From patchwork Fri May 8 18:45:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Eric W. Biederman" X-Patchwork-Id: 11537445 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D8C9914B4 for ; Fri, 8 May 2020 18:49:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CA55A218AC for ; Fri, 8 May 2020 18:49:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726863AbgEHStZ (ORCPT ); Fri, 8 May 2020 14:49:25 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:38412 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726767AbgEHStZ (ORCPT ); Fri, 8 May 2020 14:49:25 -0400 Received: from in01.mta.xmission.com ([166.70.13.51]) by out02.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jX83n-00046H-SA; Fri, 08 May 2020 12:49:23 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95] helo=x220.xmission.com) by in01.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.87) (envelope-from ) id 1jX83n-00031t-5l; Fri, 08 May 2020 12:49:23 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Cc: Linus Torvalds , Oleg Nesterov , Jann Horn , Kees Cook , Greg Ungerer , Rob Landley , Bernd Edlinger , , Al Viro , Alexey Dobriyan , Andrew Morton References: <87h7wujhmz.fsf@x220.int.ebiederm.org> <87sgga6ze4.fsf@x220.int.ebiederm.org> Date: Fri, 08 May 2020 13:45:56 -0500 In-Reply-To: <87sgga6ze4.fsf@x220.int.ebiederm.org> (Eric W. Biederman's message of "Fri, 08 May 2020 13:43:31 -0500") Message-ID: <875zd66za3.fsf_-_@x220.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 X-XM-SPF: eid=1jX83n-00031t-5l;;;mid=<875zd66za3.fsf_-_@x220.int.ebiederm.org>;;;hst=in01.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1+AXon5dcUfjuMt0Bp8k9tiBqs0tFK9Qcg= 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=2.0 required=8.0 tests=ALL_TRUSTED,BAYES_50, DCC_CHECK_NEGATIVE,T_TooManySym_01,XMNoVowels,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: 0.5000] * 1.5 XMNoVowels Alpha-numberic number with no vowels * 0.7 XMSubLong Long Subject * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa07 0; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject X-Spam-DCC: ; sa07 0; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: **; X-Spam-Relay-Country: X-Spam-Timing: total 282 ms - load_scoreonly_sql: 0.03 (0.0%), signal_user_changed: 11 (3.8%), b_tie_ro: 9 (3.3%), parse: 0.85 (0.3%), extract_message_metadata: 10 (3.6%), get_uri_detail_list: 0.77 (0.3%), tests_pri_-1000: 13 (4.7%), tests_pri_-950: 1.24 (0.4%), tests_pri_-900: 1.01 (0.4%), tests_pri_-90: 74 (26.1%), check_bayes: 72 (25.6%), b_tokenize: 6 (2.0%), b_tok_get_all: 4.5 (1.6%), b_comp_prob: 1.85 (0.7%), b_tok_touch_all: 57 (20.3%), b_finish: 0.81 (0.3%), tests_pri_0: 159 (56.4%), check_dkim_signature: 0.48 (0.2%), check_dkim_adsp: 2.2 (0.8%), poll_dns_idle: 0.52 (0.2%), tests_pri_10: 2.1 (0.7%), tests_pri_500: 7 (2.6%), rewrite_mail: 0.00 (0.0%) Subject: [PATCH 4/6] exec: Run sync_mm_rss before taking exec_update_mutex 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-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Like exec_mm_release sync_mm_rss is about flushing out the state of the old_mm, which does not need to happen under exec_update_mutex. Make this explicit by moving sync_mm_rss outside of exec_update_mutex. Signed-off-by: "Eric W. Biederman" Reviewed-by: Kees Cook --- fs/exec.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/exec.c b/fs/exec.c index 11a5c073aa35..15682a1dfee9 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1051,13 +1051,14 @@ static int exec_mmap(struct mm_struct *mm) tsk = current; old_mm = current->mm; exec_mm_release(tsk, old_mm); + if (old_mm) + sync_mm_rss(old_mm); ret = mutex_lock_killable(&tsk->signal->exec_update_mutex); if (ret) return ret; if (old_mm) { - sync_mm_rss(old_mm); /* * Make sure that if there is a core dump in progress * for the old mm, we get out and die instead of going