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=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 AFC83C433E0 for ; Sun, 12 Jul 2020 17:47:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 98AE22063A for ; Sun, 12 Jul 2020 17:47:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729272AbgGLRry (ORCPT ); Sun, 12 Jul 2020 13:47:54 -0400 Received: from mx2.suse.de ([195.135.220.15]:38550 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728882AbgGLRrx (ORCPT ); Sun, 12 Jul 2020 13:47:53 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id D6E64AD4B; Sun, 12 Jul 2020 17:47:53 +0000 (UTC) From: Coly Li To: linux-bcache@vger.kernel.org Cc: linux-block@vger.kernel.org, Coly Li , Ken Raeburn , stable@vger.kernel.org Subject: [PATCH 2/2] bcche: fix overflow in offset_to_stripe() Date: Mon, 13 Jul 2020 01:47:36 +0800 Message-Id: <20200712174736.9840-2-colyli@suse.de> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200712174736.9840-1-colyli@suse.de> References: <20200712174736.9840-1-colyli@suse.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org offset_to_stripe() returns the stripe number (in type unsigned int) from an offset (in type uint64_t) by the following calculation, do_div(offset, d->stripe_size); For large capacity backing device (e.g. 18TB) with small stripe size (e.g. 4KB), the result is 4831838208 and exceeds UINT_MAX. The actual returned value which caller receives is 536870912, due to the overflow. This patch changes offset_to_stripe()'s return value from type unsigned int to long int, and returns -EINVAL if do_div() result >= current max stripe number bcache_device->nr_stripes. Because nr_stripe is in type unsigned int, the non-negative return value will never overflow. Reported-by: Ken Raeburn Signed-off-by: Coly Li Link: https://bugzilla.redhat.com/show_bug.cgi?id=1783075 Cc: stable@vger.kernel.org --- drivers/md/bcache/writeback.c | 14 +++++++++----- drivers/md/bcache/writeback.h | 18 ++++++++++++++++-- 2 files changed, 25 insertions(+), 7 deletions(-) diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c index 5397a2c5d6cc..2de6e9260443 100644 --- a/drivers/md/bcache/writeback.c +++ b/drivers/md/bcache/writeback.c @@ -521,15 +521,19 @@ void bcache_dev_sectors_dirty_add(struct cache_set *c, unsigned int inode, uint64_t offset, int nr_sectors) { struct bcache_device *d = c->devices[inode]; - unsigned int stripe_offset, stripe, sectors_dirty; + unsigned int stripe_offset, sectors_dirty; + long stripe; if (!d) return; + stripe = offset_to_stripe(d, offset); + if (stripe < 0) + return; + if (UUID_FLASH_ONLY(&c->uuids[inode])) atomic_long_add(nr_sectors, &c->flash_dev_dirty_sectors); - stripe = offset_to_stripe(d, offset); stripe_offset = offset & (d->stripe_size - 1); while (nr_sectors) { @@ -569,12 +573,12 @@ static bool dirty_pred(struct keybuf *buf, struct bkey *k) static void refill_full_stripes(struct cached_dev *dc) { struct keybuf *buf = &dc->writeback_keys; - unsigned int start_stripe, stripe, next_stripe; + unsigned int start_stripe, next_stripe; + long stripe; bool wrapped = false; stripe = offset_to_stripe(&dc->disk, KEY_OFFSET(&buf->last_scanned)); - - if (stripe >= dc->disk.nr_stripes) + if (stripe < 0) stripe = 0; start_stripe = stripe; diff --git a/drivers/md/bcache/writeback.h b/drivers/md/bcache/writeback.h index b029843ce5b6..8550b984954a 100644 --- a/drivers/md/bcache/writeback.h +++ b/drivers/md/bcache/writeback.h @@ -52,10 +52,21 @@ static inline uint64_t bcache_dev_sectors_dirty(struct bcache_device *d) return ret; } -static inline unsigned int offset_to_stripe(struct bcache_device *d, +static inline long offset_to_stripe(struct bcache_device *d, uint64_t offset) { do_div(offset, d->stripe_size); + + if (unlikely(offset >= d->nr_stripes)) { + pr_err("Invalid stripe %llu (>= nr_stripes %u).\n", + offset, d->nr_stripes); + return -EINVAL; + } + + /* + * Here offset is definitly smaller than UINT_MAX, + * return it as long int will never overflow. + */ return offset; } @@ -63,7 +74,10 @@ static inline bool bcache_dev_stripe_dirty(struct cached_dev *dc, uint64_t offset, unsigned int nr_sectors) { - unsigned int stripe = offset_to_stripe(&dc->disk, offset); + long stripe = offset_to_stripe(&dc->disk, offset); + + if (stripe < 0) + return false; while (1) { if (atomic_read(dc->disk.stripe_sectors_dirty + stripe)) -- 2.26.2