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=-0.4 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 67F9DC67863 for ; Sat, 20 Oct 2018 16:32:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 17F662157C for ; Sat, 20 Oct 2018 16:32:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 17F662157C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727673AbeJUAnF (ORCPT ); Sat, 20 Oct 2018 20:43:05 -0400 Received: from mail-it1-f198.google.com ([209.85.166.198]:43783 "EHLO mail-it1-f198.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727543AbeJUAnE (ORCPT ); Sat, 20 Oct 2018 20:43:04 -0400 Received: by mail-it1-f198.google.com with SMTP id w137-v6so7389956itc.8 for ; Sat, 20 Oct 2018 09:32:04 -0700 (PDT) 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=HEy+It0tLXkVH4Tm+ODZuTlfqoxtNNos/ZPqHPfcT34=; b=jn1WQSbu8+0BtWTv5qCNPdvPYJPJ4AYluZOd9VCLm4JSNWlMBNKCRQK9LA0HEWqqPi O3y+6OUi2kD0KWnUyW3+0KrsafYXz1PJT4ZOMECBoI1RxBEvnXC/jx9YyfRvwfdOH132 Sg3szEymi9ku2RJSBNdRvsucS68/sMCQSWMOsuLP3dVf4T8kOM/Q8bFJoTJAB0cuDShv 7KMfOgWzka6B+lDdVu9bGzl5vKJLDcxn368i6ABPZipXq9nlnzeBjfoGywRmPiObpea6 YS6Zwq48YYVX2SGlaVe5h1Fn6S5rOywDeLVXMD4gIuagFupCkFUc5wN8SNEbVIVw0T9j 923w== X-Gm-Message-State: ABuFfohz5kqG0jNROb/nNqM9dw+BNEogzgJSWhNr5Eq44hPAfsjgLSe2 tzNWZEd19V9jXGzd850n20XF4FkAUjIz8db6EZ1HAwPlbmYA X-Google-Smtp-Source: ACcGV60GCeHs3tjW2anWO8ryO44n7y8KNdbNHGnVk1KJHQ5wtfqLs14MlDRVeDiB/JLDDSEBfdgq2N62hhSsAuPY3AQM3dcbW5wA MIME-Version: 1.0 X-Received: by 2002:a02:3b58:: with SMTP id i24-v6mr32631628jaf.25.1540053123759; Sat, 20 Oct 2018 09:32:03 -0700 (PDT) Date: Sat, 20 Oct 2018 09:32:03 -0700 In-Reply-To: <000000000000140c370577db5ece@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000006089ec0578ab8f08@google.com> Subject: Re: KASAN: use-after-free Read in debugfs_remove (3) From: syzbot To: axboe@kernel.dk, gregkh@linuxfoundation.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, rafael@kernel.org, rostedt@goodmis.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org syzbot has found a reproducer for the following crash on: HEAD commit: 270b77a0f30e Merge tag 'drm-fixes-2018-10-20-1' of git://a.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1678d019400000 kernel config: https://syzkaller.appspot.com/x/.config?x=b3f55cb3dfcc6c33 dashboard link: https://syzkaller.appspot.com/bug?extid=903b72a010ad6b7a40f2 compiler: gcc (GCC) 8.0.1 20180413 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1248e21d400000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+903b72a010ad6b7a40f2@syzkaller.appspotmail.com overlayfs: missing 'lowerdir' overlayfs: missing 'lowerdir' overlayfs: missing 'lowerdir' overlayfs: missing 'lowerdir' ================================================================== BUG: KASAN: use-after-free in debugfs_remove+0x10b/0x130 fs/debugfs/inode.c:682 Read of size 8 at addr ffff8801c3d48a60 by task kworker/1:3/5820 CPU: 1 PID: 5820 Comm: kworker/1:3 Not tainted 4.19.0-rc8+ #72 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events __blk_release_queue Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c4/0x2b4 lib/dump_stack.c:113 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 debugfs_remove+0x10b/0x130 fs/debugfs/inode.c:682 blk_trace_free+0x35/0x130 kernel/trace/blktrace.c:312 blk_trace_cleanup kernel/trace/blktrace.c:339 [inline] __blk_trace_remove+0x7a/0xa0 kernel/trace/blktrace.c:352 blk_trace_shutdown+0x63/0x80 kernel/trace/blktrace.c:752 __blk_release_queue+0x22d/0x500 block/blk-sysfs.c:852 process_one_work+0xc90/0x1b90 kernel/workqueue.c:2153 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296 kobject: 'mq' (00000000f4ee6bf8): kobject_uevent_env: filter function caused the event to drop! kobject: '0' (000000001977fe41): kobject_add_internal: parent: 'mq', set: '' kthread+0x35a/0x420 kernel/kthread.c:246 kobject: 'cpu0' (00000000e409d4ee): kobject_add_internal: parent: '0', set: '' ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 kobject: 'cpu1' (000000004ffe025c): kobject_add_internal: parent: '0', set: '' Allocated by task 11189: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 kobject: 'queue' (00000000c1b3424e): kobject_uevent_env kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc+0x12e/0x730 mm/slab.c:3554 __d_alloc+0xc8/0xcc0 fs/dcache.c:1614 d_alloc+0x96/0x380 fs/dcache.c:1698 d_alloc_parallel+0x15a/0x1f40 fs/dcache.c:2441 __lookup_slow+0x1e6/0x540 fs/namei.c:1654 kobject: 'queue' (00000000c1b3424e): kobject_uevent_env: filter function caused the event to drop! lookup_one_len+0x1d8/0x220 fs/namei.c:2543 start_creating+0xc6/0x200 fs/debugfs/inode.c:308 __debugfs_create_file+0x63/0x400 fs/debugfs/inode.c:347 debugfs_create_file+0x57/0x70 fs/debugfs/inode.c:399 do_blk_trace_setup+0x454/0xda0 kernel/trace/blktrace.c:528 __blk_trace_setup+0xd5/0x180 kernel/trace/blktrace.c:577 blk_trace_ioctl+0x17a/0x2f0 kernel/trace/blktrace.c:716 blkdev_ioctl+0x8bc/0x2010 block/ioctl.c:587 block_ioctl+0xee/0x130 fs/block_dev.c:1883 kobject: 'iosched' (000000001a1643a8): kobject_add_internal: parent: 'queue', set: '' vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702 __do_sys_ioctl fs/ioctl.c:709 [inline] __se_sys_ioctl fs/ioctl.c:707 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe kobject: 'iosched' (000000001a1643a8): kobject_uevent_env Freed by task 5443: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kmem_cache_free+0x83/0x290 mm/slab.c:3756 __d_free+0x20/0x30 fs/dcache.c:257 __rcu_reclaim kernel/rcu/rcu.h:236 [inline] rcu_do_batch kernel/rcu/tree.c:2576 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2880 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2847 [inline] rcu_process_callbacks+0xf23/0x2670 kernel/rcu/tree.c:2864 kobject: 'iosched' (000000001a1643a8): kobject_uevent_env: filter function caused the event to drop! __do_softirq+0x30b/0xad8 kernel/softirq.c:292 The buggy address belongs to the object at ffff8801c3d48a20 which belongs to the cache dentry of size 288 The buggy address is located 64 bytes inside of 288-byte region [ffff8801c3d48a20, ffff8801c3d48b40) The buggy address belongs to the page: page:ffffea00070f5200 count:1 mapcount:0 mapping:ffff8801da978c40 index:0xffff8801c3d488c0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffffea000726ebc8 ffffea00071b0988 ffff8801da978c40 kobject: 'integrity' (000000000b36b365): kobject_add_internal: parent: 'loop0', set: '' raw: ffff8801c3d488c0 ffff8801c3d48080 000000010000000a 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c3d48900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801c3d48980: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > ffff8801c3d48a00: fc fc fc fc fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801c3d48a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb kobject: 'integrity' (000000000b36b365): kobject_uevent_env ffff8801c3d48b00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================