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Biederman) To: Alexey Gladkov Cc: LKML , Linux FS Devel , Alexey Gladkov , Alexander Viro , Kees Cook References: Date: Mon, 22 Feb 2021 09:44:40 -0600 In-Reply-To: (Alexey Gladkov's message of "Wed, 17 Feb 2021 09:21:40 +0100") Message-ID: 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=1lEDOK-001Z2V-UG;;;mid=;;;hst=in02.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX18UX+qcoGNY+o+bfYPzgo2AhKFciywhCUM= 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 sa07.xmission.com X-Spam-Level: X-Spam-Status: No, score=0.5 required=8.0 tests=ALL_TRUSTED,BAYES_50, DCC_CHECK_NEGATIVE,T_TM2_M_HEADER_IN_MSG,XMSubLong 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: 0.4934] * 0.7 XMSubLong Long Subject * 0.0 T_TM2_M_HEADER_IN_MSG BODY: No description available. * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa07 1397; Body=1 Fuz1=1 Fuz2=1] X-Spam-DCC: XMission; sa07 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;Alexey Gladkov X-Spam-Relay-Country: X-Spam-Timing: total 294 ms - load_scoreonly_sql: 0.33 (0.1%), signal_user_changed: 11 (3.9%), b_tie_ro: 9 (3.0%), parse: 1.01 (0.3%), extract_message_metadata: 3.1 (1.1%), get_uri_detail_list: 0.73 (0.2%), tests_pri_-1000: 4.6 (1.6%), tests_pri_-950: 1.52 (0.5%), tests_pri_-900: 1.62 (0.6%), tests_pri_-90: 70 (23.9%), check_bayes: 68 (23.3%), b_tokenize: 6 (1.9%), b_tok_get_all: 4.7 (1.6%), b_comp_prob: 2.2 (0.7%), b_tok_touch_all: 52 (17.8%), b_finish: 1.14 (0.4%), tests_pri_0: 179 (61.0%), check_dkim_signature: 1.09 (0.4%), check_dkim_adsp: 3.2 (1.1%), poll_dns_idle: 0.99 (0.3%), tests_pri_10: 2.2 (0.8%), tests_pri_500: 8 (2.7%), rewrite_mail: 0.00 (0.0%) Subject: Re: [RESEND PATCH v4 0/3] proc: Relax check of mount visibility X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Alexey Gladkov writes: > If only the dynamic part of procfs is mounted (subset=pid), then there is no > need to check if procfs is fully visible to the user in the new user > namespace. A couple of things. 1) Allowing the mount should come in the last patch. So we don't have a bisect hazard. 2) We should document that we still require a mount of proc to match on atime and readonly mount attributes. 3) If we can find a way to safely not require a previous mount of proc this will be much more valuable. Eric