syzbot


divide error in fbcon_switch

Status: closed as dup on 2020/07/27 22:47
Subsystems: fbdev
[Documentation on labels]
Reported-by: syzbot+13013adc4a234406c29e@syzkaller.appspotmail.com
First crash: 1631d, last: 1425d
Cause bisection: the issue happens on the oldest tested release (bisect log)
Crash: no output from test machine (log)
Repro: C syz .config
  
Fix bisection: fixed by (bisect log) :
commit ce684552a266cb1c7cc2f7e623f38567adec6653
Author: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Sun Jul 12 11:10:12 2020 +0000

  vt: Reject zero-sized screen buffer size.

  
Duplicate of
Title Repro Cause bisect Fix bisect Count Last Reported
general protection fault in do_con_write C done 10703 1395d 1630d
Discussions (1)
Title Replies (including bot) Last reply
divide error in fbcon_switch 0 (2) 2020/07/27 16:45
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 divide error in fbcon_switch C error 282 635d 1631d 0/1 upstream: reported C repro on 2019/12/03 01:21
linux-4.19 divide error in fbcon_switch C done 259 1392d 1631d 1/1 fixed on 2020/09/01 18:34

Sample crash report:
divide error: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 3008 Comm: kworker/0:2 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:ffffc900083f79d8 EFLAGS: 00010246
RAX: 0000000000008000 RBX: 0000000000000000 RCX: ffffffff83b1b314
RDX: 0000000000000000 RSI: ffffffff83b1b322 RDI: 0000000000000005
RBP: ffffc900083f7b68 R08: ffff88809f2c02c0 R09: fffffbfff14b0ac8
R10: fffffbfff14b0ac7 R11: ffffffff8a58563b R12: 0000000000000000
R13: ffff888097ba8000 R14: ffff88821910f000 R15: ffff8880a3e90000
FS:  0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffb67643000 CR3: 000000009fe78000 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 1b376dfbbd93035d ]---
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:ffffc900083f79d8 EFLAGS: 00010246
RAX: 0000000000008000 RBX: 0000000000000000 RCX: ffffffff83b1b314
RDX: 0000000000000000 RSI: ffffffff83b1b322 RDI: 0000000000000005
RBP: ffffc900083f7b68 R08: ffff88809f2c02c0 R09: fffffbfff14b0ac8
R10: fffffbfff14b0ac7 R11: ffffffff8a58563b R12: 0000000000000000
R13: ffff888097ba8000 R14: ffff88821910f000 R15: ffff8880a3e90000
FS:  0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffb67643000 CR3: 000000009fe78000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (326):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/12/03 20:36 upstream 76bb8b05960c ae13a849 .config console log report syz C ci-upstream-kasan-gce-root
2019/12/03 16:46 upstream 76bb8b05960c ab342da3 .config console log report syz C ci-upstream-kasan-gce-selinux-root
2020/06/26 02:26 upstream 7ae77150d94d aea82c00 .config console log report ci-upstream-kasan-gce-selinux-root
2020/06/25 23:32 upstream 7ae77150d94d f9147b08 .config console log report ci-upstream-kasan-gce-selinux-root
2020/06/25 17:32 upstream 7ae77150d94d c7b4497a .config console log report ci-upstream-kasan-gce-selinux-root
2020/06/25 11:16 upstream 7ae77150d94d 54566aff .config console log report ci-upstream-kasan-gce-selinux-root
2020/06/25 09:50 upstream 7ae77150d94d 54566aff .config console log report ci-upstream-kasan-gce-smack-root
2020/06/25 07:40 upstream 7ae77150d94d 54566aff .config console log report ci-upstream-kasan-gce
2020/06/25 06:18 upstream 7ae77150d94d 54566aff .config console log report ci-upstream-kasan-gce-selinux-root
2020/06/25 01:59 upstream 7ae77150d94d 54566aff .config console log report ci-upstream-kasan-gce-root
2020/06/24 22:04 upstream 7ae77150d94d 54566aff .config console log report ci-upstream-kasan-gce
2020/06/24 18:38 upstream 7ae77150d94d 54566aff .config console log report ci-upstream-kasan-gce-selinux-root
2020/06/24 06:18 upstream 7ae77150d94d 54566aff .config console log report ci-upstream-kasan-gce-root
2020/06/23 07:17 upstream 7ae77150d94d 1afe1535 .config console log report ci-upstream-kasan-gce-selinux-root
2020/06/20 02:18 upstream 7ae77150d94d 81abc331 .config console log report ci-upstream-kasan-gce-smack-root
2020/06/19 16:32 upstream 7ae77150d94d bc258b50 .config console log report ci-upstream-kasan-gce-root
2020/06/19 12:33 upstream 7ae77150d94d bc258b50 .config console log report ci-upstream-kasan-gce-root
2020/06/19 04:00 upstream 7ae77150d94d bc258b50 .config console log report ci-upstream-kasan-gce-smack-root
2020/06/19 00:55 upstream 7ae77150d94d bc258b50 .config console log report ci-upstream-kasan-gce-smack-root
2020/06/18 12:20 upstream 7ae77150d94d d45a4d69 .config console log report ci-upstream-kasan-gce-root
2020/06/18 07:16 upstream 7ae77150d94d d45a4d69 .config console log report ci-upstream-kasan-gce-root
2020/06/17 14:00 upstream 7ae77150d94d b9f3810b .config console log report ci-upstream-kasan-gce-root
2020/06/17 08:56 upstream 7ae77150d94d b9f3810b .config console log report ci-upstream-kasan-gce-root
2020/06/17 04:04 upstream 7ae77150d94d 559fbe2d .config console log report ci-upstream-kasan-gce-root
2020/06/17 01:42 upstream 7ae77150d94d 559fbe2d .config console log report ci-upstream-kasan-gce-root
2020/06/16 19:29 upstream 7ae77150d94d 559fbe2d .config console log report ci-upstream-kasan-gce-selinux-root
2020/06/16 08:03 upstream 7ae77150d94d baca2611 .config console log report ci-upstream-kasan-gce-root
2020/06/15 19:09 upstream 7ae77150d94d baca2611 .config console log report ci-upstream-kasan-gce-root
2020/06/15 16:33 upstream 7ae77150d94d 8e3ab941 .config console log report ci-upstream-kasan-gce-smack-root
2020/06/15 13:38 upstream 7ae77150d94d 8e3ab941 .config console log report ci-upstream-kasan-gce-smack-root
2020/06/14 23:31 upstream 7ae77150d94d 2a22c77a .config console log report ci-upstream-kasan-gce-root
2020/06/14 20:02 upstream 7ae77150d94d 2a22c77a .config console log report ci-upstream-kasan-gce-smack-root
2020/06/11 19:13 upstream 7ae77150d94d 3ab7a05a .config console log report ci-upstream-kasan-gce-selinux-root
2020/06/10 15:59 upstream 7ae77150d94d a6f7998d .config console log report ci-upstream-kasan-gce-smack-root
2020/06/10 04:51 upstream 7ae77150d94d 860c4de9 .config console log report ci-upstream-kasan-gce-root
2020/06/10 03:42 upstream 7ae77150d94d 860c4de9 .config console log report ci-upstream-kasan-gce-root
2020/06/10 01:32 upstream 7ae77150d94d 860c4de9 .config console log report ci-upstream-kasan-gce-smack-root
2020/06/09 15:26 upstream 7ae77150d94d 092934c1 .config console log report ci-upstream-kasan-gce-root
2020/06/09 12:43 upstream 7ae77150d94d 0d60b78a .config console log report ci-upstream-kasan-gce-root
2020/06/09 03:09 upstream 7ae77150d94d 0d60b78a .config console log report ci-upstream-kasan-gce-smack-root
2020/06/09 00:34 upstream 7ae77150d94d 7604bb03 .config console log report ci-upstream-kasan-gce-selinux-root
2020/06/08 15:11 upstream 7ae77150d94d 7604bb03 .config console log report ci-upstream-kasan-gce-root
2020/06/08 00:49 upstream 7ae77150d94d 2c2b926c .config console log report ci-upstream-kasan-gce-selinux-root
2020/06/07 11:18 upstream 7ae77150d94d 2c2b926c .config console log report ci-upstream-kasan-gce-smack-root
2020/06/06 07:50 upstream 7ae77150d94d e6b89e4e .config console log report ci-upstream-kasan-gce-smack-root
2020/06/01 23:03 upstream 9bf9511e3d9f a0331e89 .config console log report ci-upstream-kasan-gce-selinux-root
2020/05/29 00:01 upstream 75caf310d16c 0d951763 .config console log report ci-upstream-kasan-gce-root
2020/05/28 22:59 upstream 75caf310d16c 0d951763 .config console log report ci-upstream-kasan-gce-root
2020/06/24 23:57 upstream 7ae77150d94d 54566aff .config console log report ci-upstream-kasan-gce-386
2020/06/18 06:12 upstream 7ae77150d94d d45a4d69 .config console log report ci-upstream-kasan-gce-386
2020/05/23 05:16 linux-next c11d28ab4a69 9682898d .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.