From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Fri, 4 Dec 2015 14:07:36 -0600 From: "Serge E. Hallyn" To: Theodore Ts'o , "Serge E. Hallyn" , Seth Forshee , "Eric W. Biederman" , Alexander Viro , Serge Hallyn , Richard Weinberger , Austin S Hemmelgarn , Miklos Szeredi , linux-bcache@vger.kernel.org, dm-devel@redhat.com, linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, linux-fsdevel@vger.kernel.org, fuse-devel@lists.sourceforge.net, linux-security-module@vger.kernel.org, selinux@tycho.nsa.gov Subject: Re: [PATCH 14/19] fs: Permit FIBMAP for users with CAP_SYS_RAWIO in s_user_ns Message-ID: <20151204200736.GJ3624@mail.hallyn.com> References: <1449070821-73820-1-git-send-email-seth.forshee@canonical.com> <1449070821-73820-15-git-send-email-seth.forshee@canonical.com> <20151204191143.GE3624@mail.hallyn.com> <20151204200528.GC18359@thunk.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151204200528.GC18359@thunk.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: Heh, I was looking over http://www.gossamer-threads.com/lists/linux/kernel/103611 a little while ago :) The same question was asked 16 years ago. Apparently the answer then was that it was easier than fixing the code. Quoting Theodore Ts'o (tytso@mit.edu): > The fact that we need CAP_SYS_RAIO for FIBMAP is pretty silly, given > that FIEMAP does not require privileges --- and in fact the preferred > interface. Why not just simply drop the requirement for privileges > for FIBMAP? > > (Seth, Serge, this isn't a real objection to your patch; but the fact > that FIBMAP requires root has always been a bit silly, and this would > be a great opportunity to simplify things a bit.) > > - Ted > > > On Fri, Dec 04, 2015 at 01:11:43PM -0600, Serge E. Hallyn wrote: > > Quoting Seth Forshee (seth.forshee@canonical.com): > > > Signed-off-by: Seth Forshee > > > > Acked-by: Serge Hallyn > > > > > --- > > > fs/ioctl.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/fs/ioctl.c b/fs/ioctl.c > > > index 5d01d2638ca5..45c371bed7ee 100644 > > > --- a/fs/ioctl.c > > > +++ b/fs/ioctl.c > > > @@ -55,7 +55,7 @@ static int ioctl_fibmap(struct file *filp, int __user *p) > > > /* do we support this mess? */ > > > if (!mapping->a_ops->bmap) > > > return -EINVAL; > > > - if (!capable(CAP_SYS_RAWIO)) > > > + if (!ns_capable(filp->f_inode->i_sb->s_user_ns, CAP_SYS_RAWIO)) > > > return -EPERM; > > > res = get_user(block, p); > > > if (res) > > > -- > > > 1.9.1 > > > > > > -- > > > 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/ > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html