From nobody Mon Nov 01 20:00:17 2021 X-Original-To: dev-commits-src-main@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id F16B11844C9A; Mon, 1 Nov 2021 20:00:17 +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 4HjkR56Wckz4R1P; Mon, 1 Nov 2021 20:00:17 +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 C01CB17461; Mon, 1 Nov 2021 20:00:17 +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 1A1K0HOw059386; Mon, 1 Nov 2021 20:00:17 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 1A1K0Hs4059375; Mon, 1 Nov 2021 20:00:17 GMT (envelope-from git) Date: Mon, 1 Nov 2021 20:00:17 GMT Message-Id: <202111012000.1A1K0Hs4059375@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Mateusz Guzik Subject: git: edf6dd82e966 - main - pf: fix use-after-free from pf_find_state_all List-Id: Commit messages for the main branch of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-main List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-dev-commits-src-main@freebsd.org X-BeenThere: dev-commits-src-main@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: mjg X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: edf6dd82e9662b72c17483de4de5575dd5acd972 Auto-Submitted: auto-generated X-ThisMailContainsUnwantedMimeParts: N The branch main has been updated by mjg: URL: https://cgit.FreeBSD.org/src/commit/?id=edf6dd82e9662b72c17483de4de5575dd5acd972 commit edf6dd82e9662b72c17483de4de5575dd5acd972 Author: Mateusz Guzik AuthorDate: 2021-11-01 13:02:43 +0000 Commit: Mateusz Guzik CommitDate: 2021-11-01 19:59:05 +0000 pf: fix use-after-free from pf_find_state_all state was returned without any locks nor references held Reviewed by: kp Sponsored by: Rubicon Communications, LLC ("Netgate") --- sys/netpfil/pf/pf.c | 21 +++++++++++++++++++-- sys/netpfil/pf/pf_ioctl.c | 42 +++++++++++++++++++++++------------------- 2 files changed, 42 insertions(+), 21 deletions(-) diff --git a/sys/netpfil/pf/pf.c b/sys/netpfil/pf/pf.c index 61eea329a7f7..d7644b47f700 100644 --- a/sys/netpfil/pf/pf.c +++ b/sys/netpfil/pf/pf.c @@ -1510,6 +1510,9 @@ pf_find_state(struct pfi_kkif *kif, struct pf_state_key_cmp *key, u_int dir) return (NULL); } +/* + * Returns with ID hash slot locked on success. + */ struct pf_kstate * pf_find_state_all(struct pf_state_key_cmp *key, u_int dir, int *more) { @@ -1547,14 +1550,17 @@ pf_find_state_all(struct pf_state_key_cmp *key, u_int dir, int *more) second_run: TAILQ_FOREACH(s, &sk->states[idx], key_list[idx]) { if (more == NULL) { + PF_STATE_LOCK(s); PF_HASHROW_UNLOCK(kh); return (s); } if (ret) (*more)++; - else + else { ret = s; + PF_STATE_LOCK(s); + } } if (inout == 1) { inout = 0; @@ -1566,13 +1572,24 @@ second_run: return (ret); } +/* + * FIXME + * This routine is inefficient -- locks the state only to unlock immediately on + * return. + * It is racy -- after the state is unlocked nothing stops other threads from + * removing it. + */ bool pf_find_state_all_exists(struct pf_state_key_cmp *key, u_int dir) { struct pf_kstate *s; s = pf_find_state_all(key, dir, NULL); - return (s != NULL); + if (s != NULL) { + PF_STATE_UNLOCK(s); + return (true); + } + return (false); } /* END state table stuff */ diff --git a/sys/netpfil/pf/pf_ioctl.c b/sys/netpfil/pf/pf_ioctl.c index ee265de65b45..1cfedf19e662 100644 --- a/sys/netpfil/pf/pf_ioctl.c +++ b/sys/netpfil/pf/pf_ioctl.c @@ -2029,19 +2029,20 @@ pf_label_match(const struct pf_krule *rule, const char *label) static unsigned int pf_kill_matching_state(struct pf_state_key_cmp *key, int dir) { - struct pf_kstate *match; + struct pf_kstate *s; int more = 0; - unsigned int killed = 0; - /* Call with unlocked hashrow */ + s = pf_find_state_all(key, dir, &more); + if (s == NULL) + return (0); - match = pf_find_state_all(key, dir, &more); - if (match && !more) { - pf_unlink_state(match, 0); - killed++; + if (more) { + PF_STATE_UNLOCK(s); + return (0); } - return (killed); + pf_unlink_state(s, PF_ENTER_LOCKED); + return (1); } static int @@ -3159,18 +3160,21 @@ DIOCGETSTATESV2_full: key.port[didx] = pnl->dport; state = pf_find_state_all(&key, direction, &m); - - if (m > 1) - error = E2BIG; /* more than one state */ - else if (state != NULL) { - /* XXXGL: not locked read */ - sk = state->key[sidx]; - PF_ACPY(&pnl->rsaddr, &sk->addr[sidx], sk->af); - pnl->rsport = sk->port[sidx]; - PF_ACPY(&pnl->rdaddr, &sk->addr[didx], sk->af); - pnl->rdport = sk->port[didx]; - } else + if (state == NULL) { error = ENOENT; + } else { + if (m > 1) { + PF_STATE_UNLOCK(state); + error = E2BIG; /* more than one state */ + } else { + sk = state->key[sidx]; + PF_ACPY(&pnl->rsaddr, &sk->addr[sidx], sk->af); + pnl->rsport = sk->port[sidx]; + PF_ACPY(&pnl->rdaddr, &sk->addr[didx], sk->af); + pnl->rdport = sk->port[didx]; + PF_STATE_UNLOCK(state); + } + } } break; }