From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 12 Dec 2018 19:02:28 -0800 From: Matthew Wilcox Subject: Re: [RFC PATCH v1 0/5] Add support for O_MAYEXEC Message-ID: <20181213030228.GM6830@bombadil.infradead.org> References: <20181212081712.32347-1-mic@digikod.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20181212081712.32347-1-mic@digikod.net> To: =?iso-8859-1?Q?Micka=EBl_Sala=FCn?= Cc: linux-kernel@vger.kernel.org, Al Viro , James Morris , Jonathan Corbet , Kees Cook , Matthew Garrett , Michael Kerrisk , =?iso-8859-1?Q?Micka=EBl_Sala=FCn?= , Mimi Zohar , Philippe =?iso-8859-1?Q?Tr=E9buchet?= , Shuah Khan , Thibaut Sautereau , Vincent Strubel , Yves-Alexis Perez , kernel-hardening@lists.openwall.com, linux-api@vger.kernel.org, linux-security-module@vger.kernel.org, linux-fsdevel@vger.kernel.org List-ID: On Wed, Dec 12, 2018 at 09:17:07AM +0100, Mickaël Salaün wrote: > The goal of this patch series is to control script interpretation. A > new O_MAYEXEC flag used by sys_open() is added to enable userland script > interpreter to delegate to the kernel (and thus the system security > policy) the permission to interpret scripts or other files containing > what can be seen as commands. I don't have a problem with the concept, but we're running low on O_ bits. Does this have to be done before the process gets a file descriptor, or could we have a new syscall? Since we're going to be changing the interpreters anyway, it doesn't seem like too much of an imposition to ask them to use: int verify_for_exec(int fd) instead of adding an O_MAYEXEC.