linux-kernel - Re: [PATCH 4/4] x86/mce: Avoid infinite loop for copy from user recovery

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]

Date:   Thu, 8 Apr 2021 15:36:31 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Tony Luck <tony.luck@...el.com>
Cc:     x86@...nel.org, linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        Andy Lutomirski <luto@...nel.org>,
        Aili Yao <yaoaili@...gsoft.com>,
        HORIGUCHI NAOYA( 堀口　直也) 
        <naoya.horiguchi@....com>
Subject: Re: [PATCH 4/4] x86/mce: Avoid infinite loop for copy from user
 recovery

On Thu, Mar 25, 2021 at 05:02:35PM -0700, Tony Luck wrote:
...
> Expected worst case is two machine checks before moving on (e.g. one user
> access with page faults disabled, then a repeat to the same addrsss with
> page faults enabled). Just in case there is some code that loops forever
> enforce a limit of 10.
> 
> Signed-off-by: Tony Luck <tony.luck@...el.com>
> ---
>  arch/x86/kernel/cpu/mce/core.c | 40 ++++++++++++++++++++++++++--------
>  include/linux/sched.h          |  1 +
>  2 files changed, 32 insertions(+), 9 deletions(-)

What I'm still unclear on, does this new version address that
"mysterious" hang or panic which the validation team triggered or you
haven't checked yet?

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette