From patchwork Sat Jan 29 01:59:22 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 12729352 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 933A4C433F5 for ; Sat, 29 Jan 2022 01:48:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344830AbiA2Bsn (ORCPT ); Fri, 28 Jan 2022 20:48:43 -0500 Received: from szxga01-in.huawei.com ([45.249.212.187]:16933 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352085AbiA2Bsm (ORCPT ); Fri, 28 Jan 2022 20:48:42 -0500 Received: from kwepemi100006.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4Jlxvt0DPyzZfQF; Sat, 29 Jan 2022 09:44:42 +0800 (CST) Received: from kwepemm600009.china.huawei.com (7.193.23.164) by kwepemi100006.china.huawei.com (7.221.188.165) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Sat, 29 Jan 2022 09:48:39 +0800 Received: from huawei.com (10.175.127.227) by kwepemm600009.china.huawei.com (7.193.23.164) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Sat, 29 Jan 2022 09:48:39 +0800 From: Yu Kuai To: , , CC: , , , , Subject: [PATCH v3 1/3] block, bfq: cleanup bfq_bfqq_to_bfqg() Date: Sat, 29 Jan 2022 09:59:22 +0800 Message-ID: <20220129015924.3958918-2-yukuai3@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20220129015924.3958918-1-yukuai3@huawei.com> References: <20220129015924.3958918-1-yukuai3@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To kwepemm600009.china.huawei.com (7.193.23.164) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Use bfq_group() instead, which do the same thing. Signed-off-by: Yu Kuai Reviewed-by: Jan Kara Acked-by: Paolo Valente --- block/bfq-iosched.c | 4 ++-- block/bfq-iosched.h | 1 - block/bfq-wf2q.c | 15 --------------- 3 files changed, 2 insertions(+), 18 deletions(-) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 0c612a911696..2f2b97cad980 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -774,7 +774,7 @@ bfq_pos_tree_add_move(struct bfq_data *bfqd, struct bfq_queue *bfqq) if (!bfqq->next_rq) return; - bfqq->pos_root = &bfq_bfqq_to_bfqg(bfqq)->rq_pos_tree; + bfqq->pos_root = &bfqq_group(bfqq)->rq_pos_tree; __bfqq = bfq_rq_pos_tree_lookup(bfqd, bfqq->pos_root, blk_rq_pos(bfqq->next_rq), &parent, &p); if (!__bfqq) { @@ -2669,7 +2669,7 @@ static struct bfq_queue *bfqq_find_close(struct bfq_data *bfqd, struct bfq_queue *bfqq, sector_t sector) { - struct rb_root *root = &bfq_bfqq_to_bfqg(bfqq)->rq_pos_tree; + struct rb_root *root = &bfqq_group(bfqq)->rq_pos_tree; struct rb_node *parent, *node; struct bfq_queue *__bfqq; diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h index 07288b9da389..99949548896e 100644 --- a/block/bfq-iosched.h +++ b/block/bfq-iosched.h @@ -1051,7 +1051,6 @@ extern struct blkcg_policy blkcg_policy_bfq; for (parent = NULL; entity ; entity = parent) #endif /* CONFIG_BFQ_GROUP_IOSCHED */ -struct bfq_group *bfq_bfqq_to_bfqg(struct bfq_queue *bfqq); struct bfq_queue *bfq_entity_to_bfqq(struct bfq_entity *entity); unsigned int bfq_tot_busy_queues(struct bfq_data *bfqd); struct bfq_service_tree *bfq_entity_service_tree(struct bfq_entity *entity); diff --git a/block/bfq-wf2q.c b/block/bfq-wf2q.c index b74cc0da118e..e1f5ca5c1fdb 100644 --- a/block/bfq-wf2q.c +++ b/block/bfq-wf2q.c @@ -142,16 +142,6 @@ static bool bfq_update_next_in_service(struct bfq_sched_data *sd, #ifdef CONFIG_BFQ_GROUP_IOSCHED -struct bfq_group *bfq_bfqq_to_bfqg(struct bfq_queue *bfqq) -{ - struct bfq_entity *group_entity = bfqq->entity.parent; - - if (!group_entity) - group_entity = &bfqq->bfqd->root_group->entity; - - return container_of(group_entity, struct bfq_group, entity); -} - /* * Returns true if this budget changes may let next_in_service->parent * become the next_in_service entity for its parent entity. @@ -230,11 +220,6 @@ static bool bfq_no_longer_next_in_service(struct bfq_entity *entity) #else /* CONFIG_BFQ_GROUP_IOSCHED */ -struct bfq_group *bfq_bfqq_to_bfqg(struct bfq_queue *bfqq) -{ - return bfqq->bfqd->root_group; -} - static bool bfq_update_parent_budget(struct bfq_entity *next_in_service) { return false; From patchwork Sat Jan 29 01:59:23 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 12729353 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 B5DEFC433FE for ; Sat, 29 Jan 2022 01:48:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352102AbiA2Bsp (ORCPT ); Fri, 28 Jan 2022 20:48:45 -0500 Received: from szxga03-in.huawei.com ([45.249.212.189]:32131 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352083AbiA2Bsm (ORCPT ); Fri, 28 Jan 2022 20:48:42 -0500 Received: from kwepemi500016.china.huawei.com (unknown [172.30.72.54]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4Jlxx05GsFz8wWB; Sat, 29 Jan 2022 09:45:40 +0800 (CST) Received: from kwepemm600009.china.huawei.com (7.193.23.164) by kwepemi500016.china.huawei.com (7.221.188.220) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Sat, 29 Jan 2022 09:48:40 +0800 Received: from huawei.com (10.175.127.227) by kwepemm600009.china.huawei.com (7.193.23.164) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Sat, 29 Jan 2022 09:48:39 +0800 From: Yu Kuai To: , , CC: , , , , Subject: [PATCH v3 2/3] block, bfq: avoid moving bfqq to it's parent bfqg Date: Sat, 29 Jan 2022 09:59:23 +0800 Message-ID: <20220129015924.3958918-3-yukuai3@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20220129015924.3958918-1-yukuai3@huawei.com> References: <20220129015924.3958918-1-yukuai3@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To kwepemm600009.china.huawei.com (7.193.23.164) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Moving bfqq to it's parent bfqg is pointless. Signed-off-by: Yu Kuai --- block/bfq-cgroup.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c index 24a5c5329bcd..9783c1156159 100644 --- a/block/bfq-cgroup.c +++ b/block/bfq-cgroup.c @@ -645,6 +645,14 @@ void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq, struct bfq_group *bfqg) { struct bfq_entity *entity = &bfqq->entity; + struct bfq_group *old_parent = bfqq_group(bfqq); + + /* + * No point to move bfqq to the same group, which can happen when + * root group is offlined + */ + if (old_parent == bfqg) + return; /* * Get extra reference to prevent bfqq from being freed in @@ -666,7 +674,7 @@ void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq, bfq_deactivate_bfqq(bfqd, bfqq, false, false); else if (entity->on_st_or_in_serv) bfq_put_idle_entity(bfq_entity_service_tree(entity), entity); - bfqg_and_blkg_put(bfqq_group(bfqq)); + bfqg_and_blkg_put(old_parent); if (entity->parent && entity->parent->last_bfqq_created == bfqq) From patchwork Sat Jan 29 01:59:24 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 12729354 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 DD45BC433F5 for ; Sat, 29 Jan 2022 01:48:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352106AbiA2Bsp (ORCPT ); Fri, 28 Jan 2022 20:48:45 -0500 Received: from szxga02-in.huawei.com ([45.249.212.188]:31253 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352092AbiA2Bsn (ORCPT ); Fri, 28 Jan 2022 20:48:43 -0500 Received: from kwepemi500015.china.huawei.com (unknown [172.30.72.55]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4JlxzT0lpkzbkCP; Sat, 29 Jan 2022 09:47:49 +0800 (CST) Received: from kwepemm600009.china.huawei.com (7.193.23.164) by kwepemi500015.china.huawei.com (7.221.188.92) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Sat, 29 Jan 2022 09:48:41 +0800 Received: from huawei.com (10.175.127.227) by kwepemm600009.china.huawei.com (7.193.23.164) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Sat, 29 Jan 2022 09:48:40 +0800 From: Yu Kuai To: , , CC: , , , , Subject: [PATCH v3 3/3] block, bfq: don't move oom_bfqq Date: Sat, 29 Jan 2022 09:59:24 +0800 Message-ID: <20220129015924.3958918-4-yukuai3@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20220129015924.3958918-1-yukuai3@huawei.com> References: <20220129015924.3958918-1-yukuai3@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To kwepemm600009.china.huawei.com (7.193.23.164) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Our test report a UAF: [ 2073.019181] ================================================================== [ 2073.019188] BUG: KASAN: use-after-free in __bfq_put_async_bfqq+0xa0/0x168 [ 2073.019191] Write of size 8 at addr ffff8000ccf64128 by task rmmod/72584 [ 2073.019192] [ 2073.019196] CPU: 0 PID: 72584 Comm: rmmod Kdump: loaded Not tainted 4.19.90-yk #5 [ 2073.019198] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015 [ 2073.019200] Call trace: [ 2073.019203] dump_backtrace+0x0/0x310 [ 2073.019206] show_stack+0x28/0x38 [ 2073.019210] dump_stack+0xec/0x15c [ 2073.019216] print_address_description+0x68/0x2d0 [ 2073.019220] kasan_report+0x238/0x2f0 [ 2073.019224] __asan_store8+0x88/0xb0 [ 2073.019229] __bfq_put_async_bfqq+0xa0/0x168 [ 2073.019233] bfq_put_async_queues+0xbc/0x208 [ 2073.019236] bfq_pd_offline+0x178/0x238 [ 2073.019240] blkcg_deactivate_policy+0x1f0/0x420 [ 2073.019244] bfq_exit_queue+0x128/0x178 [ 2073.019249] blk_mq_exit_sched+0x12c/0x160 [ 2073.019252] elevator_exit+0xc8/0xd0 [ 2073.019256] blk_exit_queue+0x50/0x88 [ 2073.019259] blk_cleanup_queue+0x228/0x3d8 [ 2073.019267] null_del_dev+0xfc/0x1e0 [null_blk] [ 2073.019274] null_exit+0x90/0x114 [null_blk] [ 2073.019278] __arm64_sys_delete_module+0x358/0x5a0 [ 2073.019282] el0_svc_common+0xc8/0x320 [ 2073.019287] el0_svc_handler+0xf8/0x160 [ 2073.019290] el0_svc+0x10/0x218 [ 2073.019291] [ 2073.019294] Allocated by task 14163: [ 2073.019301] kasan_kmalloc+0xe0/0x190 [ 2073.019305] kmem_cache_alloc_node_trace+0x1cc/0x418 [ 2073.019308] bfq_pd_alloc+0x54/0x118 [ 2073.019313] blkcg_activate_policy+0x250/0x460 [ 2073.019317] bfq_create_group_hierarchy+0x38/0x110 [ 2073.019321] bfq_init_queue+0x6d0/0x948 [ 2073.019325] blk_mq_init_sched+0x1d8/0x390 [ 2073.019330] elevator_switch_mq+0x88/0x170 [ 2073.019334] elevator_switch+0x140/0x270 [ 2073.019338] elv_iosched_store+0x1a4/0x2a0 [ 2073.019342] queue_attr_store+0x90/0xe0 [ 2073.019348] sysfs_kf_write+0xa8/0xe8 [ 2073.019351] kernfs_fop_write+0x1f8/0x378 [ 2073.019359] __vfs_write+0xe0/0x360 [ 2073.019363] vfs_write+0xf0/0x270 [ 2073.019367] ksys_write+0xdc/0x1b8 [ 2073.019371] __arm64_sys_write+0x50/0x60 [ 2073.019375] el0_svc_common+0xc8/0x320 [ 2073.019380] el0_svc_handler+0xf8/0x160 [ 2073.019383] el0_svc+0x10/0x218 [ 2073.019385] [ 2073.019387] Freed by task 72584: [ 2073.019391] __kasan_slab_free+0x120/0x228 [ 2073.019394] kasan_slab_free+0x10/0x18 [ 2073.019397] kfree+0x94/0x368 [ 2073.019400] bfqg_put+0x64/0xb0 [ 2073.019404] bfqg_and_blkg_put+0x90/0xb0 [ 2073.019408] bfq_put_queue+0x220/0x228 [ 2073.019413] __bfq_put_async_bfqq+0x98/0x168 [ 2073.019416] bfq_put_async_queues+0xbc/0x208 [ 2073.019420] bfq_pd_offline+0x178/0x238 [ 2073.019424] blkcg_deactivate_policy+0x1f0/0x420 [ 2073.019429] bfq_exit_queue+0x128/0x178 [ 2073.019433] blk_mq_exit_sched+0x12c/0x160 [ 2073.019437] elevator_exit+0xc8/0xd0 [ 2073.019440] blk_exit_queue+0x50/0x88 [ 2073.019443] blk_cleanup_queue+0x228/0x3d8 [ 2073.019451] null_del_dev+0xfc/0x1e0 [null_blk] [ 2073.019459] null_exit+0x90/0x114 [null_blk] [ 2073.019462] __arm64_sys_delete_module+0x358/0x5a0 [ 2073.019467] el0_svc_common+0xc8/0x320 [ 2073.019471] el0_svc_handler+0xf8/0x160 [ 2073.019474] el0_svc+0x10/0x218 [ 2073.019475] [ 2073.019479] The buggy address belongs to the object at ffff8000ccf63f00 which belongs to the cache kmalloc-1024 of size 1024 [ 2073.019484] The buggy address is located 552 bytes inside of 1024-byte region [ffff8000ccf63f00, ffff8000ccf64300) [ 2073.019486] The buggy address belongs to the page: [ 2073.019492] page:ffff7e000333d800 count:1 mapcount:0 mapping:ffff8000c0003a00 index:0x0 compound_mapcount: 0 [ 2073.020123] flags: 0x7ffff0000008100(slab|head) [ 2073.020403] raw: 07ffff0000008100 ffff7e0003334c08 ffff7e00001f5a08 ffff8000c0003a00 [ 2073.020409] raw: 0000000000000000 00000000001c001c 00000001ffffffff 0000000000000000 [ 2073.020411] page dumped because: kasan: bad access detected [ 2073.020412] [ 2073.020414] Memory state around the buggy address: [ 2073.020420] ffff8000ccf64000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 2073.020424] ffff8000ccf64080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 2073.020428] >ffff8000ccf64100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 2073.020430] ^ [ 2073.020434] ffff8000ccf64180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 2073.020438] ffff8000ccf64200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 2073.020439] ================================================================== The same problem exist in mainline as well. This is because oom_bfqq is moved to a non-root group, thus root_group is freed earlier. Thus fix the problem by don't move oom_bfqq. Signed-off-by: Yu Kuai Reviewed-by: Jan Kara Acked-by: Paolo Valente --- block/bfq-cgroup.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c index 9783c1156159..420eda2589c0 100644 --- a/block/bfq-cgroup.c +++ b/block/bfq-cgroup.c @@ -654,6 +654,12 @@ void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq, if (old_parent == bfqg) return; + /* + * oom_bfqq is not allowed to move, oom_bfqq will hold ref to root_group + * until elevator exit. + */ + if (bfqq == &bfqd->oom_bfqq) + return; /* * Get extra reference to prevent bfqq from being freed in * next possible expire or deactivate.