Re: VFS, NFS security bug? Should CAP_MKNOD and CAP_LINUX_IMMUTABLE be added to CAP_FS_MASK?

From: Michael Kerrisk
Date: Thu Mar 12 2009 - 16:21:34 EST


On Fri, Mar 13, 2009 at 5:10 AM, Serge E. Hallyn <serue@xxxxxxxxxx> wrote:
> Quoting J. Bruce Fields (bfields@xxxxxxxxxxxx):
>> On Wed, Mar 11, 2009 at 03:53:34PM +0300, Igor Zhbanov wrote:
>> > Hello!
>> >
>> > It seems that CAP_MKNOD and CAP_LINUX_IMMUTABLE were forgotten to be
>> > added to CAP_FS_MASK_B0 in linux-2.6.x and to CAP_FS_MASK in
>> > linux-2.4.x. Both capabilities affects file system and can be
>> > considered file system capabilities.
>>
>> Sounds right to me--I'd expect rootsquash to guarantee that new device
>> nodes can't be created from the network.  Cc'ing random people from the
>> git log for include/linux/capability.h in hopes they can help.
>
> Yeah it seems reasonable.  If it is, then does that mean that we
> also need CAP_SYS_ADMIN (to write selinux labels) and CAP_SETFCAP
> (to set file capabilities) as well?

If a change is made to CAP_FS_MASK, please do remember to CC
mtk.manpages@xxxxxxxxx, and linux-api@.

Cheers,

Michael


--
Michael Kerrisk Linux man-pages maintainer;
http://www.kernel.org/doc/man-pages/ Found a documentation bug?
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