From: Al Viro <viro@ZenIV.linux.org.uk>
To: Eric Paris <eparis@redhat.com>
Cc: linux-kernel@vger.kernel.org, alan <alan@redhat.com>,
aviro@redhat.com, drepper@redhat.com, hch@infradead.org,
sds@tycho.nsa.gov, jmorris@namei.org
Subject: Re: [RFC] correct flags to f_mode conversion in __dentry_open
Date: Wed, 12 Mar 2008 18:34:41 +0000 [thread overview]
Message-ID: <20080312183441.GJ27894@ZenIV.linux.org.uk> (raw)
In-Reply-To: <1205346327.5297.232.camel@localhost.localdomain>
On Wed, Mar 12, 2008 at 02:25:27PM -0400, Eric Paris wrote:
> I recently tried to add an SELinux BUG_ON in the case where the kernel
> made a permission request for no permissions and was able to stumble
> over it with something as simple as
>
> open("/dev/null", 3);
>
> Notice that 3 == (O_RDWR | O_WRONLY)
>
> First question, is 3 ever a valid flag from from userspace to sys_open?
Yes. "Check for both read and write permissions, set neither FMODE_READ
nor FMODE_WRITE".
Don't break drivers, please - some use that for "ioctl-only" opens,
with special semantics for those.
next prev parent reply other threads:[~2008-03-12 18:34 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-12 18:25 [RFC] correct flags to f_mode conversion in __dentry_open Eric Paris
2008-03-12 18:34 ` Al Viro [this message]
2008-03-12 18:41 ` Eric Paris
2008-03-12 18:47 ` Andreas Schwab
2008-03-15 21:59 ` Alan Cox
2008-03-15 22:00 ` Alexander Viro
2008-03-17 10:45 ` Christoph Hellwig
2008-05-21 17:54 ` Michael Kerrisk
2008-05-22 2:10 ` James Morris
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