From: Niklas Söderlund Date: Sat, 4 Nov 2017 02:25:56 +0000 (-0400) Subject: media: v4l: async: fix unregister for implicitly registered sub-device notifiers X-Git-Tag: Ubuntu-5.13.0-19.19~12170^2~14 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=1453ad81a2be1bef9243671480694d483ab0dad0;p=mirror_ubuntu-jammy-kernel.git media: v4l: async: fix unregister for implicitly registered sub-device notifiers The commit aef69d54755d45ed ("media: v4l: fwnode: Add a convenience function for registering sensors") adds the function v4l2_async_notifier_parse_fwnode_sensor_common() to parse and register a subdevice and a subdev-notifier by parsing firmware information. This new subdev-notifier is stored in the new field 'subdev_notifier' in struct v4l2_subdev. In v4l2_async_unregister_subdev() this field is used to unregister and cleanup the subdev-notifier. A check for if the subdev-notifier is initialized or not was forgotten leading to a NULL pointer dereference in v4l2_async_notifier_cleanup() if a subdevice do not use the optional convince function to initialize the field. Fix this by checking in v4l2_async_notifier_cleanup() that it is provided whit a notifier making it safe to call with a NULL parameter. Fixes: aef69d54755d45ed ("media: v4l: fwnode: Add a convenience function for registering sensors") Signed-off-by: Niklas Söderlund Signed-off-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab --- diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c index 7020b2e6d158..a7c3464976f2 100644 --- a/drivers/media/v4l2-core/v4l2-async.c +++ b/drivers/media/v4l2-core/v4l2-async.c @@ -502,7 +502,7 @@ void v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier) { unsigned int i; - if (!notifier->max_subdevs) + if (!notifier || !notifier->max_subdevs) return; for (i = 0; i < notifier->num_subdevs; i++) {