linux-kernel - Re: [LTP] [PATCH] syscall/ptrace08: Simplify the test.

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] [day] [month] [year] [list]

Message-ID: <20200904133001.GA9091@yuki.lan>
Date:   Fri, 4 Sep 2020 15:30:01 +0200
From:   Cyril Hrubis <chrubis@...e.cz>
To:     Thadeu Lima de Souza Cascardo <cascardo@...onical.com>
Cc:     ltp@...ts.linux.it,
        Alexandre Chartre <alexandre.chartre@...cle.com>,
        Peter Zijlstra <peterz@...radead.org>,
        linux-kernel@...r.kernel.org, lkp@...ts.01.org,
        Andy Lutomirski <luto@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [LTP] [PATCH] syscall/ptrace08: Simplify the test.

Hi!
> This is failing on our 4.4 and 4.15 kernels, though they passed with the
> previous test and have commit f67b15037a7a applied.
> 
> So, this is dependent on some other behavior/commit that has changed. It passes
> on 5.4, for example. I'll try to investigate further.

We are looking at it now in SUSE, looks like the initial fix to the
kernel postponed the check to the write to the dr7 that enabled the
breakpoint, so when the dr0 wasn't enabled you could write anything
there.

Also looks like somehow the EINVAL is not propagated into the POKEUSER
call to the dr7 as it should have been.

-- 
Cyril Hrubis
chrubis@...e.cz