linux-ext4 - Re: [PATCH] ioctl_getfsmap.2: document the GETFSMAP ioctl

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 8 May 2017 00:17:53 +0200
From:   Jann Horn <jannh@...gle.com>
To:     "Darrick J. Wong" <darrick.wong@...cle.com>
Cc:     Michael Kerrisk-manpages <mtk.manpages@...il.com>,
        linux-xfs@...r.kernel.org, linux-fsdevel@...r.kernel.org,
        linux-ext4@...r.kernel.org, Linux API <linux-api@...r.kernel.org>,
        linux-man@...r.kernel.org
Subject: Re: [PATCH] ioctl_getfsmap.2: document the GETFSMAP ioctl

On Sun, May 7, 2017 at 5:58 PM, Darrick J. Wong <darrick.wong@...cle.com> wrote:
> Document the new GETFSMAP ioctl that returns the physical layout of a
> (disk-based) filesystem.
[...]
> +.B EPERM
> +This query is not allowed.

Please document the circumstances under which a query is allowed.

Also: From a quick glance at the XFS implementation, I don't see any
privilege checks. Am I missing something, or does this API permit an
unprivileged user to determine the number of physical blocks allocated
for any inode, even for inodes the user can't ordinarily see in any
way?