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 4CB35EB64D9 for ; Wed, 28 Jun 2023 01:08:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229854AbjF1BI4 (ORCPT ); Tue, 27 Jun 2023 21:08:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41386 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229719AbjF1BIy (ORCPT ); Tue, 27 Jun 2023 21:08:54 -0400 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1638E1BD4; Tue, 27 Jun 2023 18:08:53 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4QrNkn4Xqfz4f3nTp; Wed, 28 Jun 2023 09:08:49 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP4 (Coremail) with SMTP id gCh0CgAHuKsfiJtk9u_GMg--.34640S6; Wed, 28 Jun 2023 09:08:50 +0800 (CST) From: Yu Kuai To: xni@redhat.com, logang@deltatee.com, hch@lst.de, song@kernel.org, shli@fb.com Cc: linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, yukuai3@huawei.com, yukuai1@huaweicloud.com, yi.zhang@huawei.com, yangerkun@huawwe.com Subject: [PATCH -next v2 2/2] md/raid5-cache: fix null-ptr-deref in r5l_reclaim_thread() Date: Wed, 28 Jun 2023 09:07:56 +0800 Message-Id: <20230628010756.70649-3-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230628010756.70649-1-yukuai1@huaweicloud.com> References: <20230628010756.70649-1-yukuai1@huaweicloud.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID: gCh0CgAHuKsfiJtk9u_GMg--.34640S6 X-Coremail-Antispam: 1UD129KBjvJXoWxAr4fuw1rtw1UXr4Uuw1ftFb_yoW5tw48pa 1Sg3y3Ww48urWfAFnrWr1Dur4F93sF934xG3y5Cwn2yr13Xry8Ja47CayUZFy5JFW8Ary3 XrZ8tF48WrnrtrJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBE14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_Jryl82xGYIkIc2 x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJw A2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq3wAS 0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2 IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0 Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2kIc2 xKxwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v2 6r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIxkGc2 Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_ Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMI IF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x0JUHbyAUUUUU = X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org From: Yu Kuai r5l_reclaim_thread() already check that 'conf->log' is not NULL in the beginning, however, r5c_do_reclaim() and r5l_do_reclaim() will dereference 'conf->log' again, which will cause null-ptr-deref if 'conf->log' is set to NULL from r5l_exit_log() concurrently. Fix this problem by don't dereference 'conf->log' again in r5c_do_reclaim() and r5c_do_reclaim(). Fixes: a39f7afde358 ("md/r5cache: write-out phase and reclaim support") Signed-off-by: Yu Kuai --- drivers/md/raid5-cache.c | 20 ++++++++------------ 1 file changed, 8 insertions(+), 12 deletions(-) diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c index 083288e36949..ba6fc146d265 100644 --- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -1148,10 +1148,9 @@ static void r5l_run_no_space_stripes(struct r5l_log *log) * for write through mode, returns log->next_checkpoint * for write back, returns log_start of first sh in stripe_in_journal_list */ -static sector_t r5c_calculate_new_cp(struct r5conf *conf) +static sector_t r5c_calculate_new_cp(struct r5l_log *log) { struct stripe_head *sh; - struct r5l_log *log = conf->log; sector_t new_cp; unsigned long flags; @@ -1159,12 +1158,12 @@ static sector_t r5c_calculate_new_cp(struct r5conf *conf) return log->next_checkpoint; spin_lock_irqsave(&log->stripe_in_journal_lock, flags); - if (list_empty(&conf->log->stripe_in_journal_list)) { + if (list_empty(&log->stripe_in_journal_list)) { /* all stripes flushed */ spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags); return log->next_checkpoint; } - sh = list_first_entry(&conf->log->stripe_in_journal_list, + sh = list_first_entry(&log->stripe_in_journal_list, struct stripe_head, r5c); new_cp = sh->log_start; spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags); @@ -1173,10 +1172,8 @@ static sector_t r5c_calculate_new_cp(struct r5conf *conf) static sector_t r5l_reclaimable_space(struct r5l_log *log) { - struct r5conf *conf = log->rdev->mddev->private; - return r5l_ring_distance(log, log->last_checkpoint, - r5c_calculate_new_cp(conf)); + r5c_calculate_new_cp(log)); } static void r5l_run_no_mem_stripe(struct r5l_log *log) @@ -1419,9 +1416,9 @@ void r5c_flush_cache(struct r5conf *conf, int num) } } -static void r5c_do_reclaim(struct r5conf *conf) +static void r5c_do_reclaim(struct r5l_log *log) { - struct r5l_log *log = conf->log; + struct r5conf *conf = log->rdev->mddev->private; struct stripe_head *sh; int count = 0; unsigned long flags; @@ -1496,7 +1493,6 @@ static void r5c_do_reclaim(struct r5conf *conf) static void r5l_do_reclaim(struct r5l_log *log) { - struct r5conf *conf = log->rdev->mddev->private; sector_t reclaim_target = xchg(&log->reclaim_target, 0); sector_t reclaimable; sector_t next_checkpoint; @@ -1525,7 +1521,7 @@ static void r5l_do_reclaim(struct r5l_log *log) log->io_list_lock); } - next_checkpoint = r5c_calculate_new_cp(conf); + next_checkpoint = r5c_calculate_new_cp(log); spin_unlock_irq(&log->io_list_lock); if (reclaimable == 0 || !write_super) @@ -1554,7 +1550,7 @@ static void r5l_reclaim_thread(struct md_thread *thread) if (!log) return; - r5c_do_reclaim(conf); + r5c_do_reclaim(log); r5l_do_reclaim(log); } -- 2.39.2