In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: mt7915: disable rx napi when removing device Unloading the

In the Linux kernel, the following vulnerability has been resolved:

wifi: mt76: mt7915: disable rx napi when removing device

Unloading the mt7915e module with a MT7916 triggers multiples WARN in
__netif_napi_del_locked() and in page_pool_disable_direct_recycling()
because the driver does not disable the napi before destroying it.

This is troublesome since on MT7916 it is required to unload the module
and reinsert it with a different enable_6ghz parameter to change the
frequency. The system generally becomes unstable after reinserting the
module.

Fix it by disabling rx napi inside mt7915e itself, even through napi rx is
enabled in the mt76 generic code. Disabling it in the mt76 generic code
was previously attempted and reverted because napi was disabled too
late and rx handlers could access freed structures. Note that the tx
side is enabled and disabled by the mt76 generic code.

It is disabled in mt7915_stop_hardware() since, unlike
mt7915_unregister_device(), is it also called in the probe path if an
error happens after rx napi is enabled.