From owner-dev-commits-src-all@freebsd.org Wed Apr 14 07:59:14 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 89B115CD910; Wed, 14 Apr 2021 07:59:14 +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 4FKvxt3DnPz4gpV; Wed, 14 Apr 2021 07:59:14 +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 609CE19DE2; Wed, 14 Apr 2021 07:59:14 +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 13E7xEJQ007279; Wed, 14 Apr 2021 07:59:14 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 13E7xEoV007278; Wed, 14 Apr 2021 07:59:14 GMT (envelope-from git) Date: Wed, 14 Apr 2021 07:59:14 GMT Message-Id: <202104140759.13E7xEoV007278@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Konstantin Belousov Subject: git: 75c5cf7a720f - main - filt_timerexpire: avoid process lock recursion MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: kib X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 75c5cf7a720f5a73f17aff60adbc4a7b2fa86f84 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: Wed, 14 Apr 2021 07:59:14 -0000 The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=75c5cf7a720f5a73f17aff60adbc4a7b2fa86f84 commit 75c5cf7a720f5a73f17aff60adbc4a7b2fa86f84 Author: Konstantin Belousov AuthorDate: 2021-04-13 14:25:11 +0000 Commit: Konstantin Belousov CommitDate: 2021-04-14 07:53:28 +0000 filt_timerexpire: avoid process lock recursion Found by: syzkaller Reported and reviewed by: markj Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D29746 --- sys/kern/kern_event.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) diff --git a/sys/kern/kern_event.c b/sys/kern/kern_event.c index 31b091e20984..45d505fca757 100644 --- a/sys/kern/kern_event.c +++ b/sys/kern/kern_event.c @@ -161,6 +161,7 @@ static void filt_procdetach(struct knote *kn); static int filt_proc(struct knote *kn, long hint); static int filt_fileattach(struct knote *kn); static void filt_timerexpire(void *knx); +static void filt_timerexpire_l(struct knote *kn, bool proc_locked); static int filt_timerattach(struct knote *kn); static void filt_timerdetach(struct knote *kn); static void filt_timerstart(struct knote *kn, sbintime_t to); @@ -706,21 +707,19 @@ kqtimer_proc_continue(struct proc *p) TAILQ_FOREACH_SAFE(kc, &p->p_kqtim_stop, link, kc1) { TAILQ_REMOVE(&p->p_kqtim_stop, kc, link); if (kc->next <= now) - filt_timerexpire(kc->kn); + filt_timerexpire_l(kc->kn, true); else kqtimer_sched_callout(kc); } } static void -filt_timerexpire(void *knx) +filt_timerexpire_l(struct knote *kn, bool proc_locked) { - struct knote *kn; struct kq_timer_cb_data *kc; struct proc *p; sbintime_t now; - kn = knx; kc = kn->kn_ptr.p_v; if ((kn->kn_flags & EV_ONESHOT) != 0 || kc->to == 0) { @@ -742,17 +741,26 @@ filt_timerexpire(void *knx) */ p = kc->p; if (P_SHOULDSTOP(p) || P_KILLED(p)) { - PROC_LOCK(p); + if (!proc_locked) + PROC_LOCK(p); if (P_SHOULDSTOP(p) || P_KILLED(p)) { TAILQ_INSERT_TAIL(&p->p_kqtim_stop, kc, link); - PROC_UNLOCK(p); + if (!proc_locked) + PROC_UNLOCK(p); return; } - PROC_UNLOCK(p); + if (!proc_locked) + PROC_UNLOCK(p); } kqtimer_sched_callout(kc); } +static void +filt_timerexpire(void *knx) +{ + filt_timerexpire_l(knx, false); +} + /* * data contains amount of time to sleep */