From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-1511654-1518326196-2-15844572322983660781 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.001, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES enro, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='uk', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1518326196; b=sRPbqXcsCHiEZtmg9Nl1Qv7uW4lWh/GC1tHnYOjQcwQiyV9 oZt1JDAFCOP+k9NyNMfRm2Rd7Nu15kwjVAguB2boXmJURpshoBiIJM9YcJfFg45C D0dIo6frsofsxf546BZpBLCdiNOvSM5ZHxFpL/4sxbYnznpR65i8sUneMhf3AxiX GUVO7apqvMToeyBsSB/Cfj/Ts1npdlEz4+M2fIb4M8G43ua6CU3FW911YfqR5UvV Ffe9R00pi6qYL1vvpPMyVGevAvPZhSyk/W3vAiSSH+9Bo2VWos8K3lsvR/DrQ5/r oEH2CUmwF376QadBppx0yOBJk2hOglyNwKp2mpw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=content-type:content-transfer-encoding :mime-version:from:to:cc:date:message-id:subject:in-reply-to :sender:list-id; s=arctest; t=1518326196; bh=bz7RY+J4nbHl+RQN/vt Y+CZtb3+Duycr5U5TFqY+2g0=; b=D2SMxUf4y0pECGkPW82udQanenSmEqaZ/lp 5k+aZCBn2kLTRPWkVgt07dvnQOYV5z9RfwEPULVOfyV8saUGkmufsVPy9WogZctQ lpsT0gVV/cVlsizGaxAGlKW7LjAR0mtBQZKn94b9al39xpyxzVW4rlvWe4iJ6v2D 25+x8HK7wNLUmb0FtyYGpRUmxZ+tQe7mkyYT1PDs6THrlPlABidKF8gHL7WB0las DeR8BOPikP+1Z4STgcKJgZ2nHBQZWt19n63DUfA0T8d7Yngzm3HJlNgWQPVu5zZr +Nou9/c0zTPJGuDJCQiuJzceanF8P4WsvG7/W54sU9lbxdOTrog== ARC-Authentication-Results: i=1; mx2.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=decadent.org.uk; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=decadent.org.uk header.result=pass header_is_org_domain=yes Authentication-Results: mx2.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=decadent.org.uk; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=decadent.org.uk header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753834AbeBKFOS (ORCPT ); Sun, 11 Feb 2018 00:14:18 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:41383 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752611AbeBKEdl (ORCPT ); Sat, 10 Feb 2018 23:33:41 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Ian Kent" , "Al Viro" Date: Sun, 11 Feb 2018 04:20:06 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 49/79] autofs4: autofs4_wait() vs. autofs4_catatonic_mode() race In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 3.2.99-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Al Viro commit 4041bcdc7bef06a2fb29c57394c713a74bd13b08 upstream. We need to recheck ->catatonic after autofs4_wait() got ->wq_mutex for good, or we might end up with wq inserted into queue after autofs4_catatonic_mode() had done its thing. It will stick there forever, since there won't be anything to clear its ->name.name. A bit of a complication: validate_request() drops and regains ->wq_mutex. It actually ends up the most convenient place to stick the check into... Acked-by: Ian Kent Signed-off-by: Al Viro Signed-off-by: Ben Hutchings --- fs/autofs4/waitq.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/fs/autofs4/waitq.c +++ b/fs/autofs4/waitq.c @@ -257,6 +257,9 @@ static int validate_request(struct autof struct autofs_wait_queue *wq; struct autofs_info *ino; + if (sbi->catatonic) + return -ENOENT; + /* Wait in progress, continue; */ wq = autofs4_find_wait(sbi, qstr); if (wq) { @@ -289,6 +292,9 @@ static int validate_request(struct autof if (mutex_lock_interruptible(&sbi->wq_mutex)) return -EINTR; + if (sbi->catatonic) + return -ENOENT; + wq = autofs4_find_wait(sbi, qstr); if (wq) { *wait = wq; @@ -389,7 +395,7 @@ int autofs4_wait(struct autofs_sb_info * ret = validate_request(&wq, sbi, &qstr, dentry, notify); if (ret <= 0) { - if (ret == 0) + if (ret != -EINTR) mutex_unlock(&sbi->wq_mutex); kfree(qstr.name); return ret;