From ca6c163399a9f1913efdbeab654a185b3cde03c4 Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Mon, 27 Aug 2018 11:20:10 -0400 Subject: [PATCH] media: v4l2-ctrls: use media_request_(un)lock_for_access When getting control values from a completed request, we have to protect the request against being re-inited when it is being accessed by calling media_request_(un)lock_for_access. Signed-off-by: Hans Verkuil Reviewed-by: Tomasz Figa Acked-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab --- drivers/media/v4l2-core/v4l2-ctrls.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c index ccaf3068de6d..cc266a4a6e88 100644 --- a/drivers/media/v4l2-core/v4l2-ctrls.c +++ b/drivers/media/v4l2-core/v4l2-ctrls.c @@ -3289,11 +3289,10 @@ int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct media_device *mdev, struct v4l2_ext_controls *cs) { struct media_request_object *obj = NULL; + struct media_request *req = NULL; int ret; if (cs->which == V4L2_CTRL_WHICH_REQUEST_VAL) { - struct media_request *req; - if (!mdev || cs->request_fd < 0) return -EINVAL; @@ -3306,11 +3305,18 @@ int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct media_device *mdev, return -EACCES; } + ret = media_request_lock_for_access(req); + if (ret) { + media_request_put(req); + return ret; + } + obj = v4l2_ctrls_find_req_obj(hdl, req, false); - /* Reference to the request held through obj */ - media_request_put(req); - if (IS_ERR(obj)) + if (IS_ERR(obj)) { + media_request_unlock_for_access(req); + media_request_put(req); return PTR_ERR(obj); + } hdl = container_of(obj, struct v4l2_ctrl_handler, req_obj); @@ -3318,8 +3324,11 @@ int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct media_device *mdev, ret = v4l2_g_ext_ctrls_common(hdl, cs); - if (obj) + if (obj) { + media_request_unlock_for_access(req); media_request_object_put(obj); + media_request_put(req); + } return ret; } EXPORT_SYMBOL(v4l2_g_ext_ctrls);