Commit 7fc4fdb9 authored by Sakari Ailus's avatar Sakari Ailus Committed by Mauro Carvalho Chehab

media: v4l: async: Correctly serialise async sub-device unregistration

The check whether an async sub-device is bound to a notifier was performed
without list_lock held, making it possible for another process to
unbind the async sub-device before the sub-device unregistration function
proceeds to take the lock.

Fix this by first acquiring the lock and then proceeding with the check.
Signed-off-by: default avatarSakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: default avatarSebastian Reichel <sebastian.reichel@collabora.co.uk>
Acked-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Acked-by: default avatarNiklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent fb45f436
...@@ -298,20 +298,16 @@ EXPORT_SYMBOL(v4l2_async_register_subdev); ...@@ -298,20 +298,16 @@ EXPORT_SYMBOL(v4l2_async_register_subdev);
void v4l2_async_unregister_subdev(struct v4l2_subdev *sd) void v4l2_async_unregister_subdev(struct v4l2_subdev *sd)
{ {
struct v4l2_async_notifier *notifier = sd->notifier;
if (!sd->asd) {
if (!list_empty(&sd->async_list))
v4l2_async_cleanup(sd);
return;
}
mutex_lock(&list_lock); mutex_lock(&list_lock);
list_add(&sd->asd->list, &notifier->waiting); if (sd->asd) {
struct v4l2_async_notifier *notifier = sd->notifier;
if (notifier->unbind) list_add(&sd->asd->list, &notifier->waiting);
notifier->unbind(notifier, sd, sd->asd);
if (notifier->unbind)
notifier->unbind(notifier, sd, sd->asd);
}
v4l2_async_cleanup(sd); v4l2_async_cleanup(sd);
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment