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Subject: Re: [PATCH 0/8] ucounts: RLIMIT_NPROC fixes
To:     "Eric W. Biederman" <ebiederm@xmission.com>,
        linux-kernel@vger.kernel.org
Cc:     Alexey Gladkov <legion@kernel.org>,
        Kees Cook <keescook@chromium.org>,
        Shuah Khan <shuah@kernel.org>,
        Christian Brauner <brauner@kernel.org>,
        Solar Designer <solar@openwall.com>,
        Ran Xiaokai <ran.xiaokai@zte.com.cn>,
        Linux Containers <containers@lists.linux-foundation.org>,
        =?UTF-8?Q?Michal_Koutn=c3=bd?= <mkoutny@suse.com>,
        Shuah Khan <skhan@linuxfoundation.org>
References: <20220207121800.5079-1-mkoutny@suse.com>
 <87o83e2mbu.fsf@email.froward.int.ebiederm.org>
From:   Shuah Khan <skhan@linuxfoundation.org>
Message-ID: <f0d686aa-3fad-afac-d377-f5d63111704a@linuxfoundation.org>
Date:   Fri, 11 Feb 2022 11:22:13 -0700
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On 2/10/22 7:01 PM, Eric W. Biederman wrote:
> 
> Michal Koutný recently found some bugs in the enforcement of
> RLIMIT_NPROC in the recent ucount rlimit implementation.
> 
> I saw some additional bugs and some cleaner ways to fix the problem so
> instead of starting with his fixes these are my own.
> 
> I am aiming to send the first 5 of these to Linus once they have been
> reviewed.  Two more are fixes in principle but I don't think do anything
> in practice.  The last one is just a cleanup to prevent future
> divergence of RLIMIT_NPROC logic.
> 
> Eric W. Biederman (8):
>        ucounts: Fix RLIMIT_NPROC regression
>        ucounts: Fix set_cred_ucounts
>        ucounts: Fix and simplify RLIMIT_NPROC handling during setuid()+execve
>        ucounts: Only except the root user in init_user_ns from RLIMIT_NPROC

Should this be "Only exempt"?
  
>        ucounts: Handle wrapping in is_ucounts_overlimit
>        ucounts: Handle inc_rlimit_ucounts wrapping in fork
>        rlimit: For RLIMIT_NPROC test the child not the parent for capabilites
>        ucounts: Use the same code to enforce RLIMIT_NPROC in fork and exec
> 
>   fs/exec.c                    | 12 +++++-------
>   include/linux/sched.h        |  2 +-
>   include/linux/sched/signal.h |  2 ++
>   kernel/cred.c                | 24 +++++++++++-------------
>   kernel/fork.c                | 32 ++++++++++++++++++++++++--------
>   kernel/sys.c                 | 14 --------------
>   kernel/ucount.c              |  3 ++-
>   kernel/user_namespace.c      |  2 ++
>   8 files changed, 47 insertions(+), 44 deletions(-)
> 
> Eric
> 

Do we need updates to selftests - Michal's patch series included changes to
selftests/exec

thanks,
-- Shuah