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 X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EE5FEC433E0 for ; Tue, 2 Feb 2021 15:10:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AEF9164E9E for ; Tue, 2 Feb 2021 15:10:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234971AbhBBPKW (ORCPT ); Tue, 2 Feb 2021 10:10:22 -0500 Received: from mail.kernel.org ([198.145.29.99]:34948 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235010AbhBBPG6 (ORCPT ); Tue, 2 Feb 2021 10:06:58 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0EBD660235; Tue, 2 Feb 2021 15:06:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1612278377; bh=TCV7KUcTSr1en8/CCzAjSD+7rg3xTxSgUfFS669nnVU=; h=From:To:Cc:Subject:Date:From; b=ei8sWPvglVblNEvu3XfhxWHpv27UZvMFr0tSIA9t6qD1Dy2EY/hYcmsxcWeYMqmZY yOuD7NIL1cZUsKu5j1gqQY5sYy3AyZ6K1OoSYQDcVPbpowYV6OHUwhOBXs+xTCs6ys 3mePl/R6oDf8V7XtPngtZcVJlagIyA6cnpmBaDJXKFrCazedbrCmF6Bo9Bwma0MMXK iNyGxavqbl50leZP+e3Nev2E803MvOG4Y0leFvBneUkpxs1cU1CwbVuewfCra6YHcM oqZwEwK8DQRkFJq0fcM8QahPWUpCHF+Op7FjE5mtoRaaPrs27S95Ab7AgIzA7c1xb8 yxBf5zXacLg/w== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Cong Wang , syzbot+b2bf2652983d23734c5c@syzkaller.appspotmail.com, Steffen Klassert , Herbert Xu , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.10 01/25] af_key: relax availability checks for skb size calculation Date: Tue, 2 Feb 2021 10:05:51 -0500 Message-Id: <20210202150615.1864175-1-sashal@kernel.org> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Cong Wang [ Upstream commit afbc293add6466f8f3f0c3d944d85f53709c170f ] xfrm_probe_algs() probes kernel crypto modules and changes the availability of struct xfrm_algo_desc. But there is a small window where ealg->available and aalg->available get changed between count_ah_combs()/count_esp_combs() and dump_ah_combs()/dump_esp_combs(), in this case we may allocate a smaller skb but later put a larger amount of data and trigger the panic in skb_put(). Fix this by relaxing the checks when counting the size, that is, skipping the test of ->available. We may waste some memory for a few of sizeof(struct sadb_comb), but it is still much better than a panic. Reported-by: syzbot+b2bf2652983d23734c5c@syzkaller.appspotmail.com Cc: Steffen Klassert Cc: Herbert Xu Signed-off-by: Cong Wang Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin --- net/key/af_key.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/key/af_key.c b/net/key/af_key.c index c12dbc51ef5fe..ef9b4ac03e7b7 100644 --- a/net/key/af_key.c +++ b/net/key/af_key.c @@ -2902,7 +2902,7 @@ static int count_ah_combs(const struct xfrm_tmpl *t) break; if (!aalg->pfkey_supported) continue; - if (aalg_tmpl_set(t, aalg) && aalg->available) + if (aalg_tmpl_set(t, aalg)) sz += sizeof(struct sadb_comb); } return sz + sizeof(struct sadb_prop); @@ -2920,7 +2920,7 @@ static int count_esp_combs(const struct xfrm_tmpl *t) if (!ealg->pfkey_supported) continue; - if (!(ealg_tmpl_set(t, ealg) && ealg->available)) + if (!(ealg_tmpl_set(t, ealg))) continue; for (k = 1; ; k++) { @@ -2931,7 +2931,7 @@ static int count_esp_combs(const struct xfrm_tmpl *t) if (!aalg->pfkey_supported) continue; - if (aalg_tmpl_set(t, aalg) && aalg->available) + if (aalg_tmpl_set(t, aalg)) sz += sizeof(struct sadb_comb); } } -- 2.27.0