linux-kernel - Re: [PATCH] fcntl.h: define AT

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]

Message-ID: <hqikut$4ts$1@taverner.cs.berkeley.edu>
Date:	Mon, 19 Apr 2010 22:20:13 +0000 (UTC)
From:	daw@...berkeley.edu (David Wagner)
To:	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] fcntl.h: define AT_EACCESS

Can you share some justification why it's worth extending
faccessat() with new options?

Isn't faccessat() insecure in most use cases, due to TOCTTOU
(time-of-check to time-of-use) vulnerabilities?  When faccessat()
returns 0, you learn that at some point in the past, the process had
permission to access a given file, though the process may or may not
have permission at the moment.  Why is that a useful thing to know?

I'm sure you're familiar with all the standard arguments why using
access() tends to represent a security vulnerability.  Is there a reason
why similar arguments do not apply to faccessat()?
--
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/