From patchwork Sat Mar 26 21:10:00 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Theodore Ts'o X-Patchwork-Id: 8674931 Return-Path: X-Original-To: patchwork-linux-fsdevel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 4FD1AC0553 for ; Sat, 26 Mar 2016 21:10:27 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 49651201BB for ; Sat, 26 Mar 2016 21:10:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6E1D520160 for ; Sat, 26 Mar 2016 21:10:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754153AbcCZVKS (ORCPT ); Sat, 26 Mar 2016 17:10:18 -0400 Received: from imap.thunk.org ([74.207.234.97]:34238 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753466AbcCZVKQ (ORCPT ); Sat, 26 Mar 2016 17:10:16 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=thunk.org; s=ef5046eb; h=References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From; bh=+0ncstlYs3dDrkA1LB6yvgHqSGctzqzMsxqL2oA4sgY=; b=QuGZRqEdzgg8QVpLf0KZcnyyrwZKwgBi3cQi6odyFyxdqKGfpqnxTE9eIOc1BGYLPC60BdkqquVO32QQEBpNE4qWNGyRc0Ianve9Mi1HX5EiYGxp2p2lTQexF5RPFddBFecXkhbLzV/jaTCiPTqxQCc2nLsWW3wBF4zfo3EiNIQ=; Received: from root (helo=closure.thunk.org) by imap.thunk.org with local-esmtp (Exim 4.84) (envelope-from ) id 1ajvTK-0005MX-A8; Sat, 26 Mar 2016 21:10:14 +0000 Received: by closure.thunk.org (Postfix, from userid 15806) id DF91F82E1B8; Sat, 26 Mar 2016 17:10:12 -0400 (EDT) From: Theodore Ts'o To: Ext4 Developers List Cc: dhowells@redhat.com, viro@ZenIV.linux.org.uk, Linux Filesystem Development List , jaegeuk@kernel.org, Theodore Ts'o , stable@vger.kernel.org Subject: [PATCH 5/5] ext4 crypto: use dget_parent() in ext4_d_revalidate() Date: Sat, 26 Mar 2016 17:10:00 -0400 Message-Id: <1459026600-9232-6-git-send-email-tytso@mit.edu> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1459026600-9232-1-git-send-email-tytso@mit.edu> References: <1459026600-9232-1-git-send-email-tytso@mit.edu> X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: tytso@thunk.org X-SA-Exim-Scanned: No (on imap.thunk.org); SAEximRunCond expanded to false Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Spam-Status: No, score=-7.8 required=5.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD,T_DKIM_INVALID,UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This avoids potential problems caused by a race where the inode gets renamed out from its parent directory and the parent directory is deleted while ext4_d_revalidate() is running. Fixes: 28b4c263961c Reported-by: Al Viro Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org --- fs/ext4/crypto.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c index 012fd32..ea69ce4 100644 --- a/fs/ext4/crypto.c +++ b/fs/ext4/crypto.c @@ -478,13 +478,16 @@ uint32_t ext4_validate_encryption_key_size(uint32_t mode, uint32_t size) */ static int ext4_d_revalidate(struct dentry *dentry, unsigned int flags) { - struct inode *dir = d_inode(dentry->d_parent); - struct ext4_crypt_info *ci = EXT4_I(dir)->i_crypt_info; + struct dentry *dir; + struct ext4_crypt_info *ci; int dir_has_key, cached_with_key; - if (!ext4_encrypted_inode(dir)) + dir = dget_parent(dentry); + if (!ext4_encrypted_inode(d_inode(dir))) { + dput(dir); return 0; - + } + ci = EXT4_I(d_inode(dir))->i_crypt_info; if (ci && ci->ci_keyring_key && (ci->ci_keyring_key->flags & ((1 << KEY_FLAG_INVALIDATED) | (1 << KEY_FLAG_REVOKED) | @@ -494,6 +497,7 @@ static int ext4_d_revalidate(struct dentry *dentry, unsigned int flags) /* this should eventually be an flag in d_flags */ cached_with_key = dentry->d_fsdata != NULL; dir_has_key = (ci != NULL); + dput(dir); /* * If the dentry was cached without the key, and it is a