media: streamzap: fix race between device disconnection and urb callback

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: media: streamzap: fix race between device disconnection and urb callback Syzkaller has reported a general protection fault at function ir_raw_event_store_with_filter(). This crash is caused by a NULL pointer dereference of dev->raw pointer, even though it is checked for NULL in the same function, which means there is a race condition. It occurs due to the incorrect order of actions in the streamzap_disconnect() function: rc_unregister_device() is called before usb_kill_urb(). The dev->raw pointer is freed and set to NULL in rc_unregister_device(), and only after that usb_kill_urb() waits for in-progress requests to finish. If rc_unregister_device() is called while streamzap_callback() handler is not finished, this can lead to accessing freed resources. Thus rc_unregister_device() should be called after usb_kill_urb(). Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

References

• https://git.kernel.org/stable/c/e11652a6514ec805440c1bb3739e6c6236fffcc7
• https://git.kernel.org/stable/c/f1d518c0bad01abe83c2df880274cb6a39f4a457
• https://git.kernel.org/stable/c/30ef7cfee752ca318d5902cb67b60d9797ccd378
• https://git.kernel.org/stable/c/15483afb930fc2f883702dc96f80efbe4055235e
• https://git.kernel.org/stable/c/adf0ddb914c9e5b3e50da4c97959e82de2df75c3
• https://git.kernel.org/stable/c/4db62b60af2ccdea6ac5452fd20e29587ed85f57
• https://git.kernel.org/stable/c/8760da4b9d44c36b93b6e4cf401ec7fe520015bd
• https://git.kernel.org/stable/c/f656cfbc7a293a039d6a0c7100e1c846845148c1