From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753453AbdBVAPV (ORCPT ); Tue, 21 Feb 2017 19:15:21 -0500 Received: from mx1.mpynet.fi ([82.197.21.84]:51831 "EHLO mx1.mpynet.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752298AbdBVAPN (ORCPT ); Tue, 21 Feb 2017 19:15:13 -0500 X-Greylist: delayed 467 seconds by postgrey-1.27 at vger.kernel.org; Tue, 21 Feb 2017 19:15:13 EST From: Tuomas Tynkkynen To: Alexander Viro CC: , Eric Van Hensbergen , , , "Aneesh Kumar K . V" , Tuomas Tynkkynen , Subject: [PATCH] fs/9p: Compare qid.path in v9fs_test_inode Date: Wed, 22 Feb 2017 02:06:29 +0200 Message-ID: <20170222000629.7995-1-tuomas@tuxera.com> X-Mailer: git-send-email 2.11.1 MIME-Version: 1.0 Content-Type: text/plain X-ClientProxiedBy: tuxera-exch.ad.tuxera.com (10.20.48.11) To tuxera-exch.ad.tuxera.com (10.20.48.11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit fd2421f54423 ("fs/9p: When doing inode lookup compare qid details and inode mode bits.") transformed v9fs_qid_iget() to use iget5_locked() instead of iget_locked(). However, the test() callback is not checking fid.path at all, which means that a lookup in the inode cache can now accidentally locate a completely wrong inode from the same inode hash bucket if the other fields (qid.type and qid.version) match. Fixes: fd2421f54423 ("fs/9p: When doing inode lookup compare qid details and inode mode bits.") Cc: stable@vger.kernel.org Signed-off-by: Tuomas Tynkkynen --- Does this sound sensible? I have never reproduced the problem myself but reportedly this patch solves some really weird problems where the symptoms match (wrong files being opened unpredictably). --- fs/9p/vfs_inode.c | 3 +++ fs/9p/vfs_inode_dotl.c | 3 +++ 2 files changed, 6 insertions(+) diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index 30ca770c5e0b..f8ab4a66acaf 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -483,6 +483,9 @@ static int v9fs_test_inode(struct inode *inode, void *data) if (v9inode->qid.type != st->qid.type) return 0; + + if (v9inode->qid.path != st->qid.path) + return 0; return 1; } diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c index afaa4b6de801..c3dd0d42bb3a 100644 --- a/fs/9p/vfs_inode_dotl.c +++ b/fs/9p/vfs_inode_dotl.c @@ -87,6 +87,9 @@ static int v9fs_test_inode_dotl(struct inode *inode, void *data) if (v9inode->qid.type != st->qid.type) return 0; + + if (v9inode->qid.path != st->qid.path) + return 0; return 1; } -- 2.11.1