linux-kernel - Re: [PATCH] x86/entry/64: Context-track syscalls before enabling interrupts

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: <20150818221623.GA12858@lerouge>
Date:	Wed, 19 Aug 2015 00:16:26 +0200
From:	Frederic Weisbecker <fweisbec@...il.com>
To:	Andy Lutomirski <luto@...nel.org>
Cc:	X86 ML <x86@...nel.org>, Sasha Levin <sasha.levin@...cle.com>,
	Brian Gerst <brgerst@...il.com>,
	Denys Vlasenko <dvlasenk@...hat.com>,
	linux-kernel@...r.kernel.org, Oleg Nesterov <oleg@...hat.com>,
	Borislav Petkov <bp@...en8.de>
Subject: Re: [PATCH] x86/entry/64: Context-track syscalls before enabling
 interrupts

On Tue, Aug 18, 2015 at 12:11:59PM -0700, Andy Lutomirski wrote:
> This fixes a couple minor holes if we took an IRQ very early in syscall
> processing:
> 
>  - We could enter the IRQ with CONTEXT_USER.  Everything worked (RCU
>    was fine), but we could warn if all the debugging options were
>    set.

So this is fixing issues after your changes that call user_exit() from
IRQs, right?

But the IRQs aren't supposed to call user_exit(), they have their own hooks.
That's where the real issue is.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/