From owner-dev-commits-src-all@freebsd.org Tue Feb 23 01:04:38 2021 Return-Path: Delivered-To: dev-commits-src-all@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 3FDC2555CE1; Tue, 23 Feb 2021 01:04:38 +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 4Dl16Z1PzDz3N0c; Tue, 23 Feb 2021 01:04:38 +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 236637A6F; Tue, 23 Feb 2021 01:04:38 +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 11N14cRX003616; Tue, 23 Feb 2021 01:04:38 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 11N14caN003615; Tue, 23 Feb 2021 01:04:38 GMT (envelope-from git) Date: Tue, 23 Feb 2021 01:04:38 GMT Message-Id: <202102230104.11N14caN003615@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Jamie Gritton Subject: git: 0a2a96f35a4c - main - jail: Don't allow jails under dying parents MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: jamie X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 0a2a96f35a4c2dab3486438680fa289e12971e4b Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-all@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commit messages for all branches of the src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 23 Feb 2021 01:04:38 -0000 The branch main has been updated by jamie: URL: https://cgit.FreeBSD.org/src/commit/?id=0a2a96f35a4c2dab3486438680fa289e12971e4b commit 0a2a96f35a4c2dab3486438680fa289e12971e4b Author: Jamie Gritton AuthorDate: 2021-02-23 01:04:06 +0000 Commit: Jamie Gritton CommitDate: 2021-02-23 01:04:06 +0000 jail: Don't allow jails under dying parents If a jail is created with jail_set(...JAIL_DYING), and it has a parent currently in a dying state, that will bring the parent jail back to life. Restrict that to require that the parent itself be explicitly brought back first, and not implicitly created along with the new child jail. Differential Revision: https://reviews.freebsd.org/D28515 --- sys/kern/kern_jail.c | 40 +++++++++++++++++----------------------- 1 file changed, 17 insertions(+), 23 deletions(-) diff --git a/sys/kern/kern_jail.c b/sys/kern/kern_jail.c index 89dd039685a8..4f434637ccfa 100644 --- a/sys/kern/kern_jail.c +++ b/sys/kern/kern_jail.c @@ -990,7 +990,6 @@ kern_jail_set(struct thread *td, struct uio *optuio, int flags) * This abuses the file error codes ENOENT and EEXIST. */ pr = NULL; - ppr = mypr; inspr = NULL; if (cuflags == JAIL_CREATE && jid == 0 && name != NULL) { namelc = strrchr(name, '.'); @@ -999,6 +998,12 @@ kern_jail_set(struct thread *td, struct uio *optuio, int flags) jid = 0; } sx_xlock(&allprison_lock); + ppr = mypr; + if (!prison_isalive(ppr)) { + /* This jail is dying. This process will surely follow. */ + error = EAGAIN; + goto done_deref; + } drflags = PD_LIST_XLOCKED; if (jid != 0) { if (jid < 0) { @@ -1022,7 +1027,6 @@ kern_jail_set(struct thread *td, struct uio *optuio, int flags) break; } if (pr != NULL) { - ppr = pr->pr_parent; /* Create: jid must not exist. */ if (cuflags == JAIL_CREATE) { /* @@ -1044,6 +1048,13 @@ kern_jail_set(struct thread *td, struct uio *optuio, int flags) vfs_opterror(opts, "jail %d not found", jid); goto done_deref; } + ppr = pr->pr_parent; + if (!prison_isalive(ppr)) { + error = ENOENT; + vfs_opterror(opts, "jail %d is dying", + ppr->pr_id); + goto done_deref; + } if (!prison_isalive(pr)) { if (!(flags & JAIL_DYING)) { error = ENOENT; @@ -1109,15 +1120,13 @@ kern_jail_set(struct thread *td, struct uio *optuio, int flags) "jail \"%s\" not found", name); goto done_deref; } - if (!(flags & JAIL_DYING) && - !prison_isalive(ppr)) { - mtx_unlock(&ppr->pr_mtx); + mtx_unlock(&ppr->pr_mtx); + if (!prison_isalive(ppr)) { error = ENOENT; vfs_opterror(opts, "jail \"%s\" is dying", name); goto done_deref; } - mtx_unlock(&ppr->pr_mtx); *namelc = '.'; } namelc++; @@ -1196,26 +1205,9 @@ kern_jail_set(struct thread *td, struct uio *optuio, int flags) vfs_opterror(opts, "prison limit exceeded"); goto done_deref; } - prison_hold(ppr); - if (!refcount_acquire_if_not_zero(&ppr->pr_uref)) { - /* This brings the parent back to life. */ - mtx_lock(&ppr->pr_mtx); - refcount_acquire(&ppr->pr_uref); - ppr->pr_state = PRISON_STATE_ALIVE; - mtx_unlock(&ppr->pr_mtx); - error = osd_jail_call(ppr, PR_METHOD_CREATE, opts); - if (error) { - pr = ppr; - drflags |= PD_DEREF | PD_DEUREF; - goto done_deref; - } - } - if (jid == 0 && (jid = get_next_prid(&inspr)) == 0) { error = EAGAIN; vfs_opterror(opts, "no available jail IDs"); - pr = ppr; - drflags |= PD_DEREF | PD_DEUREF; goto done_deref; } @@ -1235,6 +1227,8 @@ kern_jail_set(struct thread *td, struct uio *optuio, int flags) TAILQ_INSERT_TAIL(&allprison, pr, pr_list); pr->pr_parent = ppr; + prison_hold(ppr); + prison_proc_hold(ppr); LIST_INSERT_HEAD(&ppr->pr_children, pr, pr_sibling); for (tpr = ppr; tpr != NULL; tpr = tpr->pr_parent) tpr->pr_childcount++;