From 7b4c52fd559767f7c7405874d117ec65541ed213 Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Fri, 22 Aug 2025 21:46:18 -0400 Subject: [PATCH] media: v4l2-ctrls: always copy the controls on completion [ Upstream commit c3bf5129f33923c92bf3bddaf4359b7b25ecb4ba ] When v4l2_ctrl_request_complete() is called and there is no control handler object found in the request, then create such an object so that all controls at completion state can be stored and are available to userspace. Otherwise any attempt by userspace to read the completed request data will fail. If allocating the control handler object failed, then indicate that by returning ENOMEM when attempting to get the controls from the completed request instead of returning ENOENT. Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Stable-dep-of: 5a0400aca5fa ("media: v4l2-ctrls: Don't reset handler's error in v4l2_ctrl_handler_free()") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/media/v4l2-core/v4l2-ctrls.c | 36 ++++++++++++++++++++++++---- 1 file changed, 32 insertions(+), 4 deletions(-) diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c index 41f8410d08d65..a84136f76d8ec 100644 --- a/drivers/media/v4l2-core/v4l2-ctrls.c +++ b/drivers/media/v4l2-core/v4l2-ctrls.c @@ -3767,8 +3767,19 @@ v4l2_ctrls_find_req_obj(struct v4l2_ctrl_handler *hdl, obj = media_request_object_find(req, &req_ops, hdl); if (obj) return obj; + /* + * If there are no controls in this completed request, + * then that can only happen if: + * + * 1) no controls were present in the queued request, and + * 2) v4l2_ctrl_request_complete() could not allocate a + * control handler object to store the completed state in. + * + * So return ENOMEM to indicate that there was an out-of-memory + * error. + */ if (!set) - return ERR_PTR(-ENOENT); + return ERR_PTR(-ENOMEM); new_hdl = kzalloc(sizeof(*new_hdl), GFP_KERNEL); if (!new_hdl) @@ -3779,8 +3790,8 @@ v4l2_ctrls_find_req_obj(struct v4l2_ctrl_handler *hdl, if (!ret) ret = v4l2_ctrl_request_bind(req, new_hdl, hdl); if (ret) { + v4l2_ctrl_handler_free(new_hdl); kfree(new_hdl); - return ERR_PTR(ret); } @@ -4369,8 +4380,25 @@ void v4l2_ctrl_request_complete(struct media_request *req, * wants to leave the controls unchanged. */ obj = media_request_object_find(req, &req_ops, main_hdl); - if (!obj) - return; + if (!obj) { + int ret; + + /* Create a new request so the driver can return controls */ + hdl = kzalloc(sizeof(*hdl), GFP_KERNEL); + if (!hdl) + return; + + ret = v4l2_ctrl_handler_init(hdl, (main_hdl->nr_of_buckets - 1) * 8); + if (!ret) + ret = v4l2_ctrl_request_bind(req, hdl, main_hdl); + if (ret) { + v4l2_ctrl_handler_free(hdl); + kfree(hdl); + return; + } + hdl->request_is_queued = true; + obj = media_request_object_find(req, &req_ops, main_hdl); + } hdl = container_of(obj, struct v4l2_ctrl_handler, req_obj); list_for_each_entry(ref, &hdl->ctrl_refs, node) { -- 2.47.3