From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-2228598-1527604941-2-4080745212365784816 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no ("Email failed DMARC policy for domain") X-Spam-charsets: X-IgnoreVacation: yes ("Email failed DMARC policy for domain") X-Resolved-to: linux@kroah.com X-Delivered-to: linux@kroah.com X-Mail-from: linux-fsdevel-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=fm2; t= 1527604941; b=NqLgD2JCREb3a6wwmSlws+t3XOqsIdyQ2TORe5fN1X59OlcN7v kf++XVixkH1PuZrQ/7Swez8DoFqEBXTKmrc90LFgk99J18NmYcHUclhPoJxP7flv 8Ftm4TwMunzzE8W/FjV9n4t1GapqXkas2936JL16FmuQnXHLTTXLzQr7bVvI0m1+ 1lxYCHc6rk9OMsMLr/683WynnZaqm9s6dKpqPWu1UaPmEQRkjMjaUBc0xbMJRpBy a6ypIr4MQccp9QuSFDTn3Q1WxsmIHmpjmj2BDZEWHgIznGpWKd7y0D3pJjeESHTa s03hOcTFv7s2Nn5XcvEhyiEcxYNS3fBun4cg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:sender:list-id; s=fm2; t=1527604941; bh= iehAG4s408LqtFAVcD/jVCvfKtvn+GFiDM89ZuQvj8w=; b=XpqXPnr0f6BxIgai PCtQDwRiANUFGoP9KzBcCQgL/P0VkYSjsYt3dWj3N+XPpf1IIT9C8+FzlDuqKDJi SPLXMDbvFT7LpRHDdDySpSPQmO6H1RmbRhB/I4qw9trqkpqbcDolKWfrym8xdjIE Q33oUeTYHdg0FJDnxRwurdv6pzvyH88Qx3fELy+Bnbd6sp8dXN5nNtcuj4gMzndD dkpk3hpXNeiYImHtL1eK4NiITUg4ufni9T2btcgK4xTxY99USdYdl8nKOFcyIk67 qo+9Chw942W2bjt7gi9SVzqmYaZ3wiEOM6SS4x/D43JtFxXksXvIToyAEfCxhqzd UfYIbw== ARC-Authentication-Results: i=1; mx3.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=fail (p=none,has-list-id=yes,d=none) header.from=redhat.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-fsdevel-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-google-dkim=pass (2048-bit rsa key) header.d=1e100.net header.i=@1e100.net header.b=hMWmJRWp; x-ptr=pass smtp.helo=vger.kernel.org policy.ptr=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=redhat.com header.result=pass header_is_org_domain=yes; x-vs=clean score=0 state=0 Authentication-Results: mx3.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=fail (p=none,has-list-id=yes,d=none) header.from=redhat.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-fsdevel-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-google-dkim=pass (2048-bit rsa key) header.d=1e100.net header.i=@1e100.net header.b=hMWmJRWp; x-ptr=pass smtp.helo=vger.kernel.org policy.ptr=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=redhat.com header.result=pass header_is_org_domain=yes; x-vs=clean score=0 state=0 X-ME-VSCategory: clean X-CM-Envelope: MS4wfCvqa4kRg4mril5RnD7Xb9+Dy3Lu3XBIjzA7IagfYXo//M/KrY2SC4pLir/PBLIQzcLmpsXD09t6YQtp5M2/LO9leYmfqzucnCjDVkvRXul1vnd/9oxe qEeRZTkUIkC47shaJw3TlU7FS4/IzBQ2PAc/DazryUnUctRCW0BkVPR1TMyE3JNeHrbCv87vaVmPmDVTvg7nRGyo7awv+VDW6FDK3TtnrS+60uUz08PAJAR6 X-CM-Analysis: v=2.3 cv=Tq3Iegfh c=1 sm=1 tr=0 a=UK1r566ZdBxH71SXbqIOeA==:117 a=UK1r566ZdBxH71SXbqIOeA==:17 a=VUJBJC2UJ8kA:10 a=pGLkceISAAAA:8 a=drOt6m5kAAAA:8 a=20KFwNOVAAAA:8 a=IXLtcRePUa_BfBxVTWsA:9 a=RMMjzBEyIzXRtoq5n5K6:22 X-ME-CMScore: 0 X-ME-CMCategory: none Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935131AbeE2OmF (ORCPT ); Tue, 29 May 2018 10:42:05 -0400 Received: from mail-wr0-f196.google.com ([209.85.128.196]:35152 "EHLO mail-wr0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935107AbeE2Ol5 (ORCPT ); Tue, 29 May 2018 10:41:57 -0400 X-Google-Smtp-Source: AB8JxZquq7qyRCODMnHPZJjONX3ZCf8sivCGcBviAZhXaNFONt3lH2y+93NU0yureA+hT5OEP1koVw== From: Miklos Szeredi To: linux-unionfs@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 07/11] ovl: make ovl_create_real() cope with vfs_mkdir() safely Date: Tue, 29 May 2018 16:41:39 +0200 Message-Id: <20180529144143.16378-8-mszeredi@redhat.com> X-Mailer: git-send-email 2.14.3 In-Reply-To: <20180529144143.16378-1-mszeredi@redhat.com> References: <20180529144143.16378-1-mszeredi@redhat.com> Sender: linux-fsdevel-owner@vger.kernel.org X-Mailing-List: linux-fsdevel@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: From: Amir Goldstein vfs_mkdir() may succeed and leave the dentry passed to it unhashed and negative. ovl_create_real() is the last caller breaking when that happens. [amir: split re-factoring of ovl_create_temp() to prep patch add comment about unhashed dir after mkdir add pr_warn() if mkdir succeeds and lookup fails] Signed-off-by: Al Viro Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi --- fs/overlayfs/dir.c | 35 +++++++++++++++++++++++++++++++++-- 1 file changed, 33 insertions(+), 2 deletions(-) diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index 1b181292a624..b33d37d1a87c 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -114,6 +114,37 @@ int ovl_cleanup_and_whiteout(struct dentry *workdir, struct inode *dir, goto out; } +static struct dentry *ovl_mkdir_real(struct inode *dir, struct dentry *dentry, + umode_t mode) +{ + int err; + + err = ovl_do_mkdir(dir, dentry, mode); + if (err) { + dput(dentry); + return ERR_PTR(err); + } + + /* + * vfs_mkdir() may succeed and leave the dentry passed + * to it unhashed and negative. If that happens, try to + * lookup a new hashed and positive dentry. + */ + if (unlikely(d_unhashed(dentry))) { + struct dentry *d; + + d = lookup_one_len(dentry->d_name.name, dentry->d_parent, + dentry->d_name.len); + if (IS_ERR(d)) { + pr_warn("overlayfs: failed lookup after mkdir (%pd2, err=%i).\n", + dentry, err); + } + dput(dentry); + dentry = d; + } + return dentry; +} + struct dentry *ovl_create_real(struct inode *dir, struct dentry *newdentry, struct ovl_cattr *attr) { @@ -135,8 +166,8 @@ struct dentry *ovl_create_real(struct inode *dir, struct dentry *newdentry, break; case S_IFDIR: - err = ovl_do_mkdir(dir, newdentry, attr->mode); - break; + /* mkdir is special... */ + return ovl_mkdir_real(dir, newdentry, attr->mode); case S_IFCHR: case S_IFBLK: -- 2.14.3