linux-kernel - Re: [PATCH] keys: safe concurrent user->{session,uid}

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Message-ID: <alpine.LRH.2.21.1904110330420.25754@namei.org>
Date:   Thu, 11 Apr 2019 03:31:01 +1000 (AEST)
From:   James Morris <jmorris@...ei.org>
To:     Jann Horn <jannh@...gle.com>
cc:     David Howells <dhowells@...hat.com>,
        "Serge E. Hallyn" <serge@...lyn.com>, linux-kernel@...r.kernel.org,
        keyrings@...r.kernel.org, linux-security-module@...r.kernel.org
Subject: Re: [PATCH] keys: safe concurrent user->{session,uid}_keyring
 access

On Wed, 27 Mar 2019, Jann Horn wrote:

> The current code can perform concurrent updates and reads on
> user->session_keyring and user->uid_keyring. Add a comment to
> struct user_struct to document the nontrivial locking semantics, and use
> READ_ONCE() for unlocked readers and smp_store_release() for writers to
> prevent memory ordering issues.
> 
> Fixes: 69664cf16af4 ("keys: don't generate user and user session keyrings unless they're accessed")
> Signed-off-by: Jann Horn <jannh@...gle.com>

Applied to
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security.git next-general


-- 
James Morris
<jmorris@...ei.org>