5.10-stable review patch. If anyone has any objections, please let me know.
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From: Hans Verkuil hverkuil-cisco@xs4all.nl
[ 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 hverkuil-cisco@xs4all.nl Signed-off-by: Mauro Carvalho Chehab mchehab+huawei@kernel.org Stable-dep-of: 5a0400aca5fa ("media: v4l2-ctrls: Don't reset handler's error in v4l2_ctrl_handler_free()") Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/media/v4l2-core/v4l2-ctrls.c | 36 +++++++++++++++++++++++++++++++---- 1 file changed, 32 insertions(+), 4 deletions(-)
--- 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 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 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 m * 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) {