, &existed); + ret = ttm_ref_object_add(vmw_fp->tfile, base, + TTM_REF_USAGE, NULL, false); if (unlikely(ret != 0)) { DRM_ERROR("Failed to reference a fence " "object.\n"); --- a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c @@ -588,7 +588,7 @@ static int vmw_user_dmabuf_synccpu_grab( return ret; ret = ttm_ref_object_add(tfile, &user_bo->prime.base, - TTM_REF_SYNCCPU_WRITE, &existed); + TTM_REF_SYNCCPU_WRITE, &existed, false); if (ret != 0 || existed) ttm_bo_synccpu_write_release(&user_bo->dma.base); @@ -764,7 +764,7 @@ int vmw_user_dmabuf_reference(struct ttm *handle = user_bo->prime.base.hash.key; return ttm_ref_object_add(tfile, &user_bo->prime.base, - TTM_REF_USAGE, NULL); + TTM_REF_USAGE, NULL, false); } /* --- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c @@ -895,17 +895,16 @@ vmw_surface_handle_reference(struct vmw_ uint32_t handle; struct ttm_base_object *base; int ret; + bool require_exist = false; if (handle_type == DRM_VMW_HANDLE_PRIME) { ret = ttm_prime_fd_to_handle(tfile, u_handle, &handle); if (unlikely(ret != 0)) return ret; } else { - if (unlikely(drm_is_render_client(file_priv))) { - DRM_ERROR("Render client refused legacy " - "surface reference.\n"); - return -EACCES; - } + if (unlikely(drm_is_render_client(file_priv))) + require_exist = true; + handle = u_handle; } @@ -927,17 +926,14 @@ vmw_surface_handle_reference(struct vmw_ /* * Make sure the surface creator has the same - * authenticating master. + * authenticating master, or is already registered with us. */ if (drm_is_primary_client(file_priv) && - user_srf->master != file_priv->master) { - DRM_ERROR("Trying to reference surface outside of" - " master domain.\n"); - ret = -EACCES; - goto out_bad_resource; - } + user_srf->master != file_priv->master) + require_exist = true; - ret = ttm_ref_object_add(tfile, base, TTM_REF_USAGE, NULL); + ret = ttm_ref_object_add(tfile, base, TTM_REF_USAGE, NULL, + require_exist); if (unlikely(ret != 0)) { DRM_ERROR("Could not add a reference to a surface.\n"); goto out_bad_resource; --- a/include/drm/ttm/ttm_object.h +++ b/include/drm/ttm/ttm_object.h @@ -229,6 +229,8 @@ extern void ttm_base_object_unref(struct * @ref_type: The type of reference. * @existed: Upon completion, indicates that an identical reference object * already existed, and the refcount was upped on that object instead. + * @require_existed: Fail with -EPERM if an identical ref object didn't + * already exist. * * Checks that the base object is shareable and adds a ref object to it. * @@ -243,7 +245,8 @@ extern void ttm_base_object_unref(struct */ extern int ttm_ref_object_add(struct ttm_object_file *tfile, struct ttm_base_object *base, - enum ttm_ref_type ref_type, bool *existed); + enum ttm_ref_type ref_type, bool *existed, + bool require_existed); extern bool ttm_ref_object_exists(struct ttm_object_file *tfile, struct ttm_base_object *base); Patches currently in stable-queue which might be from thellstrom@xxxxxxxxxx are queue-3.18/drm-vmwgfx-remove-getparam-error-message.patch queue-3.18/drm-vmwgfx-type-check-lookups-of-fence-objects.patch queue-3.18/drm-vmwgfx-fix-integer-overflow-in-vmw_surface_define_ioctl.patch queue-3.18/drm-ttm-drm-vmwgfx-relax-permission-checking-when-opening-surfaces.patch