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=-8.7 required=3.0 tests=BAYES_00,FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 7623AC4361B for ; Fri, 18 Dec 2020 16:44:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 247FC23B28 for ; Fri, 18 Dec 2020 16:44:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729057AbgLRQoo (ORCPT ); Fri, 18 Dec 2020 11:44:44 -0500 Received: from mail-il1-f199.google.com ([209.85.166.199]:36387 "EHLO mail-il1-f199.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729090AbgLRQoo (ORCPT ); Fri, 18 Dec 2020 11:44:44 -0500 Received: by mail-il1-f199.google.com with SMTP id z15so2579007ilb.3 for ; Fri, 18 Dec 2020 08:44:28 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:date:in-reply-to:message-id:subject :from:to; bh=3VUHEO+si9B6ymY78I7rSRCFSjhEwSbJ7aJimbG4XBA=; b=TVlV7AwKbjQKx0+t5YzlEIp2Z+gWBU6TKxPGpdBlEPeMPsYG9g3FNbIld9C1UGd+1a IbKCTt+FEvTZNcmO0z+qb/xzxfYZY78gPxbqWJh+NTkyEDy3Tx0zGrG39P+/MH84oIA4 UdLIwrxharD7cu9bUDGTJA5yV1eE5dx4fjm8NRsO7ihZV41bRrF898lw5N7j7ivEnZKD /LAe1jK1B6yi2og64PolRH0ZG5DN+0xE0xoExcNZpzgoUWjesMXTzJu63H/nK4nCbaVM rHKdC4IaLGK6XJsaGVKoTeZQ23yBnfFH6AyP03APVwCoTa2btLQ4dBkfcxU5Y/LQrGqR SX2A== X-Gm-Message-State: AOAM5332CCNXspUia2lOIa6huNO17ae+R3TpzTFVvcbfPxfgzniS3oxJ dG0ug2893bAlF9fpQXQgekzZl4tiJFmogPluyJLdrXj/BvUd X-Google-Smtp-Source: ABdhPJxwkQT7qvnYFzpxeY/oQYydehjpHWbtZsmMyWZY5LjbZzOT49BWANX3PhKMcxuvvpeFyKSmg31hXbssHgbGVAoDZXTMtFGw MIME-Version: 1.0 X-Received: by 2002:a92:58dc:: with SMTP id z89mr3156048ilf.11.1608309843158; Fri, 18 Dec 2020 08:44:03 -0800 (PST) Date: Fri, 18 Dec 2020 08:44:03 -0800 In-Reply-To: X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000e3ec8005b6bfd042@google.com> Subject: Re: KASAN: use-after-free Read in idr_for_each (2) From: syzbot To: asml.silence@gmail.com, axboe@kernel.dk, io-uring@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: KASAN: use-after-free Read in idr_for_each ================================================================== BUG: KASAN: use-after-free in radix_tree_next_slot include/linux/radix-tree.h:422 [inline] BUG: KASAN: use-after-free in idr_for_each+0x206/0x220 lib/idr.c:202 Read of size 8 at addr ffff888042e76040 by task kworker/u4:5/3340 CPU: 0 PID: 3340 Comm: kworker/u4:5 Not tainted 5.10.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound io_ring_exit_work Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 print_address_description.constprop.0.cold+0xae/0x4c8 mm/kasan/report.c:385 __kasan_report mm/kasan/report.c:545 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562 radix_tree_next_slot include/linux/radix-tree.h:422 [inline] idr_for_each+0x206/0x220 lib/idr.c:202 io_destroy_buffers fs/io_uring.c:8541 [inline] io_ring_ctx_free fs/io_uring.c:8564 [inline] io_ring_exit_work+0x394/0x730 fs/io_uring.c:8639 process_one_work+0x98d/0x1630 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Allocated by task 28625: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:461 slab_post_alloc_hook mm/slab.h:512 [inline] slab_alloc_node mm/slub.c:2889 [inline] slab_alloc mm/slub.c:2897 [inline] kmem_cache_alloc+0x145/0x350 mm/slub.c:2902 radix_tree_node_alloc.constprop.0+0x7c/0x350 lib/radix-tree.c:274 idr_get_free+0x554/0xa60 lib/radix-tree.c:1504 idr_alloc_u32+0x170/0x2d0 lib/idr.c:46 idr_alloc+0xc2/0x130 lib/idr.c:87 io_provide_buffers fs/io_uring.c:4230 [inline] io_issue_sqe+0x3681/0x44e0 fs/io_uring.c:6264 __io_queue_sqe+0x228/0x1120 fs/io_uring.c:6477 io_queue_sqe+0x631/0x10f0 fs/io_uring.c:6543 io_submit_sqe fs/io_uring.c:6616 [inline] io_submit_sqes+0x135a/0x2530 fs/io_uring.c:6864 __do_sys_io_uring_enter+0x591/0x1c00 fs/io_uring.c:9174 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 8890: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:352 __kasan_slab_free+0x102/0x140 mm/kasan/common.c:422 slab_free_hook mm/slub.c:1544 [inline] slab_free_freelist_hook+0x5d/0x150 mm/slub.c:1577 slab_free mm/slub.c:3140 [inline] kmem_cache_free+0x82/0x360 mm/slub.c:3156 rcu_do_batch kernel/rcu/tree.c:2489 [inline] rcu_core+0x75d/0xf80 kernel/rcu/tree.c:2723 __do_softirq+0x2bc/0xa77 kernel/softirq.c:343 Last potentially related work creation: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_record_aux_stack+0xc0/0xf0 mm/kasan/generic.c:343 __call_rcu kernel/rcu/tree.c:2965 [inline] call_rcu+0xbb/0x710 kernel/rcu/tree.c:3038 radix_tree_node_free lib/radix-tree.c:308 [inline] delete_node+0x591/0x8c0 lib/radix-tree.c:571 __radix_tree_delete+0x190/0x370 lib/radix-tree.c:1377 radix_tree_delete_item+0xe7/0x230 lib/radix-tree.c:1428 __io_remove_buffers fs/io_uring.c:4122 [inline] __io_remove_buffers fs/io_uring.c:4101 [inline] __io_destroy_buffers+0x161/0x200 fs/io_uring.c:8535 idr_for_each+0x113/0x220 lib/idr.c:208 io_destroy_buffers fs/io_uring.c:8541 [inline] io_ring_ctx_free fs/io_uring.c:8564 [inline] io_ring_exit_work+0x394/0x730 fs/io_uring.c:8639 process_one_work+0x98d/0x1630 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Second to last potentially related work creation: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_record_aux_stack+0xc0/0xf0 mm/kasan/generic.c:343 __call_rcu kernel/rcu/tree.c:2965 [inline] call_rcu+0xbb/0x710 kernel/rcu/tree.c:3038 xa_node_free lib/xarray.c:258 [inline] xas_delete_node lib/xarray.c:494 [inline] update_node lib/xarray.c:756 [inline] xas_store+0xbeb/0x1c10 lib/xarray.c:841 __xa_erase lib/xarray.c:1489 [inline] xa_erase+0xb0/0x170 lib/xarray.c:1510 io_uring_del_task_file fs/io_uring.c:8889 [inline] __io_uring_files_cancel+0xdbf/0x1550 fs/io_uring.c:8925 io_uring_files_cancel include/linux/io_uring.h:51 [inline] exit_files+0xe4/0x170 fs/file.c:431 do_exit+0xb4f/0x2a00 kernel/exit.c:818 do_group_exit+0x125/0x310 kernel/exit.c:920 get_signal+0x3e9/0x2160 kernel/signal.c:2770 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811 handle_signal_work kernel/entry/common.c:147 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x124/0x200 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff888042e76000 which belongs to the cache radix_tree_node of size 576 The buggy address is located 64 bytes inside of 576-byte region [ffff888042e76000, ffff888042e76240) The buggy address belongs to the page: page:0000000090e8be83 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x42e76 head:0000000090e8be83 order:1 compound_mapcount:0 flags: 0xfff00000010200(slab|head) raw: 00fff00000010200 dead000000000100 dead000000000122 ffff88801084db40 raw: ffff888042e76580 00000000800b000a 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888042e75f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888042e75f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888042e76000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888042e76080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888042e76100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Tested on: commit: dfea9fce io_uring: close a small race gap for files cancel git tree: git://git.kernel.dk/linux-block console output: https://syzkaller.appspot.com/x/log.txt?x=1263a46b500000 kernel config: https://syzkaller.appspot.com/x/.config?x=4db50a97037d9f3e dashboard link: https://syzkaller.appspot.com/bug?extid=12056a09a0311d758e60 compiler: gcc (GCC) 10.1.0-syz 20200507