Re: [PATCH v8 0/2] KEYS: Read keys to internal buffer & then copy to userspace

David Miller
2020-03-26T02:30:59Z

From: Waiman Long <longman@redhat.com>
Date: Sat, 21 Mar 2020 21:11:23 -0400

> The current security key read methods are called with the key semaphore
> held. The methods then copy out the key data to userspace which is
> subjected to page fault and may acquire the mmap semaphore. That can
> result in circular lock dependency and hence a chance to get into
> deadlock.
>
> To avoid such a deadlock, an internal buffer is now allocated for getting
> out the necessary data first. After releasing the key semaphore, the
> key data are then copied out to userspace sidestepping the circular
> lock dependency.
>
> The keyutils test suite was run and the test passed with these patchset
> applied without any falure.

Who will integrate these changes?