From patchwork Thu Nov 24 14:06:34 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Li Nan X-Patchwork-Id: 13054990 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 711B2C433FE for ; Thu, 24 Nov 2022 13:45:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229726AbiKXNpe (ORCPT ); Thu, 24 Nov 2022 08:45:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36648 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230090AbiKXNp2 (ORCPT ); Thu, 24 Nov 2022 08:45:28 -0500 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8B336109581; Thu, 24 Nov 2022 05:45:23 -0800 (PST) Received: from dggpeml500025.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4NHzkm5pWJzmW6p; Thu, 24 Nov 2022 21:44:48 +0800 (CST) Received: from dggpeml500003.china.huawei.com (7.185.36.200) by dggpeml500025.china.huawei.com (7.185.36.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Thu, 24 Nov 2022 21:45:21 +0800 Received: from huawei.com (10.175.127.227) by dggpeml500003.china.huawei.com (7.185.36.200) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Thu, 24 Nov 2022 21:45:21 +0800 From: Li Nan To: , , CC: , , , , , Subject: [PATCH -next 1/2] blk-iocost: fix divide by 0 error in calc_lcoefs() Date: Thu, 24 Nov 2022 22:06:34 +0800 Message-ID: <20221124140635.695205-1-linan122@huawei.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpeml500003.china.huawei.com (7.185.36.200) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org echo max of u64 to cost.model can cause divide by 0 error. # echo 8:0 rbps=18446744073709551615 > /sys/fs/cgroup/io.cost.model divide error: 0000 [#1] PREEMPT SMP RIP: 0010:calc_lcoefs+0x4c/0xc0 Call Trace: ioc_refresh_params+0x2b3/0x4f0 ioc_cost_model_write+0x3cb/0x4c0 ? _copy_from_iter+0x6d/0x6c0 ? kernfs_fop_write_iter+0xfc/0x270 cgroup_file_write+0xa0/0x200 kernfs_fop_write_iter+0x17d/0x270 vfs_write+0x414/0x620 ksys_write+0x73/0x160 __x64_sys_write+0x1e/0x30 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd calc_lcoefs() uses the input value of cost.model in DIV_ROUND_UP_ULL, overflow would happen if bps plus IOC_PAGE_SIZE is greater than ULLONG_MAX, it can cause divide by 0 error.I_LCOEF_MAX is introduced to prevent it. Signed-off-by: Li Nan Reviewed-by: Andreas Herrmann --- block/blk-iocost.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index f01359906c83..a38a5324bf10 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -306,6 +306,9 @@ enum { IOC_PAGE_SIZE = 1 << IOC_PAGE_SHIFT, IOC_SECT_TO_PAGE_SHIFT = IOC_PAGE_SHIFT - SECTOR_SHIFT, + /* avoid overflow */ + I_LCOEF_MAX = ULLONG_MAX - IOC_PAGE_SIZE, + /* if apart further than 16M, consider randio for linear model */ LCOEF_RANDIO_PAGES = 4096, }; @@ -3406,6 +3409,8 @@ static ssize_t ioc_cost_model_write(struct kernfs_open_file *of, char *input, goto einval; if (match_u64(&args[0], &v)) goto einval; + if (v > I_LCOEF_MAX) + goto einval; u[tok] = v; user = true; } From patchwork Thu Nov 24 14:06:35 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Li Nan X-Patchwork-Id: 13054991 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 960DFC43217 for ; Thu, 24 Nov 2022 13:45:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229988AbiKXNpf (ORCPT ); Thu, 24 Nov 2022 08:45:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36680 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230094AbiKXNp3 (ORCPT ); Thu, 24 Nov 2022 08:45:29 -0500 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DE29A1095A0; Thu, 24 Nov 2022 05:45:23 -0800 (PST) Received: from dggpeml500020.china.huawei.com (unknown [172.30.72.56]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4NHzkh4cHKzHw1P; Thu, 24 Nov 2022 21:44:44 +0800 (CST) Received: from dggpeml500003.china.huawei.com (7.185.36.200) by dggpeml500020.china.huawei.com (7.185.36.88) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Thu, 24 Nov 2022 21:45:22 +0800 Received: from huawei.com (10.175.127.227) by dggpeml500003.china.huawei.com (7.185.36.200) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Thu, 24 Nov 2022 21:45:21 +0800 From: Li Nan To: , , CC: , , , , , Subject: [PATCH -next 2/2] blk-iocost: change div64_u64 to DIV64_U64_ROUND_UP in ioc_refresh_params() Date: Thu, 24 Nov 2022 22:06:35 +0800 Message-ID: <20221124140635.695205-2-linan122@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20221124140635.695205-1-linan122@huawei.com> References: <20221124140635.695205-1-linan122@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpeml500003.china.huawei.com (7.185.36.200) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org vrate_min is calculated by DIV64_U64_ROUND_UP, but vrate_max is calculated by div64_u64. Vrate_min may be 1 greater than vrate_max if the input values min and max of cost.qos are equal. Signed-off-by: Li Nan Reviewed-by: Andreas Herrmann --- block/blk-iocost.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index a38a5324bf10..9030ad8672f3 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -926,7 +926,7 @@ static bool ioc_refresh_params(struct ioc *ioc, bool force) ioc->vrate_min = DIV64_U64_ROUND_UP((u64)ioc->params.qos[QOS_MIN] * VTIME_PER_USEC, MILLION); - ioc->vrate_max = div64_u64((u64)ioc->params.qos[QOS_MAX] * + ioc->vrate_max = DIV64_U64_ROUND_UP((u64)ioc->params.qos[QOS_MAX] * VTIME_PER_USEC, MILLION); return true;