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: <20150923095022.GB640@swordfish>
Date:	Wed, 23 Sep 2015 18:50:22 +0900
From:	Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>
To:	Michal Hocko <mhocko@...nel.org>
Cc:	Vladimir Davydov <vdavydov@...allels.com>,
	Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>,
	David Rientjes <rientjes@...gle.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Oleg Nesterov <oleg@...hat.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Kyle Walker <kwalker@...hat.com>,
	Christoph Lameter <cl@...ux.com>,
	Johannes Weiner <hannes@...xchg.org>,
	linux-mm <linux-mm@...ck.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Stanislav Kozina <skozina@...hat.com>,
	Tetsuo Handa <penguin-kernel@...ove.sakura.ne.jp>
Subject: Re: [patch] mm, oom: remove task_lock protecting comm printing

On (09/23/15 11:43), Michal Hocko wrote:
[..]
> > > the previous name was already null terminated,
> > 
> > Yeah, but if the old name is shorter than the new one, set_task_comm()
> > overwrites the terminating null of the old name before writing the new
> > terminating null, so there is a short time window during which tsk->comm
> > might be not null-terminated, no?
> 
> Not really:
>         case PR_SET_NAME:
>                 comm[sizeof(me->comm) - 1] = 0;
>                 if (strncpy_from_user(comm, (char __user *)arg2,
>                                       sizeof(me->comm) - 1) < 0)
>                         return -EFAULT;
> 
> So it first writes the terminating 0 and only then starts copying.

right.

hm, shouldn't set_task_comm()->__set_task_comm() do the same?

	-ss
--
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/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ