linux-kernel - [PATCH AUTOSEL 4.14 5/8] configfs_register_group() shouldn't be (and isn't) called in rmdirable parts

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon,  9 Sep 2019 11:41:42 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Al Viro <viro@...iv.linux.org.uk>, Christoph Hellwig <hch@....de>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH AUTOSEL 4.14 5/8] configfs_register_group() shouldn't be (and isn't) called in rmdirable parts

From: Al Viro <viro@...iv.linux.org.uk>

[ Upstream commit f19e4ed1e1edbfa3c9ccb9fed17759b7d6db24c6 ]

revert cc57c07343bd "configfs: fix registered group removal"
It was an attempt to handle something that fundamentally doesn't
work - configfs_register_group() should never be done in a part
of tree that can be rmdir'ed.  And in mainline it never had been,
so let's not borrow trouble; the fix was racy anyway, it would take
a lot more to make that work and desired semantics is not clear.

Signed-off-by: Al Viro <viro@...iv.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@....de>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 fs/configfs/dir.c | 11 -----------
 1 file changed, 11 deletions(-)

diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index a1985a9ad2d64..64fdb12e6ad61 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -1782,16 +1782,6 @@ void configfs_unregister_group(struct config_group *group)
 	struct dentry *dentry = group->cg_item.ci_dentry;
 	struct dentry *parent = group->cg_item.ci_parent->ci_dentry;
 
-	mutex_lock(&subsys->su_mutex);
-	if (!group->cg_item.ci_parent->ci_group) {
-		/*
-		 * The parent has already been unlinked and detached
-		 * due to a rmdir.
-		 */
-		goto unlink_group;
-	}
-	mutex_unlock(&subsys->su_mutex);
-
 	inode_lock_nested(d_inode(parent), I_MUTEX_PARENT);
 	spin_lock(&configfs_dirent_lock);
 	configfs_detach_prep(dentry, NULL);
@@ -1806,7 +1796,6 @@ void configfs_unregister_group(struct config_group *group)
 	dput(dentry);
 
 	mutex_lock(&subsys->su_mutex);
-unlink_group:
 	unlink_group(group);
 	mutex_unlock(&subsys->su_mutex);
 }
-- 
2.20.1