From patchwork Thu Sep 23 07:13:39 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ian Kent X-Patchwork-Id: 12512099 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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 480E0C433F5 for ; Thu, 23 Sep 2021 07:20:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 26B94610A0 for ; Thu, 23 Sep 2021 07:20:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239559AbhIWHVn (ORCPT ); Thu, 23 Sep 2021 03:21:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32782 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234343AbhIWHVn (ORCPT ); Thu, 23 Sep 2021 03:21:43 -0400 X-Greylist: delayed 387 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Thu, 23 Sep 2021 00:20:12 PDT Received: from smtp01.aussiebb.com.au (smtp01.aussiebb.com.au [IPv6:2403:5800:3:25::1001]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 31156C061574; Thu, 23 Sep 2021 00:20:12 -0700 (PDT) Received: from localhost (localhost.localdomain [127.0.0.1]) by smtp01.aussiebb.com.au (Postfix) with ESMTP id 7F7CA100266; Thu, 23 Sep 2021 17:13:40 +1000 (AEST) X-Virus-Scanned: Debian amavisd-new at smtp01.aussiebb.com.au Received: from smtp01.aussiebb.com.au ([127.0.0.1]) by localhost (smtp01.aussiebb.com.au [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id uORAQQHh4x1W; Thu, 23 Sep 2021 17:13:40 +1000 (AEST) Received: by smtp01.aussiebb.com.au (Postfix, from userid 116) id 6D4D9100278; Thu, 23 Sep 2021 17:13:40 +1000 (AEST) Received: from mickey.themaw.net (unknown [100.72.131.210]) by smtp01.aussiebb.com.au (Postfix) with ESMTP id C556C100266; Thu, 23 Sep 2021 17:13:39 +1000 (AEST) Subject: [PATCH] autofs: fix wait name hash calculation in autofs_wait() From: Ian Kent To: Al Viro , autofs mailing list , Kernel Mailing List , linux-fsdevel Date: Thu, 23 Sep 2021 15:13:39 +0800 Message-ID: <163238121836.315941.18066358755443618960.stgit@mickey.themaw.net> User-Agent: StGit/0.23 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org There's a mistake in commit 2be7828c9fefc ("get rid of autofs_getpath()") that affects kernels from v5.13.0, basically missed because of me not fully testing the change for Al. The problem is that the hash calculation for the wait name qstr hasn't been updated to account for the change to use dentry_path_raw(). This prevents the correct matching an existing wait resulting in multiple notifications being sent to the daemon for the same mount which must not occur. The problem wasn't discovered earlier because it only occurs when multiple processes trigger a request for the same mount concurrently so it only shows up in more aggressive testing. Fixes: 2be7828c9fefc ("get rid of autofs_getpath()") Cc: stable@vger.kernel.org Signed-off-by: Ian Kent --- fs/autofs/waitq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/autofs/waitq.c b/fs/autofs/waitq.c index 16b5fca0626e..54c1f8b8b075 100644 --- a/fs/autofs/waitq.c +++ b/fs/autofs/waitq.c @@ -358,7 +358,7 @@ int autofs_wait(struct autofs_sb_info *sbi, qstr.len = strlen(p); offset = p - name; } - qstr.hash = full_name_hash(dentry, name, qstr.len); + qstr.hash = full_name_hash(dentry, qstr.name, qstr.len); if (mutex_lock_interruptible(&sbi->wq_mutex)) { kfree(name);