bisecting fixing commit since 69b94dd6dcd14d9bfcba35a492f5e27c15cf4d0a
building syzkaller on 340ea5301c27db4a3678f13acc430e04706a0cc6
testing commit 69b94dd6dcd14d9bfcba35a492f5e27c15cf4d0a with gcc (GCC) 8.4.1 20210217
kernel signature: f1a60e47f03cc77531673cd8cf48d7a3c7ced26ace877940ae5e1238b92aa5a3
all runs: crashed: divide error in fbcon_switch
testing current HEAD 670d6552eda8ff0c5f396d3d6f0174237917c66c
testing commit 670d6552eda8ff0c5f396d3d6f0174237917c66c with gcc (GCC) 8.4.1 20210217
kernel signature: d65f982afe1b87cfceb4ad377850ed2f8c963f48b4c1cb277e375db74e549e19
all runs: crashed: divide error in fbcon_init
revisions tested: 2, total time: 21m49.605259807s (build: 15m21.353727582s, test: 6m4.466225436s)
the crash still happens on HEAD
commit msg: Linux 4.14.227
crash: divide error in fbcon_init
IPv6: ADDRCONF(NETDEV_UP): batadv_slave_1: link is not ready
batman_adv: batadv0: Interface activated: batadv_slave_1
IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready
divide error: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 7100 Comm: syz-executor.1 Not tainted 4.14.227-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8881d86dc540 task.stack: ffff8881d8c60000
RIP: 0010:fbcon_init+0x6ee/0x1d50 drivers/video/fbdev/core/fbcon.c:1065
RSP: 0018:ffff8881d8c67868 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8881d7fed500 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 1ffff1103affdb16 RDI: ffff8881d7fed8b4
RBP: ffff8881d8c678f8 R08: ffffffff8a44d100 R09: 0000000000000000
R10: ffff8881d7fed834 R11: ffff8881d7fed838 R12: ffff8881ef329540
R13: 0000000000000006 R14: ffff8881ef100340 R15: ffff8881ef1004f8
FS:  00007f9e4f512700(0000) GS:ffff8881f6600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffdc5565fc8 CR3: 00000001d95cb003 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 visual_init+0x314/0x5d0 drivers/tty/vt/vt.c:746
 vc_allocate drivers/tty/vt/vt.c:802 [inline]
 vc_allocate+0x2d3/0x700 drivers/tty/vt/vt.c:773
 vt_ioctl+0x14a0/0x2090 drivers/tty/vt/vt_ioctl.c:719
 tty_ioctl+0x438/0x1260 drivers/tty/tty_io.c:2661
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x180/0xfb0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x74/0x80 fs/ioctl.c:692
 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x463b49
RSP: 002b:00007f9e4f512188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000055bfa0 RCX: 0000000000463b49
RDX: 0000000020000000 RSI: 000000000000560f RDI: 0000000000000004
RBP: 00000000004ae538 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000055bfa0
R13: 00007ffd46f231bf R14: 00007f9e4f512300 R15: 0000000000022000
Code: 89 d0 48 ba 00 00 00 00 00 fc ff df 48 8b 75 b0 48 c1 ee 03 0f b6 14 16 84 d2 74 09 80 fa 03 0f 8e 6f 10 00 00 31 d2 48 8b 7d a0 <f7> b3 b0 03 00 00 48 89 fa 48 c1 ea 03 41 89 c0 48 b8 00 00 00 
RIP: fbcon_init+0x6ee/0x1d50 drivers/video/fbdev/core/fbcon.c:1065 RSP: ffff8881d8c67868
---[ end trace 1755ee67c87eeda4 ]---