linux-kernel - Re: + c-r-prctl-add-ability-to-set-new-mm_struct-exe_file-update-after-mm- num_exe_file

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]

Date:	Fri, 20 Apr 2012 00:29:50 +0200
From:	Oleg Nesterov <oleg@...hat.com>
To:	Konstantin Khlebnikov <khlebnikov@...nvz.org>
Cc:	Cyrill Gorcunov <gorcunov@...nvz.org>,
	"akpm@...ux-foundation.org" <akpm@...ux-foundation.org>,
	"keescook@...omium.org" <keescook@...omium.org>,
	"kosaki.motohiro@...fujitsu.com" <kosaki.motohiro@...fujitsu.com>,
	"matthltc@...ibm.com" <matthltc@...ibm.com>,
	"tj@...nel.org" <tj@...nel.org>,
	Pavel Emelianov <xemul@...allels.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: +
	c-r-prctl-add-ability-to-set-new-mm_struct-exe_file-update-after-mm-
	num_exe_file_vmas-removal.patch added to -mm tree

On 04/20, Konstantin Khlebnikov wrote:
>
>>> My question is: unless I missed something "it can't be changed again"
>>> is not actually true. A task does PR_SET_MM_EXE_FILE, then it forks
>>> the new child. The child can do PR_SET_MM_EXE_FILE again. Is this
>>> by design?
>>
>> Hmm, not sure, Konstantin?
>
> Why not? It has new pid, why it cannot change exe_file?

OK, if you do not see a problem - I agree with this patch.

I don't really understand what PR_SET_MM_EXE_FILE buys us if
parent/child can have different /proc/pid/exe links without
exec, but

> Actually I don't care too.

same here ;)

and at least this addresses the "establishes a bound on how
frequently the symlink can change" from Matt.

Oleg.

--
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/