4.11-stable review patch. If anyone has any objections, please let me know.
------------------
From: Sean Young <sean@xxxxxxxx>
commit 963761a0b2e85663ee4a5630f72930885a06598a upstream.
A rc device can call ir_raw_event_handle() after rc_allocate_device(),
but before rc_register_device() has completed. This is racey because
rcdev->raw is set before rcdev->raw->thread has a valid value.
Reported-by: kbuild test robot <fengguang.wu@xxxxxxxxx>
Signed-off-by: Sean Young <sean@xxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/media/rc/rc-ir-raw.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
--- a/drivers/media/rc/rc-ir-raw.c
+++ b/drivers/media/rc/rc-ir-raw.c
@@ -211,7 +211,7 @@ EXPORT_SYMBOL_GPL(ir_raw_event_set_idle)
*/
void ir_raw_event_handle(struct rc_dev *dev)
{
- if (!dev->raw)
+ if (!dev->raw || !dev->raw->thread)
return;
wake_up_process(dev->raw->thread);
@@ -490,6 +490,7 @@ int ir_raw_event_register(struct rc_dev
{
int rc;
struct ir_raw_handler *handler;
+ struct task_struct *thread;
if (!dev)
return -EINVAL;
@@ -507,13 +508,15 @@ int ir_raw_event_register(struct rc_dev
* because the event is coming from userspace
*/
if (dev->driver_type != RC_DRIVER_IR_RAW_TX) {
- dev->raw->thread = kthread_run(ir_raw_event_thread, dev->raw,
- "rc%u", dev->minor);
+ thread = kthread_run(ir_raw_event_thread, dev->raw, "rc%u",
+ dev->minor);
- if (IS_ERR(dev->raw->thread)) {
- rc = PTR_ERR(dev->raw->thread);
+ if (IS_ERR(thread)) {
+ rc = PTR_ERR(thread);
goto out;
}
+
+ dev->raw->thread = thread;
}
mutex_lock(&ir_raw_handler_lock);