From nobody Thu Apr 07 13:14:34 2022 X-Original-To: dev-commits-src-branches@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 69E4C1A8176E; Thu, 7 Apr 2022 13:14:34 +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 4KZ20V2PgWz3rGC; Thu, 7 Apr 2022 13:14:34 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1649337274; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=ZGqZ1J7bDVejmc+ZxvEtksGlSP3biVQ0NrE6vTpGM+s=; b=Tdrvy8TC/7gaNuPVOAeNno7ePWF/RPXG9IookdLns6zBc1Ll7fq/tUOkww5nLHr8A1U6Ir txniPed0Jl8rui8h3O35pWZj7EHZSfqQdfedskf6zDF7onS2vOl7kBG59fb/eVx2FG/y9Y oU0OVEodfcgTQBWOnfqgqF22D309aGY+qXwYsRPoSm/Eg2npjaATY+j693wgrRZQn0/uxC Sr74lIrTA7Ti9e2Y8pGk41kKuKzD90I6lqsKtCHRKyzlp9A0hBpH6802//GSxYAEFK5eSm DvVw5itCe9YxliF9QBeFwntbsWU2mwMrkieJ33DEX1fLGVqC+haRfOirmyRb/w== 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 32EBF10E07; Thu, 7 Apr 2022 13:14:34 +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 237DEYCJ004553; Thu, 7 Apr 2022 13:14:34 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 237DEYYI004552; Thu, 7 Apr 2022 13:14:34 GMT (envelope-from git) Date: Thu, 7 Apr 2022 13:14:34 GMT Message-Id: <202204071314.237DEYYI004552@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Kristof Provost Subject: git: f4b8dad0cca4 - stable/12 - Address issue pointed out in CVE-2020-25705 List-Id: Commits to the stable branches of the FreeBSD src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-branches List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-dev-commits-src-branches@freebsd.org X-BeenThere: dev-commits-src-branches@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: kp X-Git-Repository: src X-Git-Refname: refs/heads/stable/12 X-Git-Reftype: branch X-Git-Commit: f4b8dad0cca474a0e830d1995d3d8d650530486b Auto-Submitted: auto-generated ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1649337274; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=ZGqZ1J7bDVejmc+ZxvEtksGlSP3biVQ0NrE6vTpGM+s=; b=dxaFFPLmGqml0F6qflhbD3sV3jitq9KhEiU2rPVGC8YnmojG7KYIKQSZNnFqGuVoDoLD3e uuxm4A2W5CToP3aBvaxXzPHNStl9kWjgsGrMBR1nRRgtTP4SwH82sqmfT+k1U1ArCvLWJs uGm0Q1117QERR72Fs2iw6S+Cad+7ACFbDbJvaGe0aHaDVkXTJwSQwnSXOx1SM1IWvwsanU RgGu0fC90ERFvJCCIeE2yNWptNcz07POVNZbccS9T4VTfIlQ4ZKrWFwCL1hWK7suxdTu3L Zz7WB3g7bLt+epBZKw2cHE7iV/OQV7tpCKw+U6TqEC10nLZNtHuhgJ3Mt1grDw== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1649337274; a=rsa-sha256; cv=none; b=spOYhc2vgsdWNtVST48Q559EE5cSA9DyjbOqFqlPhr4OSaZX1YYcJYnNJdQQQR85sE5maH H+YEz3HAt8flSFdppFUvuOE55ZySg6zNOPoFpLM92Oo1wOoqcTnSm1hFgnmkOHhLi0weTE O08riljpxJpvA4/g6UNJAqa5zZYgmk/V9LurA5+FhDHz7uRdwnZsQGGHJsNDaWBonSb7Ss cste60IU2t1pYTO3ltwQ1CWeIRHoi1k4b+QmNigUxGN6u8xf+cKV1s/lmh7wbhBxH1mbhz UDqs+8wl5SUC1vz5gG6E0IpKAzSO7ZXYW6lVQ8bnHTgalcDJY9nYOEpkyrIbgw== ARC-Authentication-Results: i=1; mx1.freebsd.org; none X-ThisMailContainsUnwantedMimeParts: N The branch stable/12 has been updated by kp: URL: https://cgit.FreeBSD.org/src/commit/?id=f4b8dad0cca474a0e830d1995d3d8d650530486b commit f4b8dad0cca474a0e830d1995d3d8d650530486b Author: George V. Neville-Neil AuthorDate: 2022-03-19 16:48:16 +0000 Commit: Kristof Provost CommitDate: 2022-04-07 07:32:11 +0000 Address issue pointed out in CVE-2020-25705 Add jitter to the ICMP bandwidth limit to deny a side-channel port scan. Reviewed by: kp, philip, cy, emaste MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D27354 (cherry picked from commit ca4cd20c4afeb68ae30c4cc1103280590a099fe7) --- sys/netinet/ip_icmp.c | 30 ++++++++++++++++++++++++++++-- 1 file changed, 28 insertions(+), 2 deletions(-) diff --git a/sys/netinet/ip_icmp.c b/sys/netinet/ip_icmp.c index 3c1f75753a51..f3abd3601b02 100644 --- a/sys/netinet/ip_icmp.c +++ b/sys/netinet/ip_icmp.c @@ -88,6 +88,14 @@ SYSCTL_INT(_net_inet_icmp, ICMPCTL_ICMPLIM, icmplim, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmplim), 0, "Maximum number of ICMP responses per second"); +VNET_DEFINE_STATIC(int, icmplim_curr_jitter) = 0; +#define V_icmplim_curr_jitter VNET(icmplim_curr_jitter) +VNET_DEFINE_STATIC(int, icmplim_jitter) = 16; +#define V_icmplim_jitter VNET(icmplim_jitter) +SYSCTL_INT(_net_inet_icmp, OID_AUTO, icmplim_jitter, CTLFLAG_VNET | CTLFLAG_RW, + &VNET_NAME(icmplim_jitter), 0, + "Random icmplim jitter adjustment limit"); + VNET_DEFINE_STATIC(int, icmplim_output) = 1; #define V_icmplim_output VNET(icmplim_output) SYSCTL_INT(_net_inet_icmp, OID_AUTO, icmplim_output, CTLFLAG_VNET | CTLFLAG_RW, @@ -1058,11 +1066,29 @@ badport_bandlim(int which) KASSERT(which >= 0 && which < BANDLIM_MAX, ("%s: which %d", __func__, which)); - pps = counter_ratecheck(&V_icmp_rates[which].cr, V_icmplim); + if ((V_icmplim + V_icmplim_curr_jitter) <= 0) + V_icmplim_curr_jitter = -V_icmplim + 1; + + pps = counter_ratecheck(&V_icmp_rates[which].cr, V_icmplim + + V_icmplim_curr_jitter); + if (pps > 0) { + /* + * Adjust limit +/- to jitter the measurement to deny a + * side-channel port scan as in CVE-2020-25705 + */ + if (V_icmplim_jitter > 0) { + int32_t inc = + arc4random_uniform(V_icmplim_jitter * 2 +1) + - V_icmplim_jitter; + + V_icmplim_curr_jitter = inc; + } + } if (pps == -1) return (-1); if (pps > 0 && V_icmplim_output) log(LOG_NOTICE, "Limiting %s from %jd to %d packets/sec\n", - V_icmp_rates[which].descr, (intmax_t )pps, V_icmplim); + V_icmp_rates[which].descr, (intmax_t )pps, V_icmplim + + V_icmplim_curr_jitter); return (0); }