bisecting fixing commit since 69b94dd6dcd14d9bfcba35a492f5e27c15cf4d0a
building syzkaller on 340ea5301c27db4a3678f13acc430e04706a0cc6
testing commit 69b94dd6dcd14d9bfcba35a492f5e27c15cf4d0a with gcc (GCC) 8.1.0
kernel signature: bb3032214de17920f308b284c362143635ed5776d9c632acd48b4837838f7104
all runs: crashed: divide error in fbcon_switch
testing current HEAD 5b7a52cd2eef952cee8a72512ef370bcdef46636
testing commit 5b7a52cd2eef952cee8a72512ef370bcdef46636 with gcc (GCC) 8.1.0
kernel signature: 673cd7c1985cd166d374f272ff35737849a2b1122b15237748fbd2d9fe0963ad
all runs: crashed: divide error in fbcon_init
revisions tested: 2, total time: 22m34.439864604s (build: 16m5.528576386s, test: 5m53.885575692s)
the crash still happens on HEAD
commit msg: Linux 4.14.202
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: 1 PID: 7861 Comm: syz-executor.4 Not tainted 4.14.202-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8880a03ec400 task.stack: ffff88809fc28000
RIP: 0010:fbcon_init+0x6ee/0x1d50 drivers/video/fbdev/core/fbcon.c:1065
RSP: 0018:ffff88809fc2f868 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88809db38a80 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 1ffff11013b671c6 RDI: ffff88809db38e34
RBP: ffff88809fc2f8f8 R08: ffffffff8a44b100 R09: 0000000000000000
R10: ffff88809db38db4 R11: ffff88809db38db8 R12: ffff8880b1aeed00
R13: 0000000000000006 R14: ffff8880b1b03d00 R15: ffff8880b1b03eb8
FS:  00007fd6547fa700(0000) GS:ffff8880ba900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f96700390c8 CR3: 00000000a0188000 CR4: 00000000001406e0
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+0x2d3/0x700 drivers/tty/vt/vt.c:802
 vt_ioctl+0x15c8/0x2250 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: 0033:0x45c1f9
RSP: 002b:00007fd6547f9c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000017a00 RCX: 000000000045c1f9
RDX: 0000000020000000 RSI: 000000000000560f RDI: 0000000000000004
RBP: 000000000078bfe0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bfac
R13: 00007ffdc605144f R14: 00007fd6547fa9c0 R15: 000000000078bfac
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: ffff88809fc2f868
---[ end trace 8271e40c20145422 ]---