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authorSean Young <sean@mess.org>2017-05-24 06:24:51 -0300
committerMauro Carvalho Chehab <mchehab@s-opensource.com>2017-06-04 15:25:38 -0300
commit963761a0b2e85663ee4a5630f72930885a06598a (patch)
tree013955d01bc1907b0513037c35baa57f0b6d3ee8
parent20249f84238e006ef7b726d3211a70de7454d045 (diff)
[media] rc-core: race condition during ir_raw_event_register()media/v4.12-2
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. Cc: stable@kernel.org Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Sean Young <sean@mess.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
-rw-r--r--drivers/media/rc/rc-ir-raw.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/drivers/media/rc/rc-ir-raw.c b/drivers/media/rc/rc-ir-raw.c
index 90f66dc7c0d7..a2fc1a1d58b0 100644
--- 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 *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 *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);

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