Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753616AbZCRRJK (ORCPT ); Wed, 18 Mar 2009 13:09:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753394AbZCRRIw (ORCPT ); Wed, 18 Mar 2009 13:08:52 -0400 Received: from e32.co.us.ibm.com ([32.97.110.150]:52801 "EHLO e32.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753866AbZCRRIv (ORCPT ); Wed, 18 Mar 2009 13:08:51 -0400 Date: Wed, 18 Mar 2009 12:08:43 -0500 From: "Serge E. Hallyn" To: "J. Bruce Fields" Cc: Linus Torvalds , linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, Igor Zhbanov , "J. Bruce Fields" , stable@kernel.org Subject: Re: [PATCH] nfsd: nfsd should drop CAP_MKNOD for non-root Message-ID: <20090318170843.GA29045@us.ibm.com> References: <1237393292-14934-1-git-send-email-bfields@fieldses.org> <1237393292-14934-2-git-send-email-bfields@fieldses.org> <1237393292-14934-3-git-send-email-bfields@fieldses.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1237393292-14934-3-git-send-email-bfields@fieldses.org> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2202 Lines: 57 Quoting J. Bruce Fields (bfields@fieldses.org): > From: J. Bruce Fields > > Since creating a device node is normally an operation requiring special > privilege, Igor Zhbanov points out that it is surprising (to say the > least) that a client can, for example, create a device node on a > filesystem exported with root_squash. > > So, make sure CAP_MKNOD is among the capabilities dropped when an nfsd > thread handles a request from a non-root user. > > Reported-by: Igor Zhbanov > Cc: stable@kernel.org > Signed-off-by: J. Bruce Fields Acked-by: Serge Hallyn I assume CAP_LINUX_IMMUTABLE simply does not apply to nfs? And, you're adding CAP_FS_MASK_B1 in anticipation of labeled nfs? Though, I was going to send a patch later today or tomorrow (figure I should do some ltp testing) adding CAP_MKNOD to the whole CAP_FS_MASK_B0 (and CAP_LINUX_IMMUTABLE and CAP_FS_MASK_B1 to CAP_FS_SET). That will conflict with this one. thanks, -serge > --- > include/linux/capability.h | 6 ++++-- > 1 files changed, 4 insertions(+), 2 deletions(-) > > diff --git a/include/linux/capability.h b/include/linux/capability.h > index 1b98725..4864a43 100644 > --- a/include/linux/capability.h > +++ b/include/linux/capability.h > @@ -393,8 +393,10 @@ struct cpu_vfs_cap_data { > # define CAP_FULL_SET ((kernel_cap_t){{ ~0, ~0 }}) > # define CAP_INIT_EFF_SET ((kernel_cap_t){{ ~CAP_TO_MASK(CAP_SETPCAP), ~0 }}) > # define CAP_FS_SET ((kernel_cap_t){{ CAP_FS_MASK_B0, CAP_FS_MASK_B1 } }) > -# define CAP_NFSD_SET ((kernel_cap_t){{ CAP_FS_MASK_B0|CAP_TO_MASK(CAP_SYS_RESOURCE), \ > - CAP_FS_MASK_B1 } }) > +# define CAP_NFSD_SET ((kernel_cap_t){{ CAP_FS_MASK_B0 \ > + | CAP_TO_MASK(CAP_SYS_RESOURCE) \ > + | CAP_TO_MASK(CAP_MKNOD), \ > + CAP_FS_MASK_B1 } }) > > #endif /* _KERNEL_CAPABILITY_U32S != 2 */ > > -- > 1.6.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/