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 61FAEC4363C for ; Wed, 7 Oct 2020 11:31:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1301E2076C for ; Wed, 7 Oct 2020 11:31:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727328AbgJGLbT (ORCPT ); Wed, 7 Oct 2020 07:31:19 -0400 Received: from mail-io1-f80.google.com ([209.85.166.80]:39560 "EHLO mail-io1-f80.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726096AbgJGLbS (ORCPT ); Wed, 7 Oct 2020 07:31:18 -0400 Received: by mail-io1-f80.google.com with SMTP id s135so1105099ios.6 for ; Wed, 07 Oct 2020 04:31:17 -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:message-id:subject:from:to; bh=vjtRuHi2Hc6BiX+YCDt+i6nOG7vmNbQPu3H+COlDXvc=; b=kBSUXAVm9avaFICLfs9cazeQtr6XjIUu7PfBguHHBIl//OP4hnNQp0vgDwZZbhq+28 +iFumTCflKcsIdwLprhhPmTJrgc86LAwT6jQIvwJNaByXVzMlHhmv4gaikydzv1oosIo 6gxF9o7HLkJzL3a4MnaRBj79GNjfco5Pm8bR1o+Ha4tzNSYrLR5xHzs66et36xD5Mcws MCN/787PUaVbfnHBeSHJNheU7epniGGS93xcSgHD96Ao699qnTXuf387vR8qkx+ssSYb t5eb+BqESilKKvG64SJYarGe7cYsV5GRGyJnvorc9d2OdcjKy16XwCVt8aOhBtaJajhy fCOg== X-Gm-Message-State: AOAM531jio/ChZllvfW/xIFNCbA9YhLtjXvRRmTc16ad+PB5uBgbHWnc 4e/gtNGd/9CDXrmAVrIfEtcB1MYtI9hdqwlRS7LzAXn34NRj X-Google-Smtp-Source: ABdhPJyznvfWXXedrCqL5DcgMCDv/+9tBiX1/p6fdQaxxU7KE1KLFFgKG+Fg3Rm8tixZrRivTm+Z2vTGavwaOFvPa3XFON/nDHkb MIME-Version: 1.0 X-Received: by 2002:a05:6602:54:: with SMTP id z20mr1906863ioz.85.1602070276914; Wed, 07 Oct 2020 04:31:16 -0700 (PDT) Date: Wed, 07 Oct 2020 04:31:16 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000c2c2f005b1130def@google.com> Subject: KASAN: use-after-free Read in __d_alloc From: syzbot To: 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: linux-kernel@vger.kernel.org Hello, syzbot found the following issue on: HEAD commit: d3d45f82 Merge tag 'pinctrl-v5.9-2' of git://git.kernel.or.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1615acaf900000 kernel config: https://syzkaller.appspot.com/x/.config?x=89ab6a0c48f30b49 dashboard link: https://syzkaller.appspot.com/bug?extid=0842a31cc990d5a8a60c compiler: gcc (GCC) 10.1.0-syz 20200507 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+0842a31cc990d5a8a60c@syzkaller.appspotmail.com ================================================================== BUG: KASAN: use-after-free in memcpy include/linux/string.h:406 [inline] BUG: KASAN: use-after-free in __d_alloc+0x19a/0x950 fs/dcache.c:1740 Read of size 1 at addr ffff8880928f30c0 by task kworker/0:3/7298 CPU: 0 PID: 7298 Comm: kworker/0:3 Not tainted 5.9.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: afs afs_manage_cell Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x198/0x1fd lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 check_memory_region_inline mm/kasan/generic.c:186 [inline] check_memory_region+0x13d/0x180 mm/kasan/generic.c:192 memcpy+0x20/0x60 mm/kasan/common.c:105 memcpy include/linux/string.h:406 [inline] __d_alloc+0x19a/0x950 fs/dcache.c:1740 d_alloc+0x4a/0x230 fs/dcache.c:1788 d_alloc_parallel+0xe9/0x18e0 fs/dcache.c:2540 __lookup_slow+0x193/0x480 fs/namei.c:1529 lookup_one_len+0x163/0x190 fs/namei.c:2562 afs_dynroot_mkdir+0x167/0x250 fs/afs/dynroot.c:293 afs_activate_cell fs/afs/cell.c:632 [inline] afs_manage_cell+0x6d2/0x11c0 fs/afs/cell.c:697 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 process_scheduled_works kernel/workqueue.c:2331 [inline] worker_thread+0x82b/0x1120 kernel/workqueue.c:2417 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Allocated by task 13591: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 __do_kmalloc mm/slab.c:3659 [inline] __kmalloc+0x1b0/0x360 mm/slab.c:3668 kmalloc include/linux/slab.h:559 [inline] afs_alloc_cell fs/afs/cell.c:157 [inline] afs_lookup_cell+0x5e9/0x1440 fs/afs/cell.c:262 afs_parse_source fs/afs/super.c:290 [inline] afs_parse_param+0x404/0x8c0 fs/afs/super.c:326 vfs_parse_fs_param fs/fs_context.c:117 [inline] vfs_parse_fs_param+0x203/0x550 fs/fs_context.c:98 vfs_parse_fs_string+0xe6/0x150 fs/fs_context.c:161 generic_parse_monolithic+0x16f/0x1f0 fs/fs_context.c:201 do_new_mount fs/namespace.c:2871 [inline] path_mount+0x133f/0x20a0 fs/namespace.c:3192 do_mount fs/namespace.c:3205 [inline] __do_sys_mount fs/namespace.c:3413 [inline] __se_sys_mount fs/namespace.c:3390 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3390 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 6891: 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:355 __kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422 __cache_free mm/slab.c:3422 [inline] kfree+0x10e/0x2b0 mm/slab.c:3760 afs_cell_destroy+0x1b0/0x240 fs/afs/cell.c:500 rcu_do_batch kernel/rcu/tree.c:2430 [inline] rcu_core+0x5ca/0x1130 kernel/rcu/tree.c:2658 __do_softirq+0x1f8/0xb23 kernel/softirq.c:298 The buggy address belongs to the object at ffff8880928f30c0 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes inside of 32-byte region [ffff8880928f30c0, ffff8880928f30e0) The buggy address belongs to the page: page:00000000ff82e524 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880928f3fc1 pfn:0x928f3 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002881b08 ffffea000299dc88 ffff8880aa040100 raw: ffff8880928f3fc1 ffff8880928f3000 0000000100000039 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880928f2f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880928f3000: 00 00 01 fc fc fc fc fc fa fb fb fb fc fc fc fc >ffff8880928f3080: 00 01 fc fc fc fc fc fc fa fb fb fb fc fc fc fc ^ ffff8880928f3100: 00 00 01 fc fc fc fc fc fb fb fb fb fc fc fc fc ffff8880928f3180: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ================================================================== --- This report is generated by a bot. 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