linux-kernel - Re: [PATCH 3/3] posix timers: Add syscall that works on timer sigevent

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: <51212734.2060700@parallels.com>
Date:	Sun, 17 Feb 2013 22:53:40 +0400
From:	Pavel Emelyanov <xemul@...allels.com>
To:	Jann Horn <jannhorn@...glemail.com>
CC:	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Michael Kerrisk <mtk.manpages@...il.com>,
	linux-api@...r.kernel.org,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 3/3] posix timers: Add syscall that works on timer sigevent

On 02/17/2013 05:42 PM, Jann Horn wrote:
> On Thu, Feb 14, 2013 at 08:19:45PM +0400, Pavel Emelyanov wrote:
>> +	struct sigevent event;
> [...]
>> +	event.sigev_notify = timer->it_sigev_notify;
>> +	event.sigev_signo = timer->sigq->info.si_signo;
>> +	event.sigev_value = timer->sigq->info.si_value;
>> +	event.sigev_notify_thread_id = pid_vnr(timer->it_pid);
> [...]
>> +	if (old_event && copy_to_user(old_event, &event, sizeof(event)))
> 
> Won't this leak uninitialized kernel stack data to userspace? As far as I can
> see, the _sigev_un union is bigger than the _tid field in it, so the rest of
> it will be copied over without initialization, right?

Indeed :( Thanks for catching this, I will memezro the thing before copying
to the user-space.

> Jann
> 


--
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/