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Biederman) To: Miklos Szeredi Cc: linux-unionfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org References: <20191025112917.22518-1-mszeredi@redhat.com> Date: Fri, 25 Oct 2019 08:42:24 -0500 In-Reply-To: <20191025112917.22518-1-mszeredi@redhat.com> (Miklos Szeredi's message of "Fri, 25 Oct 2019 13:29:12 +0200") Message-ID: <87r231rlfj.fsf@x220.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1iNzsG-0006vL-SW;;;mid=<87r231rlfj.fsf@x220.int.ebiederm.org>;;;hst=in01.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX19PFgdLj+d0f0xnbf++PpDtbqlJ7o3tTO0= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on sa05.xmission.com X-Spam-Level: * X-Spam-Status: No, score=1.3 required=8.0 tests=ALL_TRUSTED,BAYES_50, DCC_CHECK_NEGATIVE,T_TM2_M_HEADER_IN_MSG,XMNoVowels autolearn=disabled version=3.4.2 X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.4944] * 1.5 XMNoVowels Alpha-numberic number with no vowels * 0.0 T_TM2_M_HEADER_IN_MSG BODY: No description available. * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa05 1397; Body=1 Fuz1=1 Fuz2=1] X-Spam-DCC: XMission; sa05 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: *;Miklos Szeredi X-Spam-Relay-Country: X-Spam-Timing: total 365 ms - load_scoreonly_sql: 0.05 (0.0%), signal_user_changed: 3.8 (1.0%), b_tie_ro: 2.5 (0.7%), parse: 1.31 (0.4%), extract_message_metadata: 4.8 (1.3%), get_uri_detail_list: 1.73 (0.5%), tests_pri_-1000: 6 (1.5%), tests_pri_-950: 1.88 (0.5%), tests_pri_-900: 1.48 (0.4%), tests_pri_-90: 24 (6.5%), check_bayes: 22 (6.0%), b_tokenize: 8 (2.3%), b_tok_get_all: 6 (1.6%), b_comp_prob: 2.5 (0.7%), b_tok_touch_all: 2.7 (0.7%), b_finish: 0.75 (0.2%), tests_pri_0: 300 (82.3%), check_dkim_signature: 0.62 (0.2%), check_dkim_adsp: 2.4 (0.7%), poll_dns_idle: 0.52 (0.1%), tests_pri_10: 2.5 (0.7%), tests_pri_500: 8 (2.1%), rewrite_mail: 0.00 (0.0%) Subject: Re: [RFC PATCH 0/5] allow unprivileged overlay mounts X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Miklos Szeredi writes: > Hi Eric, > > Can you please have a look at this patchset? > > The most interesting one is the last oneliner adding FS_USERNS_MOUNT; > whether I'm correct in stating that this isn't going to introduce any > holes, or not... I will take some time and dig through this. From a robustness standpoint I worry about the stackable filesystem side. As that is uniquely an attack vector with overlayfs. There is definitely demand for this. > Thanks, > Miklos > > --- > Miklos Szeredi (5): > ovl: document permission model > ovl: ignore failure to copy up unknown xattrs > vfs: allow unprivileged whiteout creation > ovl: user xattr > ovl: unprivieged mounts > > Documentation/filesystems/overlayfs.txt | 44 +++++++++++++ > fs/char_dev.c | 3 + > fs/namei.c | 17 ++--- > fs/overlayfs/copy_up.c | 34 +++++++--- > fs/overlayfs/dir.c | 2 +- > fs/overlayfs/export.c | 2 +- > fs/overlayfs/inode.c | 39 ++++++------ > fs/overlayfs/namei.c | 56 +++++++++-------- > fs/overlayfs/overlayfs.h | 81 +++++++++++++++--------- > fs/overlayfs/ovl_entry.h | 1 + > fs/overlayfs/readdir.c | 5 +- > fs/overlayfs/super.c | 53 +++++++++++----- > fs/overlayfs/util.c | 82 +++++++++++++++++++++---- > include/linux/device_cgroup.h | 3 + > 14 files changed, 298 insertions(+), 124 deletions(-) Eric