Hi,
When a subdevice is registered with
v4l2_async_register_subdev_sensor_common and the main driver is
unloaded and reloaded, it does not register a node for the subdevice
since the devonde is not set to null.
in v4l2_device_register_subdev_nodes the sd is skipped if sd->devnode.
This patch solves this issue as well.
Dafna
On 19.02.20 16:25, Dafna Hirschfeld wrote:
sd->devnode is released after calling
v4l2_subdev_release. Therefore it should be set
to NULL so that the subdev won't hold a pointer
to a released object. This fixes a reference
after free bug in function
v4l2_device_unregister_subdev
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 0e43734d4c46e ("media: v4l2-subdev: add release() internal op")
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@xxxxxxxxxxxxx>
Reviewed-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
---
changes since v2:
- since this is a regresion fix, I added Fixes and Cc to stable tags,
- change the commit title and log to be more clear.
changes since v3:
move the sd->devnode = NULL; line below the call to the release cb
so that it can still use it.
drivers/media/v4l2-core/v4l2-device.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/media/v4l2-core/v4l2-device.c b/drivers/media/v4l2-core/v4l2-device.c
index 63d6b147b21e..41da73ce2e98 100644
--- a/drivers/media/v4l2-core/v4l2-device.c
+++ b/drivers/media/v4l2-core/v4l2-device.c
@@ -179,6 +179,7 @@ static void v4l2_subdev_release(struct v4l2_subdev *sd)
if (sd->internal_ops && sd->internal_ops->release)
sd->internal_ops->release(sd);
+ sd->devnode = NULL;
module_put(owner);
}
