From owner-dev-commits-src-branches@freebsd.org Tue Apr 6 19:20:13 2021 Return-Path: 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 3CF605B57F8; Tue, 6 Apr 2021 19:20:13 +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 4FFHRJ3b5mz4dPd; Tue, 6 Apr 2021 19:20:12 +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 C251911C16; Tue, 6 Apr 2021 19:20:07 +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 136JK7Kg000944; Tue, 6 Apr 2021 19:20:07 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 136JK78P000942; Tue, 6 Apr 2021 19:20:07 GMT (envelope-from git) Date: Tue, 6 Apr 2021 19:20:07 GMT Message-Id: <202104061920.136JK78P000942@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Mark Johnston Subject: git: 6f7815083ad6 - stable/11 - 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/stable/11 X-Git-Reftype: branch X-Git-Commit: 6f7815083ad66c34bad0dfa08c7033ff670b3be1 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 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 06 Apr 2021 19:20:13 -0000 The branch stable/11 has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=6f7815083ad66c34bad0dfa08c7033ff670b3be1 commit 6f7815083ad66c34bad0dfa08c7033ff670b3be1 Author: Mark Johnston AuthorDate: 2021-04-06 19:09:43 +0000 Commit: Mark Johnston CommitDate: 2021-04-06 19:09:43 +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 --- 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 7885052c27d6..613872303982 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.