From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.7 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5CC39C34056 for ; Wed, 19 Feb 2020 19:02:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 303D124673 for ; Wed, 19 Feb 2020 19:02:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=tycho-ws.20150623.gappssmtp.com header.i=@tycho-ws.20150623.gappssmtp.com header.b="lLfi6cyM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726739AbgBSTCC (ORCPT ); Wed, 19 Feb 2020 14:02:02 -0500 Received: from mail-pf1-f196.google.com ([209.85.210.196]:34779 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726613AbgBSTCC (ORCPT ); Wed, 19 Feb 2020 14:02:02 -0500 Received: by mail-pf1-f196.google.com with SMTP id i6so535740pfc.1 for ; Wed, 19 Feb 2020 11:02:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tycho-ws.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=Gaq6NM5o+UM+pFOLAVDFZv0/RMH6toB+rITqZIOsMYE=; b=lLfi6cyMIxFEgNuwaGXNFp+Ts5Y/KtKR4ejCootJgO0ckrc0gRvgZ7nZudfZhjQoBI Q+Knj9pxcd3wq4LHf974POD/1Hnc1WLhh+kb4jKuK0df5rwk2iv1uTnor3Qx5iHTuPG0 6K4HnlgfXU5h6k7AIRjJaZLVQOz6UOuRrMgB8+OAD6HMboRGS5lIdf7dZ6Ucih5+R7Yl Rog2cqFxxqxQHrPhjPpD2KCEN9OsLng7bSpIYqsSPDMDkmsISBpLWbLW2+0qZvzT1V07 z5vq1ehXDwR3+F8rgzV7zl1I6T57sNXV+zO+rlE6KPJkoXVN3bBVWhpnq9CEo2lp5Kyv f3fg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=Gaq6NM5o+UM+pFOLAVDFZv0/RMH6toB+rITqZIOsMYE=; b=P2UUelsZHqNY/bvDy0gM1Csddmw62xD5ZzUV9d3rHrjodGA5OTMpf5MUkxQo5S52Q4 8JrhBqYp/l6BMFvTUoVrmJ/VfH7wMKmzibNWghyu5U7osHdhi46b4R0wYTTIBLnNDO6S 5ULLMaP5z5Vxb1Tp6axWEomX6xAL85xRDBxQ+WFKqMuB6da8NIJfJ3Si8ZlP10eFRfdL 52WIBCmZbKA7dYdTNChaUUghfzTa8LiYhb7QtdOAuFxfHhiJffMkm6jB3IOoO+dM0LCL lQi36GaF1as4b38uhQgBpbRj9vxGVT2N+oVQcXBXcHiX+x0OboKZ4x0Hry0dPrkD/WBR dXIg== X-Gm-Message-State: APjAAAVdLwzyD0ycRcHa/RV1K4UtWWQoy03rHB/8zn9xN2osY5357Xvz 4LxNkKzcCZABpNcVTCHc1Me3sKCGs7o= X-Google-Smtp-Source: APXvYqzL9QHxtjM0arkcSibiR2+WuYV6t3I4blhYPV4i/x7bknHVO47R8L1k55I3DTecqOfiHbMLSg== X-Received: by 2002:a63:ba19:: with SMTP id k25mr30971648pgf.333.1582138921637; Wed, 19 Feb 2020 11:02:01 -0800 (PST) Received: from cisco.hsd1.co.comcast.net ([2001:420:c0c8:1007::7a1]) by smtp.gmail.com with ESMTPSA id q12sm345195pfh.158.2020.02.19.11.01.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 Feb 2020 11:02:00 -0800 (PST) From: Tycho Andersen To: cgroups@vger.kernel.org Cc: Li Zefan , Johannes Weiner , Tejun Heo , Serge Hallyn , linux-kernel@vger.kernel.org, Tycho Andersen Subject: [PATCH] cgroup1: don't call release_agent when it is "" Date: Wed, 19 Feb 2020 12:01:29 -0700 Message-Id: <20200219190129.6899-1-tycho@tycho.ws> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Older (and maybe current) versions of systemd set release_agent to "" when shutting down, but do not set notify_on_release to 0. Since 64e90a8acb85 ("Introduce STATIC_USERMODEHELPER to mediate call_usermodehelper()"), we filter out such calls when the user mode helper path is "". However, when used in conjunction with an actual (i.e. non "") STATIC_USERMODEHELPER, the path is never "", so the real usermode helper will be called with argv[0] == "". Let's avoid this by not invoking the release_agent when it is "". Signed-off-by: Tycho Andersen --- kernel/cgroup/cgroup-v1.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c index be1a1c83cdd1..b3626c3c6f92 100644 --- a/kernel/cgroup/cgroup-v1.c +++ b/kernel/cgroup/cgroup-v1.c @@ -782,7 +782,7 @@ void cgroup1_release_agent(struct work_struct *work) pathbuf = kmalloc(PATH_MAX, GFP_KERNEL); agentbuf = kstrdup(cgrp->root->release_agent_path, GFP_KERNEL); - if (!pathbuf || !agentbuf) + if (!pathbuf || !agentbuf || !strlen(agentbuf)) goto out; spin_lock_irq(&css_set_lock); -- 2.20.1