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=-5.4 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 4F433C432C3 for ; Tue, 19 Nov 2019 07:11:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 20625222DF for ; Tue, 19 Nov 2019 07:11:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727302AbfKSHLI (ORCPT ); Tue, 19 Nov 2019 02:11:08 -0500 Received: from mail-io1-f71.google.com ([209.85.166.71]:52414 "EHLO mail-io1-f71.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726555AbfKSHLH (ORCPT ); Tue, 19 Nov 2019 02:11:07 -0500 Received: by mail-io1-f71.google.com with SMTP id o5so15287632iob.19 for ; Mon, 18 Nov 2019 23:11:07 -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:message-id:subject:from:to; bh=1v1aJGS9HsUrUeldziyx6a61zXZusa4khlXNwtE+IaY=; b=Z439Yp7uRhmhj5QiFC4ATr02dKwo29z5uMxeln3tqnu6hfLF5BUP9pgwymaJx5bujz UkRtQ1iztkUnw1t6SIj97l20fthoDiOkpVcP71uKqCaDRMHf415kv88YulwDPh6Kd7Ta rd1QQ0XEe/AZNiHjDIbpZ1e8hzmC70bXT3KPsDXWfF4DgsbVO1B0KxRaVCLm2ZfQgz7A 7Lf9PqpV2/iTxycaotAl8ZYEHV7oGdnhqmim4AKevfRUseeZ+Shf6CkQ0I+yHyDJf2zO YwhYQcXe880EcIt+2Mh6TcfhvmRPaIB6KnmDXBO4yCQWT1A6sfKpUKDVnueHA5QNuX9O z+Yw== X-Gm-Message-State: APjAAAXnnVhfP8YrGgDJfOt9Ni9F3rYnscG6GxbBUQpbm4DTKW7gvZaY tVjC8mytJYhDKMp9+BETR9u+4KPMNpxAJ6ELA4iCbrAqZQHa X-Google-Smtp-Source: APXvYqxdZZYLE8OwNy2FHsJ6YSwh9lfsT9xQC0okfneLSAj5kdGsa3xWwAJ48k79fXa8r+kRMVUkJ2bjDtHRQJYu9sPljXFHVOaK MIME-Version: 1.0 X-Received: by 2002:a05:6e02:cd0:: with SMTP id c16mr22275430ilj.226.1574147466718; Mon, 18 Nov 2019 23:11:06 -0800 (PST) Date: Mon, 18 Nov 2019 23:11:06 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <00000000000093f8c20597adc469@google.com> Subject: KASAN: use-after-free Read in blkcg_print_stat (2) From: syzbot To: axboe@kernel.dk, cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, tj@kernel.org 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 Hello, syzbot found the following crash on: HEAD commit: fe30021c Merge branch 'x86-urgent-for-linus' of git://git... git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1196cb3ae00000 kernel config: https://syzkaller.appspot.com/x/.config?x=1aab6d4187ddf667 dashboard link: https://syzkaller.appspot.com/bug?extid=9bfadf534cf2fd1b5eb8 compiler: gcc (GCC) 9.0.0 20181231 (experimental) Unfortunately, I don't have any reproducer for this crash yet. IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+9bfadf534cf2fd1b5eb8@syzkaller.appspotmail.com ================================================================== BUG: KASAN: use-after-free in dev_name include/linux/device.h:1342 [inline] BUG: KASAN: use-after-free in blkg_dev_name block/blk-cgroup.c:498 [inline] BUG: KASAN: use-after-free in blkcg_print_stat+0xb26/0xc00 block/blk-cgroup.c:942 Read of size 8 at addr ffff8880a01b2050 by task syz-executor.1/16053 CPU: 0 PID: 16053 Comm: syz-executor.1 Not tainted 5.4.0-rc7+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506 kasan_report+0x12/0x20 mm/kasan/common.c:634 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 dev_name include/linux/device.h:1342 [inline] blkg_dev_name block/blk-cgroup.c:498 [inline] blkcg_print_stat+0xb26/0xc00 block/blk-cgroup.c:942 cgroup_seqfile_show+0x1a8/0x300 kernel/cgroup/cgroup.c:3816 kernfs_seq_show+0x14f/0x1b0 fs/kernfs/file.c:167 seq_read+0x4ca/0x1110 fs/seq_file.c:229 kernfs_fop_read+0xed/0x560 fs/kernfs/file.c:251 do_loop_readv_writev fs/read_write.c:714 [inline] do_loop_readv_writev fs/read_write.c:701 [inline] do_iter_read+0x4a4/0x660 fs/read_write.c:935 vfs_readv+0xf0/0x160 fs/read_write.c:997 do_readv+0x15b/0x330 fs/read_write.c:1034 __do_sys_readv fs/read_write.c:1125 [inline] __se_sys_readv fs/read_write.c:1122 [inline] __x64_sys_readv+0x75/0xb0 fs/read_write.c:1122 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a639 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fd336772c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000013 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a639 RDX: 00000000000001a5 RSI: 00000000200002c0 RDI: 0000000000000004 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd3367736d4 R13: 00000000004c7ecd R14: 00000000004de160 R15: 00000000ffffffff Allocated by task 12327: save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_kmalloc mm/kasan/common.c:510 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:483 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:524 kmem_cache_alloc_trace+0x158/0x790 mm/slab.c:3550 kmalloc include/linux/slab.h:556 [inline] kzalloc include/linux/slab.h:690 [inline] device_create_groups_vargs+0x8e/0x270 drivers/base/core.c:2828 device_create_vargs+0x45/0x60 drivers/base/core.c:2886 bdi_register_va.part.0+0x91/0x940 mm/backing-dev.c:940 bdi_register_va mm/backing-dev.c:976 [inline] bdi_register+0x12a/0x140 mm/backing-dev.c:973 bdi_register_owner+0x6a/0x110 mm/backing-dev.c:983 __device_add_disk+0xe09/0x1230 block/genhd.c:739 device_add_disk+0x2b/0x40 block/genhd.c:763 add_disk include/linux/genhd.h:429 [inline] loop_add+0x635/0x8d0 drivers/block/loop.c:2061 loop_control_ioctl drivers/block/loop.c:2162 [inline] loop_control_ioctl+0x165/0x360 drivers/block/loop.c:2144 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 16049: save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] kasan_set_free_info mm/kasan/common.c:332 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:471 kasan_slab_free+0xe/0x10 mm/kasan/common.c:480 __cache_free mm/slab.c:3425 [inline] kfree+0x10a/0x2c0 mm/slab.c:3756 device_create_release+0x16/0x20 drivers/base/power/wakeup_stats.c:130 device_release+0x7a/0x210 drivers/base/core.c:1101 kobject_cleanup lib/kobject.c:693 [inline] kobject_release lib/kobject.c:722 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put.cold+0x289/0x2e6 lib/kobject.c:739 put_device drivers/base/core.c:2301 [inline] device_unregister+0x28/0x40 drivers/base/core.c:2409 bdi_unregister+0x428/0x610 mm/backing-dev.c:1016 del_gendisk+0x896/0xb30 block/genhd.c:810 loop_remove+0x3c/0xd0 drivers/block/loop.c:2079 loop_control_ioctl drivers/block/loop.c:2178 [inline] loop_control_ioctl+0x320/0x360 drivers/block/loop.c:2144 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a01b2000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 80 bytes inside of 2048-byte region [ffff8880a01b2000, ffff8880a01b2800) The buggy address belongs to the page: page:ffffea0002806c80 refcount:1 mapcount:0 mapping:ffff8880aa400e00 index:0x0 raw: 01fffc0000000200 ffffea0002374088 ffffea0002730148 ffff8880aa400e00 raw: 0000000000000000 ffff8880a01b2000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a01b1f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a01b1f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ffff8880a01b2000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a01b2080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a01b2100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This bug is generated by a bot. 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