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=-0.9 required=3.0 tests=BAYES_00,FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, UNWANTED_LANGUAGE_BODY 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 1B05BC433E0 for ; Sun, 17 Jan 2021 08:56:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D5C01206D4 for ; Sun, 17 Jan 2021 08:56:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728162AbhAQI4L (ORCPT ); Sun, 17 Jan 2021 03:56:11 -0500 Received: from mail-io1-f72.google.com ([209.85.166.72]:43563 "EHLO mail-io1-f72.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728294AbhAQIyE (ORCPT ); Sun, 17 Jan 2021 03:54:04 -0500 Received: by mail-io1-f72.google.com with SMTP id n18so3776630ioo.10 for ; Sun, 17 Jan 2021 00:53:48 -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:in-reply-to:message-id:subject :from:to; bh=jB63CMEcmJtOeJXwbrg+QK8JaBfOQwDdZLHuAL7bLeE=; b=a5Hdc4N5UrzFhnOd7i/R9cx7rcfzzKM3rfViW+np2nJbk83QMclmZh1DvSt4hb3gZ3 k3bWmEK6GpyRCrGa6KEfva0aX/RayLHTZI7GS9wAK45k+QzS4ebE3DxWCjFqcT/1DL95 vh/v47Fhl0SbsPCZPM4jTudEehSoJAC8FZCZcZ1TI0gT/RQ4EVBV6uesi17H5Zzt7KkL /lc4Jgl9witCp7Fr3gSfEk5tq2HsiJBlociAtXzoS/Yn3/8uoswdq3KMX94Cs9N9b9Tn mD2CiRwd6h4UMpxeX8WtQ3N/C0385Y06iPg9ONKXo3BasIrZ4dimT+8WfMjjT7c1joR3 dmTw== X-Gm-Message-State: AOAM5325T9JEBoHG9AGJ+J1VLae++08/krbcas0GM2i0vMUnEiOGieID 2JZBp5fCpf5PjFOA60bdrdX5CFtWUHqBtCMydGsfLBOcZrCN X-Google-Smtp-Source: ABdhPJweouGIrw+slqM0687JcLjn/DUUC8TDxeOWr6ipObID1P0LywDif7Eo8t3OqmS7tfS+oZoePePlipgPh3nau4OvNFRajgIy MIME-Version: 1.0 X-Received: by 2002:a92:8e0f:: with SMTP id c15mr16383751ild.224.1610873603038; Sun, 17 Jan 2021 00:53:23 -0800 (PST) Date: Sun, 17 Jan 2021 00:53:23 -0800 In-Reply-To: <00000000000091111005b435456e@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000e325f205b914bc4c@google.com> Subject: Re: BUG: unable to handle kernel NULL pointer dereference in fbcon_cursor From: syzbot To: b.zolnierkie@samsung.com, daniel.vetter@ffwll.ch, dri-devel@lists.freedesktop.org, george.kennedy@oracle.com, gregkh@linuxfoundation.org, jirislaby@kernel.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, natechancellor@gmail.com, sam@ravnborg.org, syzkaller-bugs@googlegroups.com, yepeilin.cs@gmail.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org syzbot has found a reproducer for the following issue on: HEAD commit: b3a3cbde Add linux-next specific files for 20210115 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=164096d7500000 kernel config: https://syzkaller.appspot.com/x/.config?x=6ea08dae6aab586f dashboard link: https://syzkaller.appspot.com/bug?extid=b67aaae8d3a927f68d20 compiler: gcc (GCC) 10.1.0-syz 20200507 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15cd8fe0d00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17af5258d00000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+b67aaae8d3a927f68d20@syzkaller.appspotmail.com BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 12267067 P4D 12267067 PUD 11841067 PMD 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 1 PID: 8463 Comm: syz-executor088 Not tainted 5.11.0-rc3-next-20210115-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:0x0 Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. RSP: 0018:ffffc9000132f850 EFLAGS: 00010292 RAX: 0000000000000007 RBX: 0000000000000000 RCX: 0000000000000007 RDX: 0000000000000002 RSI: ffff88814394b000 RDI: ffff888010071000 RBP: ffff888010071000 R08: 0000000000000000 R09: ffffffff83ed87ea R10: 0000000000000003 R11: 0000000000000018 R12: ffff88814394b000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000720 FS: 0000000000db8880(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 0000000020cd8000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: fbcon_cursor+0x50e/0x620 drivers/video/fbdev/core/fbcon.c:1336 hide_cursor+0x85/0x280 drivers/tty/vt/vt.c:907 redraw_screen+0x5b4/0x740 drivers/tty/vt/vt.c:1012 vc_do_resize+0xed8/0x1150 drivers/tty/vt/vt.c:1325 fbcon_set_disp+0x7a8/0xe10 drivers/video/fbdev/core/fbcon.c:1402 con2fb_init_display drivers/video/fbdev/core/fbcon.c:808 [inline] set_con2fb_map+0x7a6/0xf80 drivers/video/fbdev/core/fbcon.c:879 fbcon_set_con2fb_map_ioctl+0x165/0x220 drivers/video/fbdev/core/fbcon.c:3010 do_fb_ioctl+0x5b6/0x690 drivers/video/fbdev/core/fbmem.c:1156 fb_ioctl+0xe7/0x150 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x4402b9 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 7b 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffffae24f88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004402b9 RDX: 0000000020000080 RSI: 0000000000004610 RDI: 0000000000000004 RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8 R10: 00000000004002c8 R11: 0000000000000246 R12: 0000000000401ac0 R13: 0000000000401b50 R14: 0000000000000000 R15: 0000000000000000 Modules linked in: CR2: 0000000000000000 ---[ end trace 5adb9f198fe5efa6 ]--- RIP: 0010:0x0 Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. RSP: 0018:ffffc9000132f850 EFLAGS: 00010292 RAX: 0000000000000007 RBX: 0000000000000000 RCX: 0000000000000007 RDX: 0000000000000002 RSI: ffff88814394b000 RDI: ffff888010071000 RBP: ffff888010071000 R08: 0000000000000000 R09: ffffffff83ed87ea R10: 0000000000000003 R11: 0000000000000018 R12: ffff88814394b000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000720 FS: 0000000000db8880(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 0000000020cd8000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400