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 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 2FB5AC3567B for ; Mon, 24 Feb 2020 09:18:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0E96B2082E for ; Mon, 24 Feb 2020 09:18:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727758AbgBXJSQ (ORCPT ); Mon, 24 Feb 2020 04:18:16 -0500 Received: from mail-io1-f70.google.com ([209.85.166.70]:56921 "EHLO mail-io1-f70.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727168AbgBXJSO (ORCPT ); Mon, 24 Feb 2020 04:18:14 -0500 Received: by mail-io1-f70.google.com with SMTP id d13so14338268ioo.23 for ; Mon, 24 Feb 2020 01:18:14 -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=Mf+jlK9KZr8krnerxo+HMUq0lwL4/YXg+aLzSPa1uSo=; b=b+8z42aJeGxOkzzlPu0sCX+3mcRJkBGhLuZshNkDBu2KeuT5eUQEnkHeBWOuLkhweg RdeJABnH3WPX4llVJ60M0ORffuVW3TQJAIFqLnqLqHiyBA9kstjT7tojZZdZqmQTJnjB hbHh5qy76w3aJ8aZdiB4kNIh5PPuN3FCEw28kxC+ntfSp0DDYHdKBswrOKWwI6ap6CKM r0rQMsE4nQLAuhmuIkZeior7nA35Mt51KcnG3k3jPGTo5fKP8d6T5v6GaDHwTAy1C2ku c+rfsT39jm4o2L6vBAruAPm/qN7IeO6kmCBzg8nFB0t0CWvuGrIeF8QGd/cLRySi+W7f pDhw== X-Gm-Message-State: APjAAAUHpW4z0wFeDp4fB67cLNgqWi/5smduK19cshOh9wbBIgmoO3F9 ApEGVHZzJUovP13ZEV03kEEabwjQ0v1uPwHhA9lH6gbwK/xZ X-Google-Smtp-Source: APXvYqwwUHoOiTOqYw1Z4Rj4yUORcLtd3JosVaujD6a0RENc1EnfPrfxO/lVu+Nyd4TO4+o5xEPX3erXgcxmCWYyWyiNYH2H0L3A MIME-Version: 1.0 X-Received: by 2002:a92:1a12:: with SMTP id a18mr57454946ila.10.1582535894205; Mon, 24 Feb 2020 01:18:14 -0800 (PST) Date: Mon, 24 Feb 2020 01:18:14 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000d18d83059f4ed9ad@google.com> Subject: KASAN: use-after-free Read in vt_do_kdgkb_ioctl From: syzbot To: dmitry.torokhov@gmail.com, gregkh@linuxfoundation.org, jslaby@suse.com, linux-kernel@vger.kernel.org, rei4dan@gmail.com, slyfox@gentoo.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" 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: 54dedb5b Merge tag 'for-linus-5.6-rc3-tag' of git://git.ke.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=100403d9e00000 kernel config: https://syzkaller.appspot.com/x/.config?x=3b8906eb6a7d6028 dashboard link: https://syzkaller.appspot.com/bug?extid=a58bfd517766aef83043 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+a58bfd517766aef83043@syzkaller.appspotmail.com ================================================================== BUG: KASAN: use-after-free in vt_do_kdgkb_ioctl+0xb24/0xb50 drivers/tty/vt/keyboard.c:2025 Read of size 1 at addr ffff8880a4a8c801 by task syz-executor.4/27890 CPU: 1 PID: 27890 Comm: syz-executor.4 Not tainted 5.6.0-rc2-syzkaller #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/0x32 mm/kasan/report.c:506 kasan_report+0x12/0x20 mm/kasan/common.c:641 __asan_report_load1_noabort+0x14/0x20 mm/kasan/generic_report.c:132 vt_do_kdgkb_ioctl+0xb24/0xb50 drivers/tty/vt/keyboard.c:2025 vt_ioctl+0x47e/0x26c0 drivers/tty/vt/vt_ioctl.c:549 tty_ioctl+0xa37/0x14f0 drivers/tty/tty_io.c:2660 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x123/0x180 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:770 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c429 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:00007f0f2868cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f0f2868d6d4 RCX: 000000000045c429 RDX: 0000000020000200 RSI: 0000000000004b48 RDI: 0000000000000003 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000041a R14: 00000000004c676d R15: 000000000076bf2c Allocated by task 1548: save_stack+0x23/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc mm/kasan/common.c:515 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:488 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:529 __do_kmalloc mm/slab.c:3656 [inline] __kmalloc+0x163/0x770 mm/slab.c:3665 kmalloc include/linux/slab.h:560 [inline] vt_do_kdgkb_ioctl+0x3d1/0xb50 drivers/tty/vt/keyboard.c:2078 vt_ioctl+0x47e/0x26c0 drivers/tty/vt/vt_ioctl.c:549 tty_ioctl+0xa37/0x14f0 drivers/tty/tty_io.c:2660 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x123/0x180 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:770 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 27892: save_stack+0x23/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] kasan_set_free_info mm/kasan/common.c:337 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:476 kasan_slab_free+0xe/0x10 mm/kasan/common.c:485 __cache_free mm/slab.c:3426 [inline] kfree+0x10a/0x2c0 mm/slab.c:3757 vt_do_kdgkb_ioctl+0x5b4/0xb50 drivers/tty/vt/keyboard.c:2104 vt_ioctl+0x47e/0x26c0 drivers/tty/vt/vt_ioctl.c:549 tty_ioctl+0xa37/0x14f0 drivers/tty/tty_io.c:2660 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x123/0x180 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:770 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a4a8c800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 1 bytes inside of 1024-byte region [ffff8880a4a8c800, ffff8880a4a8cc00) The buggy address belongs to the page: page:ffffea000292a300 refcount:1 mapcount:0 mapping:ffff8880aa400c40 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00026aa6c8 ffffea000210b1c8 ffff8880aa400c40 raw: 0000000000000000 ffff8880a4a8c000 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a4a8c700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a4a8c780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880a4a8c800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a4a8c880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a4a8c900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This bug 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 bug report. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot.