From owner-dev-commits-src-branches@freebsd.org Tue Apr 6 19:20:30 2021
Return-Path: <owner-dev-commits-src-branches@freebsd.org>
Delivered-To: dev-commits-src-branches@mailman.nyi.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1])
by mailman.nyi.freebsd.org (Postfix) with ESMTP id AF41C5B599C;
Tue, 6 Apr 2021 19:20:30 +0000 (UTC) (envelope-from git@FreeBSD.org)
Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org
[IPv6:2610:1c1:1:606c::19:3])
(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)
key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256
client-signature RSA-PSS (4096 bits) client-digest SHA256)
(Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK))
by mx1.freebsd.org (Postfix) with ESMTPS id 4FFHRd0b4yz4dTB;
Tue, 6 Apr 2021 19:20:28 +0000 (UTC) (envelope-from git@FreeBSD.org)
Received: from gitrepo.freebsd.org (gitrepo.freebsd.org
[IPv6:2610:1c1:1:6068::e6a:5])
(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)
key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256)
(Client did not present a certificate)
by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 86E3D11B2B;
Tue, 6 Apr 2021 19:20:24 +0000 (UTC) (envelope-from git@FreeBSD.org)
Received: from gitrepo.freebsd.org ([127.0.1.44])
by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 136JKOdZ006558;
Tue, 6 Apr 2021 19:20:24 GMT (envelope-from git@gitrepo.freebsd.org)
Received: (from git@localhost)
by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 136JKOtx006557;
Tue, 6 Apr 2021 19:20:24 GMT (envelope-from git)
Date: Tue, 6 Apr 2021 19:20:24 GMT
Message-Id: <202104061920.136JKOtx006557@gitrepo.freebsd.org>
To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org,
dev-commits-src-branches@FreeBSD.org
From: Mark Johnston <markj@FreeBSD.org>
Subject: git: e59bfcaa37fc - releng/11.4 - mount: Disallow mounting over a
jail root
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit
X-Git-Committer: markj
X-Git-Repository: src
X-Git-Refname: refs/heads/releng/11.4
X-Git-Reftype: branch
X-Git-Commit: e59bfcaa37fc8fe5c6e200e53aa6daa841751cb7
Auto-Submitted: auto-generated
X-BeenThere: dev-commits-src-branches@freebsd.org
X-Mailman-Version: 2.1.34
Precedence: list
List-Id: Commits to the stable branches of the FreeBSD src repository
<dev-commits-src-branches.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/dev-commits-src-branches>,
<mailto:dev-commits-src-branches-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/dev-commits-src-branches/>
List-Post: <mailto:dev-commits-src-branches@freebsd.org>
List-Help: <mailto:dev-commits-src-branches-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/dev-commits-src-branches>,
<mailto:dev-commits-src-branches-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 06 Apr 2021 19:20:31 -0000
The branch releng/11.4 has been updated by markj:
URL: https://cgit.FreeBSD.org/src/commit/?id=e59bfcaa37fc8fe5c6e200e53aa6daa841751cb7
commit e59bfcaa37fc8fe5c6e200e53aa6daa841751cb7
Author: Mark Johnston <markj@FreeBSD.org>
AuthorDate: 2021-04-06 19:09:43 +0000
Commit: Mark Johnston <markj@FreeBSD.org>
CommitDate: 2021-04-06 19:10:21 +0000
mount: Disallow mounting over a jail root
Discussed with: jamie
Approved by: so
Security: CVE-2020-25584
Security: FreeBSD-SA-21:10.jail_mount
(cherry picked from commit 6f7815083ad66c34bad0dfa08c7033ff670b3be1)
---
sys/kern/vfs_mount.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/sys/kern/vfs_mount.c b/sys/kern/vfs_mount.c
index 3e5ebe715a42..c88f2be54d02 100644
--- a/sys/kern/vfs_mount.c
+++ b/sys/kern/vfs_mount.c
@@ -830,6 +830,11 @@ vfs_domount_first(
ASSERT_VOP_ELOCKED(vp, __func__);
KASSERT((fsflags & MNT_UPDATE) == 0, ("MNT_UPDATE shouldn't be here"));
+ if (vp == td->td_ucred->cr_prison->pr_root) {
+ vput(vp);
+ return (EPERM);
+ }
+
/*
* If the user is not root, ensure that they own the directory
* onto which we are attempting to mount.