linux-kernel - Re: [PATCH v2 1/2] um: Set secure access mode for temporary 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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <566449A3.6030504@digikod.net>
Date:	Sun, 6 Dec 2015 15:43:47 +0100
From:	Mickaël Salaün <mic@...ikod.net>
To:	Tristan Schmelcher <tschmelcher@...gle.com>
Cc:	linux-kernel@...r.kernel.org, Jeff Dike <jdike@...toit.com>,
	Richard Weinberger <richard@....at>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	user-mode-linux-devel <user-mode-linux-devel@...ts.sourceforge.net>,
	user-mode-linux-user@...ts.sourceforge.net
Subject: Re: [PATCH v2 1/2] um: Set secure access mode for temporary file

On 06/12/2015 12:32, Mickaël Salaün wrote:
> On 04/12/2015 18:13, Tristan Schmelcher wrote:
>> If there is a concern that the mkstemp implementation may be insecure,
>> why not set and restore the umask?
>>
> 
> I will add this safeguard.

Well, I'm concerned to use umask because it is not thread-safe and drivers may use create_mem_file() in a multi-theaded context. I prefer to stick to fchmod and handle the race-condition with O_TMPFILE unsell someone is sure that this will not create bugs :)

 Mickaël


Download attachment "signature.asc" of type "application/pgp-signature" (456 bytes)