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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 5F069C432C0 for ; Wed, 20 Nov 2019 15:43:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3ED0E20714 for ; Wed, 20 Nov 2019 15:43:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730556AbfKTPnZ (ORCPT ); Wed, 20 Nov 2019 10:43:25 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:52830 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730048AbfKTPkT (ORCPT ); Wed, 20 Nov 2019 10:40:19 -0500 Received: from [167.98.27.226] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iXS5U-0004b5-PJ; Wed, 20 Nov 2019 15:40:12 +0000 Received: from ben by deadeye with local (Exim 4.93-RC1) (envelope-from ) id 1iXS5U-0004J3-4q; Wed, 20 Nov 2019 15:40:12 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Zhang Tao" , "Mike Snitzer" , "Mikulas Patocka" Date: Wed, 20 Nov 2019 15:37:55 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 45/83] dm table: fix invalid memory accesses with too high sector number In-Reply-To: X-SA-Exim-Connect-IP: 167.98.27.226 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.78-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Mikulas Patocka commit 1cfd5d3399e87167b7f9157ef99daa0e959f395d upstream. If the sector number is too high, dm_table_find_target() should return a pointer to a zeroed dm_target structure (the caller should test it with dm_target_is_valid). However, for some table sizes, the code in dm_table_find_target() that performs btree lookup will access out of bound memory structures. Fix this bug by testing the sector number at the beginning of dm_table_find_target(). Also, add an "inline" keyword to the function dm_table_get_size() because this is a hot path. Fixes: 512875bd9661 ("dm: table detect io beyond device") Reported-by: Zhang Tao Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Ben Hutchings --- drivers/md/dm-table.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -1158,7 +1158,7 @@ void dm_table_event(struct dm_table *t) } EXPORT_SYMBOL(dm_table_event); -sector_t dm_table_get_size(struct dm_table *t) +inline sector_t dm_table_get_size(struct dm_table *t) { return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0; } @@ -1183,6 +1183,9 @@ struct dm_target *dm_table_find_target(s unsigned int l, n = 0, k = 0; sector_t *node; + if (unlikely(sector >= dm_table_get_size(t))) + return &t->targets[t->num_targets]; + for (l = 0; l < t->depth; l++) { n = get_child(n, k); node = get_node(t, l, n);