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 759CDC43603 for ; Sat, 7 Dec 2019 06:25:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3E8D12173E for ; Sat, 7 Dec 2019 06:25:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725923AbfLGGZJ (ORCPT ); Sat, 7 Dec 2019 01:25:09 -0500 Received: from mail-il1-f200.google.com ([209.85.166.200]:43981 "EHLO mail-il1-f200.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725869AbfLGGZJ (ORCPT ); Sat, 7 Dec 2019 01:25:09 -0500 Received: by mail-il1-f200.google.com with SMTP id j17so7031227ilc.10 for ; Fri, 06 Dec 2019 22:25:08 -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=j9m3lrvCXCpzSxM+tW4QOf6zVSZBLzxbD4R9FIlfwe8=; b=clTfx/coMYB8mywRfKfbp1aPzWH+T5lhfr1sDcOCybS6JhfdWhVIeyhBBAymHwKl1P IHzvrmbZYtU8FS2y/7m1XFeyno5VomLTRAhigKAOr3r2GZT8n8pu26jFRRnnxfI8XAGg AQtOqDnMMJjYKP2sVSjCTDFm7mdwKyaWl2yA8s6yqVWG+tjn25TN/MLyfyktISsGEsv5 0ibxwmWMrCqoEECSNSI0ucv3l3Asp0+MqqxsazKNaJPDnDNtjEvQmuodQAMo8yxoP2+y SfaLax/WUpnBNg+zqTrgjtnOL3IoZYajQY+jL2MoWFt0QXc6gtf38tAkwgg8gq2M4VSR ywJg== X-Gm-Message-State: APjAAAVukPrkV2HWD6WRiPJEsuxC0zSnQVVIK7auHTZBH3wzlFJ9Clfb P1yAz2n61BdhW6I6FZItDKDtHV8SU8aclyIFmQPqm+XnNFPI X-Google-Smtp-Source: APXvYqzcbP1i5iXtWa0x3COTXPqct38u54GHio/056rYZdiiYwd85nUttqGVNSnG+wxuaygr4c8dTn2O91+AImlAt7jLwipkZ4GK MIME-Version: 1.0 X-Received: by 2002:a05:6638:a2c:: with SMTP id 12mr17810458jao.60.1575699908609; Fri, 06 Dec 2019 22:25:08 -0800 (PST) Date: Fri, 06 Dec 2019 22:25:08 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <00000000000053539a0599173973@google.com> Subject: BUG: unable to handle kernel NULL pointer dereference in mem_serial_out From: syzbot To: andriy.shevchenko@linux.intel.com, asierra@xes-inc.com, ext-kimmo.rautkoski@vaisala.com, gregkh@linuxfoundation.org, jslaby@suse.com, kai.heng.feng@canonical.com, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, mika.westerberg@linux.intel.com, o.barta89@gmail.com, paulburton@kernel.org, sr@denx.de, syzkaller-bugs@googlegroups.com, yegorslists@googlemail.com Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: linux-serial-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org Hello, syzbot found the following crash on: HEAD commit: 7ada90eb Merge tag 'drm-next-2019-12-06' of git://anongit... git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=123ec282e00000 kernel config: https://syzkaller.appspot.com/x/.config?x=f07a23020fd7d21a dashboard link: https://syzkaller.appspot.com/bug?extid=f4f1e871965064ae689e compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17ab090ee00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17f127f2e00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+f4f1e871965064ae689e@syzkaller.appspotmail.com BUG: kernel NULL pointer dereference, address: 0000000000000002 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 9764a067 P4D 9764a067 PUD 9f995067 PMD 0 Oops: 0002 [#1] PREEMPT SMP KASAN CPU: 0 PID: 9687 Comm: syz-executor433 Not tainted 5.4.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:writeb arch/x86/include/asm/io.h:65 [inline] RIP: 0010:mem_serial_out+0x70/0x90 drivers/tty/serial/8250/8250_port.c:408 Code: e9 00 00 00 49 8d 7c 24 40 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 d3 e3 80 3c 02 00 75 19 48 63 db 49 03 5c 24 40 <44> 88 2b 5b 41 5c 41 5d 5d c3 e8 81 ed cf fd eb c0 e8 da ed cf fd RSP: 0018:ffffc90001de78e8 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000002 RCX: 0000000000000000 RDX: 1ffffffff181f40e RSI: ffffffff83e28776 RDI: ffffffff8c0fa070 RBP: ffffc90001de7900 R08: ffff8880919dc340 R09: ffffed10431ee1c6 R10: ffffed10431ee1c5 R11: ffff888218f70e2b R12: ffffffff8c0fa030 R13: 0000000000000001 R14: ffffc90001de7a40 R15: ffffffff8c0fa188 FS: 0000000001060880(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000002 CR3: 000000009e6b8000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_out drivers/tty/serial/8250/8250.h:118 [inline] serial8250_clear_fifos.part.0+0x3a/0xb0 drivers/tty/serial/8250/8250_port.c:557 serial8250_clear_fifos drivers/tty/serial/8250/8250_port.c:556 [inline] serial8250_do_startup+0x426/0x1cf0 drivers/tty/serial/8250/8250_port.c:2121 serial8250_startup+0x62/0x80 drivers/tty/serial/8250/8250_port.c:2329 uart_port_startup drivers/tty/serial/serial_core.c:219 [inline] uart_startup drivers/tty/serial/serial_core.c:258 [inline] uart_startup+0x452/0x980 drivers/tty/serial/serial_core.c:249 uart_set_info drivers/tty/serial/serial_core.c:998 [inline] uart_set_info_user+0x13b4/0x1cf0 drivers/tty/serial/serial_core.c:1023 tty_tiocsserial drivers/tty/tty_io.c:2506 [inline] tty_ioctl+0xf60/0x14f0 drivers/tty/tty_io.c:2648 vfs_ioctl fs/ioctl.c:47 [inline] file_ioctl fs/ioctl.c:545 [inline] do_vfs_ioctl+0x977/0x14e0 fs/ioctl.c:732 ksys_ioctl+0xab/0xd0 fs/ioctl.c:749 __do_sys_ioctl fs/ioctl.c:756 [inline] __se_sys_ioctl fs/ioctl.c:754 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:754 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x440219 Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 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 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffced648c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440219 RDX: 0000000020000240 RSI: 000000000000541f RDI: 0000000000000003 RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8 R10: 0000000000401b30 R11: 0000000000000246 R12: 0000000000401aa0 R13: 0000000000401b30 R14: 0000000000000000 R15: 0000000000000000 Modules linked in: CR2: 0000000000000002 ---[ end trace eaa11ffe82f3a763 ]--- RIP: 0010:writeb arch/x86/include/asm/io.h:65 [inline] RIP: 0010:mem_serial_out+0x70/0x90 drivers/tty/serial/8250/8250_port.c:408 Code: e9 00 00 00 49 8d 7c 24 40 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 d3 e3 80 3c 02 00 75 19 48 63 db 49 03 5c 24 40 <44> 88 2b 5b 41 5c 41 5d 5d c3 e8 81 ed cf fd eb c0 e8 da ed cf fd RSP: 0018:ffffc90001de78e8 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000002 RCX: 0000000000000000 RDX: 1ffffffff181f40e RSI: ffffffff83e28776 RDI: ffffffff8c0fa070 RBP: ffffc90001de7900 R08: ffff8880919dc340 R09: ffffed10431ee1c6 R10: ffffed10431ee1c5 R11: ffff888218f70e2b R12: ffffffff8c0fa030 R13: 0000000000000001 R14: ffffc90001de7a40 R15: ffffffff8c0fa188 FS: 0000000001060880(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000002 CR3: 000000009e6b8000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 --- 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. syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches