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=-3.7 required=3.0 tests=BAYES_00,FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 DF22FC43466 for ; Mon, 21 Sep 2020 10:33:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AFCB120684 for ; Mon, 21 Sep 2020 10:33:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726688AbgIUKdT (ORCPT ); Mon, 21 Sep 2020 06:33:19 -0400 Received: from mail-io1-f80.google.com ([209.85.166.80]:56016 "EHLO mail-io1-f80.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726367AbgIUKdS (ORCPT ); Mon, 21 Sep 2020 06:33:18 -0400 Received: by mail-io1-f80.google.com with SMTP id t187so9500613iof.22 for ; Mon, 21 Sep 2020 03:33:17 -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=TkUyzMkYz/c8/5hvltm5ed1HTbPYyQWLlHEIooENSiE=; b=f9y7r5nGfHtitbPeMkpTdRfBCjcbHJsNNyHC9ayWByuZEUuk79ydoUzAbp5xKiaw4J ftS/uWBjrIOQyAbjgKcCcGkW9g2rS6/40EUxFa3xQwSLMenl8s8kYamNGYnyb7T1emO6 XGSkcmm4UoP7fI+rqrItnZGp0VcHEdgWjGBuEJX9JkyAsrTt1bOeBesnYKVdEl2RIfMq ztGuEV4j69VsBf2Mwu6x6pi8vu+ErsUazX5Om9rxNE4ABk01vLaPkwhlSgjBrjTokdgw AWRHGJ3yJzxqCgckIA4DwdDMattBqcsvG+7w5iy8VjAKJiGLuD9AkDNrv4OzBq7PRyyX trOw== X-Gm-Message-State: AOAM531K/icRuGf2NPStibGm7+QwDFW/isFsql0tC4s37o2pGAgMeemX 3LolLnznMnCUD8YedvyhtfsONAZGOqxb9QSwC91wK1bj11BT X-Google-Smtp-Source: ABdhPJzGXxUiEInu/JMkAk+OuWugeCE3xYd/24sugKd3CrVst9ArkjXt3vF9NV/C7llboeCyQhrjsnxTHC26ZDvbvOUVzh9WjZxy MIME-Version: 1.0 X-Received: by 2002:a02:ccae:: with SMTP id t14mr32262614jap.63.1600684397439; Mon, 21 Sep 2020 03:33:17 -0700 (PDT) Date: Mon, 21 Sep 2020 03:33:17 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000e82e1a05afd0605d@google.com> Subject: KASAN: use-after-free Read in afs_deactivate_cell (2) From: syzbot To: dhowells@redhat.com, linux-afs@lists.infradead.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com 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: 325d0eab Merge branch 'akpm' (patches from Andrew) git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=15ec729b900000 kernel config: https://syzkaller.appspot.com/x/.config?x=8d39f8ae68f9dcd5 dashboard link: https://syzkaller.appspot.com/bug?extid=a5e4946b04d6ca8fa5f3 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+a5e4946b04d6ca8fa5f3@syzkaller.appspotmail.com ================================================================== BUG: KASAN: use-after-free in __hlist_del include/linux/list.h:826 [inline] BUG: KASAN: use-after-free in hlist_del_rcu include/linux/rculist.h:487 [inline] BUG: KASAN: use-after-free in afs_deactivate_cell+0x165/0x1a0 fs/afs/cell.c:647 Read of size 8 at addr ffff888090699880 by task kworker/0:3/7433 CPU: 0 PID: 7433 Comm: kworker/0:3 Not tainted 5.9.0-rc5-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 __hlist_del include/linux/list.h:826 [inline] hlist_del_rcu include/linux/rculist.h:487 [inline] afs_deactivate_cell+0x165/0x1a0 fs/afs/cell.c:647 afs_manage_cell+0x326/0x11c0 fs/afs/cell.c:721 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 19085: 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 kmem_cache_alloc_trace+0x174/0x300 mm/slab.c:3550 kmalloc include/linux/slab.h:554 [inline] kzalloc include/linux/slab.h:666 [inline] afs_alloc_cell fs/afs/cell.c:151 [inline] afs_lookup_cell+0x5c8/0x1440 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 9: 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:3418 [inline] kfree+0x10e/0x2b0 mm/slab.c:3756 rcu_do_batch kernel/rcu/tree.c:2428 [inline] rcu_core+0x5ca/0x1130 kernel/rcu/tree.c:2656 __do_softirq+0x1f8/0xb23 kernel/softirq.c:298 Last call_rcu(): kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_record_aux_stack+0x82/0xb0 mm/kasan/generic.c:346 __call_rcu kernel/rcu/tree.c:2894 [inline] call_rcu+0x15e/0x7c0 kernel/rcu/tree.c:2968 afs_manage_cell+0x250/0x11c0 fs/afs/cell.c:751 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 The buggy address belongs to the object at ffff888090699800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 128 bytes inside of 1024-byte region [ffff888090699800, ffff888090699c00) The buggy address belongs to the page: page:00000000d3e3a7d0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x90699 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002558fc8 ffffea0001240988 ffff8880aa040700 raw: 0000000000000000 ffff888090699000 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888090699780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888090699800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888090699880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888090699900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888090699980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot.