linux-kernel - Re: CVE-2024-26628: drm/amdkfd: Fix lock dependency warning

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <Zerheyn-4rB5kySt@tiehlicka>
Date: Fri, 8 Mar 2024 10:59:23 +0100
From: Michal Hocko <mhocko@...e.com>
To: cve@...nel.org, linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Felix Kuehling <felix.kuehling@....com>
Subject: Re: CVE-2024-26628: drm/amdkfd: Fix lock dependency warning

On Wed 06-03-24 06:46:11, Greg KH wrote:
[...]
>  Possible unsafe locking scenario:
> 
>        CPU0                    CPU1
>        ----                    ----
>   lock(&svms->lock);
>                                lock(&mm->mmap_lock);
>                                lock(&svms->lock);
>   lock((work_completion)(&svm_bo->eviction_work));
> 
> I believe this cannot really lead to a deadlock in practice, because
> svm_range_evict_svm_bo_worker only takes the mmap_read_lock if the BO
> refcount is non-0. That means it's impossible that svm_range_bo_release
> is running concurrently. However, there is no good way to annotate this.

OK, so is this even a bug (not to mention a security/weakness)?
-- 
Michal Hocko
SUSE Labs