linux-kernel - Re: [PATCH] mmap: add sysctl for controlling ~VM

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: <CAB=4xhqu1FsJnNbHNeokyROvEFpRJYKhcHRLLw5QTVKOkbkWfQ@mail.gmail.com>
Date:	Tue, 16 Aug 2011 10:07:46 -0700
From:	Roland McGrath <mcgrathr@...gle.com>
To:	Mel Gorman <mel@....ul.ie>
Cc:	Will Drewry <wad@...omium.org>, linux-kernel@...r.kernel.org,
	Ingo Molnar <mingo@...e.hu>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Al Viro <viro@...iv.linux.org.uk>,
	Eric Paris <eparis@...hat.com>,
	Andrea Arcangeli <aarcange@...hat.com>,
	Rik van Riel <riel@...hat.com>,
	Nitin Gupta <ngupta@...are.org>,
	Hugh Dickins <hughd@...gle.com>,
	Shaohua Li <shaohua.li@...el.com>, linux-mm@...ck.org
Subject: Re: [PATCH] mmap: add sysctl for controlling ~VM_MAYEXEC taint

On Tue, Aug 16, 2011 at 2:33 AM, Mel Gorman <mel@....ul.ie> wrote:
> Is using shm_open()+mmap instead of open()+mmap() to open a file on
> /dev/shm really that difficult?
>
> int shm_open(const char *name, int oflag, mode_t mode);
> int open(const char *pathname, int flags, mode_t mode);

I cannot figure out the rationale behind this question at all.
Both of these library functions result in the same system call.

> An ordinary user is not going to know that a segfault from an
> application can be fixed with this sysctl. This looks like something
> that should be fixed in the library so that it can work on kernels
> that do not have the sysctl.

I think the expectation is that the administrator or system builder
who decides to set the (non-default) noexec mount option will also
set the sysctl at the same time.


Thanks,
Roland
--
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/