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From: syzbot <syzbot+13013adc4a234406c29e@syzkaller.appspotmail.com>
To: b.zolnierkie@samsung.com, daniel.vetter@ffwll.ch,
	dri-devel@lists.freedesktop.org, ghalat@redhat.com,
	gregkh@linuxfoundation.org, linux-fbdev@vger.kernel.org,
	linux-kernel@vger.kernel.org, maarten.lankhorst@linux.intel.com,
	sam@ravnborg.org, syzkaller-bugs@googlegroups.com
Subject: divide error in fbcon_switch
Date: Tue, 03 Dec 2019 20:15:11 +0000	[thread overview]
Message-ID: <00000000000072cb4c0598d25a69@google.com> (raw)

Hello,

syzbot found the following crash on:

HEAD commit:    76bb8b05 Merge tag 'kbuild-v5.5' of git://git.kernel.org/p..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x\x1508781ee00000
kernel config:  https://syzkaller.appspot.com/x/.config?xÝ226651cb0f364b
dashboard link: https://syzkaller.appspot.com/bug?extid\x13013adc4a234406c29e
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x\x132b742ae00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x\x1568f97ee00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+13013adc4a234406c29e@syzkaller.appspotmail.com

divide error: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Workqueue: events console_callback
RIP: 0010:fbcon_update_softback drivers/video/fbdev/core/fbcon.c:378  
[inline]
RIP: 0010:fbcon_switch+0x20d/0x17f0 drivers/video/fbdev/core/fbcon.c:2247
Code: a4 3b 08 4c 89 3d 33 a4 3b 08 38 d0 7c 08 84 d2 0f 85 48 13 00 00 41  
8b 9d 3c 03 00 00 31 d2 bf 05 00 00 00 8b 05 f3 07 13 06 <f7> f3 41 89 c4  
89 c6 e8 67 48 c3 fd 41 83 fc 05 0f 8e d7 0b 00 00
RSP: 0018:ffffc90000d2f9d8 EFLAGS: 00010246
RAX: 0000000000008000 RBX: 0000000000000000 RCX: ffffffff83b1b314
RDX: 0000000000000000 RSI: ffffffff83b1b322 RDI: 0000000000000005
RBP: ffffc90000d2fb68 R08: ffff8880a9a06300 R09: fffffbfff14b0ac8
R10: fffffbfff14b0ac7 R11: ffffffff8a58563b R12: 0000000000000000
R13: ffff88809e21f000 R14: ffff8880a40fc000 R15: ffff8880a3860000
FS:  0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb4a5f9a000 CR3: 00000000a64af000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  redraw_screen+0x2b6/0x7d0 drivers/tty/vt/vt.c:997
  complete_change_console+0x105/0x3a0 drivers/tty/vt/vt_ioctl.c:1264
  change_console+0x19b/0x2c0 drivers/tty/vt/vt_ioctl.c:1389
  console_callback+0x3a1/0x400 drivers/tty/vt/vt.c:2824
  process_one_work+0x9af/0x1740 kernel/workqueue.c:2264
  worker_thread+0x98/0xe40 kernel/workqueue.c:2410
  kthread+0x361/0x430 kernel/kthread.c:255
  ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Modules linked in:
---[ end trace 074c38236abce447 ]---
RIP: 0010:fbcon_update_softback drivers/video/fbdev/core/fbcon.c:378  
[inline]
RIP: 0010:fbcon_switch+0x20d/0x17f0 drivers/video/fbdev/core/fbcon.c:2247
Code: a4 3b 08 4c 89 3d 33 a4 3b 08 38 d0 7c 08 84 d2 0f 85 48 13 00 00 41  
8b 9d 3c 03 00 00 31 d2 bf 05 00 00 00 8b 05 f3 07 13 06 <f7> f3 41 89 c4  
89 c6 e8 67 48 c3 fd 41 83 fc 05 0f 8e d7 0b 00 00
RSP: 0018:ffffc90000d2f9d8 EFLAGS: 00010246
RAX: 0000000000008000 RBX: 0000000000000000 RCX: ffffffff83b1b314
RDX: 0000000000000000 RSI: ffffffff83b1b322 RDI: 0000000000000005
RBP: ffffc90000d2fb68 R08: ffff8880a9a06300 R09: fffffbfff14b0ac8
R10: fffffbfff14b0ac7 R11: ffffffff8a58563b R12: 0000000000000000
R13: ffff88809e21f000 R14: ffff8880a40fc000 R15: ffff8880a3860000
FS:  0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb4a5f9a000 CR3: 00000000a64af000 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

             reply	other threads:[~2019-12-03 20:15 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-03 20:15 syzbot [this message]
2020-07-27 16:45 ` divide error in fbcon_switch syzbot

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