From: ebiederm@xmission.com (Eric W. Biederman)
To: Jan Engelhardt <jengelh@linux01.gwdg.de>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Miklos Szeredi <miklos@szeredi.hu>,
serue@us.ibm.com, viro@ftp.linux.org.uk, linuxram@us.ibm.com,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
containers@lists.osdl.org
Subject: Re: [patch 7/8] allow unprivileged mounts
Date: Sat, 21 Apr 2007 10:57:10 -0600 [thread overview]
Message-ID: <m1zm51is2h.fsf@ebiederm.dsl.xmission.com> (raw)
In-Reply-To: <Pine.LNX.4.61.0704211743100.9989@yvahk01.tjqt.qr> (Jan Engelhardt's message of "Sat, 21 Apr 2007 17:43:28 +0200 (MEST)")
Jan Engelhardt <jengelh@linux01.gwdg.de> writes:
> On Apr 21 2007 08:10, Eric W. Biederman wrote:
>>>
>>>> Define a new fs flag FS_SAFE, which denotes, that unprivileged
>>>> mounting of this filesystem may not constitute a security problem.
>>>>
>>>> Since most filesystems haven't been designed with unprivileged
>>>> mounting in mind, a thorough audit is needed before setting this flag.
>>>
>>> Practically speaking, is there any realistic likelihood that any filesystem
>>> apart from FUSE will ever use this?
>>
>>Also potentially some of the kernel virtual filesystems. /proc should
>>be safe already. If you don't have any kind of backing store this problem
>>gets easier.
>
> tmpfs!
tmpfs is a possible problem because it can consume lots of ram/swap. Which
is why it has limits on the amount of space it can consume. Those are set as
mount options as I recall. Which means that we would need to do something
different with respect to limits before tmpfs could become safe for
an untrusted user to mount.
Still it's close.
Eric
next prev parent reply other threads:[~2007-04-21 16:59 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-04-20 10:25 [patch 0/8] mount ownership and unprivileged mount syscall (v4) Miklos Szeredi
2007-04-20 10:25 ` [patch 1/8] add user mounts to the kernel Miklos Szeredi
2007-04-21 7:55 ` Andrew Morton
2007-04-21 8:06 ` Miklos Szeredi
2007-04-21 13:14 ` Eric W. Biederman
2007-04-22 7:02 ` Miklos Szeredi
2007-04-22 7:43 ` Eric W. Biederman
2007-04-22 8:05 ` Miklos Szeredi
2007-04-22 16:22 ` Miklos Szeredi
2007-04-20 10:25 ` [patch 2/8] allow unprivileged umount Miklos Szeredi
2007-04-21 7:55 ` Andrew Morton
2007-04-21 8:01 ` H. Peter Anvin
2007-04-21 8:09 ` Miklos Szeredi
2007-04-21 8:36 ` Andrew Morton
2007-04-21 12:53 ` Eric W. Biederman
2007-04-22 6:47 ` Miklos Szeredi
2007-04-22 7:09 ` Eric W. Biederman
2007-04-22 7:32 ` Miklos Szeredi
2007-04-21 13:29 ` Eric W. Biederman
2007-04-22 7:05 ` Miklos Szeredi
2007-04-20 10:25 ` [patch 3/8] account user mounts Miklos Szeredi
2007-04-21 7:55 ` Andrew Morton
2007-04-21 13:37 ` Eric W. Biederman
2007-04-22 7:10 ` Miklos Szeredi
2007-04-22 7:49 ` Eric W. Biederman
2007-04-22 8:08 ` Miklos Szeredi
2007-04-20 10:25 ` [patch 4/8] propagate error values from clone_mnt Miklos Szeredi
2007-04-21 13:40 ` Eric W. Biederman
2007-04-20 10:25 ` [patch 5/8] allow unprivileged bind mounts Miklos Szeredi
2007-04-21 14:00 ` Eric W. Biederman
2007-04-22 7:19 ` Miklos Szeredi
2007-04-20 10:25 ` [patch 6/8] put declaration of put_filesystem() in fs.h Miklos Szeredi
2007-04-20 10:25 ` [patch 7/8] allow unprivileged mounts Miklos Szeredi
2007-04-21 7:55 ` Andrew Morton
2007-04-21 8:13 ` Miklos Szeredi
2007-04-21 8:23 ` Miklos Szeredi
2007-04-21 14:10 ` Eric W. Biederman
2007-04-21 15:43 ` Jan Engelhardt
2007-04-21 16:57 ` Eric W. Biederman [this message]
2007-04-21 17:10 ` Jan Engelhardt
2007-04-21 21:00 ` Eric W. Biederman
2007-04-22 8:19 ` Miklos Szeredi
2007-04-21 22:06 ` Andi Kleen
2007-04-21 21:33 ` Eric W. Biederman
2007-04-22 0:46 ` Shaya Potter
2007-04-20 10:25 ` [patch 8/8] allow unprivileged fuse mounts Miklos Szeredi
2007-04-21 7:55 ` Andrew Morton
2007-04-21 8:16 ` Miklos Szeredi
2007-04-21 14:18 ` Eric W. Biederman
2007-04-22 7:22 ` Miklos Szeredi
2007-04-20 12:42 ` [patch 0/8] mount ownership and unprivileged mount syscall (v4) Serge E. Hallyn
2007-04-20 16:33 ` Eric W. Biederman
2007-04-25 0:04 ` Karel Zak
2007-04-25 1:04 ` Eric W. Biederman
2007-04-25 7:18 ` Miklos Szeredi
2007-04-25 9:23 ` Karel Zak
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