linux-kernel - [RFC PATCH 3/6] landlock: explicitly skip mediation of O

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]

Message-ID: <20250312212148.274205-4-ryan.lee@canonical.com>
Date: Wed, 12 Mar 2025 14:21:43 -0700
From: Ryan Lee <ryan.lee@...onical.com>
To: linux-fsdevel@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	apparmor@...ts.ubuntu.com,
	linux-security-module@...r.kernel.org,
	selinux@...r.kernel.org
Cc: Ryan Lee <ryan.lee@...onical.com>,
	Alexander Viro <viro@...iv.linux.org.uk>,
	Christian Brauner <brauner@...nel.org>,
	Jan Kara <jack@...e.cz>,
	John Johansen <john.johansen@...onical.com>,
	Paul Moore <paul@...l-moore.com>,
	James Morris <jmorris@...ei.org>,
	"Serge E. Hallyn" <serge@...lyn.com>,
	Mickaël Salaün <mic@...ikod.net>,
	Günther Noack <gnoack@...gle.com>,
	Stephen Smalley <stephen.smalley.work@...il.com>,
	Ondrej Mosnacek <omosnace@...hat.com>,
	Casey Schaufler <casey@...aufler-ca.com>,
	Kentaro Takeda <takedakn@...data.co.jp>,
	Tetsuo Handa <penguin-kernel@...ove.SAKURA.ne.jp>
Subject: [RFC PATCH 3/6] landlock: explicitly skip mediation of O_PATH file descriptors

Landlock currently does not have handling of O_PATH fds. Now that they
are being passed to the file_open hook, explicitly skip mediation of
them until we can handle them.

Signed-off-by: Ryan Lee <ryan.lee@...onical.com>
---
 security/landlock/fs.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/security/landlock/fs.c b/security/landlock/fs.c
index 0804f76a67be..37b2167bf4c6 100644
--- a/security/landlock/fs.c
+++ b/security/landlock/fs.c
@@ -1522,6 +1522,14 @@ static int hook_file_open(struct file *const file)
 	if (!dom)
 		return 0;
 
+	/*
+	 * Preserve the behavior of O_PATH fd creation not being mediated, for
+	 * now.  Remove this when the comment below about handling O_PATH fds
+	 * is resolved.
+	 */
+	if (file->f_flags & O_PATH)
+		return 0;
+
 	/*
 	 * Because a file may be opened with O_PATH, get_required_file_open_access()
 	 * may return 0.  This case will be handled with a future Landlock
-- 
2.43.0

base-kernel: v6.14-rc6