From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9F6CFC636CC for ; Sat, 18 Feb 2023 11:13:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229596AbjBRLNF (ORCPT ); Sat, 18 Feb 2023 06:13:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52112 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229613AbjBRLNF (ORCPT ); Sat, 18 Feb 2023 06:13:05 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8E33A1A940 for ; Sat, 18 Feb 2023 03:13:02 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 49EAAB822A4 for ; Sat, 18 Feb 2023 11:13:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id ADFF2C433EF; Sat, 18 Feb 2023 11:12:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1676718780; bh=SnGQxaMPEKmEwHYMa31zfvxuKqjbV5KIDmGTKzAAOfc=; h=Subject:To:Cc:From:Date:From; b=GHJWjQziTZbriuSJRRW4JjJ8cwgNzLyn5cs00ysxdm4fFVLlpUUbUPwGHrVKNZnkL mFc7FC/mGRpeyRuxMf9yvx39FdpV1qQvAqm38xgjyYC8yapJ4E4HL10wHldPX4OpoX 7cHaDs5JAg0FICApkFfmOqb3k6ayIyNiCVHFuYdI= Subject: FAILED: patch "[PATCH] net/sched: tcindex: update imperfect hash filters respecting" failed to apply to 5.4-stable tree To: pctammela@mojatatu.com, jhs@mojatatu.com, kuba@kernel.org, sec@valis.email Cc: From: Date: Sat, 18 Feb 2023 12:12:17 +0100 Message-ID: <16767187371266@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . Possible dependencies: ee059170b1f7 ("net/sched: tcindex: update imperfect hash filters respecting rcu") 304e024216a8 ("net_sched: add a temporary refcnt for struct tcindex_data") 599be01ee567 ("net_sched: fix an OOB access in cls_tcindex") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From ee059170b1f7e94e55fa6cadee544e176a6e59c2 Mon Sep 17 00:00:00 2001 From: Pedro Tammela Date: Thu, 9 Feb 2023 11:37:39 -0300 Subject: [PATCH] net/sched: tcindex: update imperfect hash filters respecting rcu The imperfect hash area can be updated while packets are traversing, which will cause a use-after-free when 'tcf_exts_exec()' is called with the destroyed tcf_ext. CPU 0: CPU 1: tcindex_set_parms tcindex_classify tcindex_lookup tcindex_lookup tcf_exts_change tcf_exts_exec [UAF] Stop operating on the shared area directly, by using a local copy, and update the filter with 'rcu_replace_pointer()'. Delete the old filter version only after a rcu grace period elapsed. Fixes: 9b0d4446b569 ("net: sched: avoid atomic swap in tcf_exts_change") Reported-by: valis Suggested-by: valis Signed-off-by: Jamal Hadi Salim Signed-off-by: Pedro Tammela Link: https://lore.kernel.org/r/20230209143739.279867-1-pctammela@mojatatu.com Signed-off-by: Jakub Kicinski diff --git a/net/sched/cls_tcindex.c b/net/sched/cls_tcindex.c index ee2a050c887b..ba7f22a49397 100644 --- a/net/sched/cls_tcindex.c +++ b/net/sched/cls_tcindex.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -339,6 +340,7 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base, struct tcf_result cr = {}; int err, balloc = 0; struct tcf_exts e; + bool update_h = false; err = tcf_exts_init(&e, net, TCA_TCINDEX_ACT, TCA_TCINDEX_POLICE); if (err < 0) @@ -456,10 +458,13 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base, } } - if (cp->perfect) + if (cp->perfect) { r = cp->perfect + handle; - else - r = tcindex_lookup(cp, handle) ? : &new_filter_result; + } else { + /* imperfect area is updated in-place using rcu */ + update_h = !!tcindex_lookup(cp, handle); + r = &new_filter_result; + } if (r == &new_filter_result) { f = kzalloc(sizeof(*f), GFP_KERNEL); @@ -485,7 +490,28 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base, rcu_assign_pointer(tp->root, cp); - if (r == &new_filter_result) { + if (update_h) { + struct tcindex_filter __rcu **fp; + struct tcindex_filter *cf; + + f->result.res = r->res; + tcf_exts_change(&f->result.exts, &r->exts); + + /* imperfect area bucket */ + fp = cp->h + (handle % cp->hash); + + /* lookup the filter, guaranteed to exist */ + for (cf = rcu_dereference_bh_rtnl(*fp); cf; + fp = &cf->next, cf = rcu_dereference_bh_rtnl(*fp)) + if (cf->key == handle) + break; + + f->next = cf->next; + + cf = rcu_replace_pointer(*fp, f, 1); + tcf_exts_get_net(&cf->result.exts); + tcf_queue_work(&cf->rwork, tcindex_destroy_fexts_work); + } else if (r == &new_filter_result) { struct tcindex_filter *nfp; struct tcindex_filter __rcu **fp;