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: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20240314110938.GM1522089@google.com>
Date: Thu, 14 Mar 2024 11:09:38 +0000
From: Lee Jones <lee@...nel.org>
To: Michal Hocko <mhocko@...e.com>
Cc: cve@...nel.org, linux-kernel@...r.kernel.org,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Felix Kuehling <felix.kuehling@....com>
Subject: Re: CVE-2024-26628: drm/amdkfd: Fix lock dependency warning

On Fri, 08 Mar 2024, Michal Hocko wrote:

> 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)?

Looks like the patch fixes a warning which can crash some kernels.  So
the CVE appears to be fixing that, rather than the impossible deadlock.

-- 
Lee Jones [李琼斯]

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ