bisecting fixing commit since 69b94dd6dcd14d9bfcba35a492f5e27c15cf4d0a
building syzkaller on 340ea5301c27db4a3678f13acc430e04706a0cc6
testing commit 69b94dd6dcd14d9bfcba35a492f5e27c15cf4d0a with gcc (GCC) 8.1.0
kernel signature: 46b0eb01ec5e6ea10cfc60ff3308e46ebef78d96f61707d7df53518939ed253a
all runs: crashed: divide error in fbcon_switch
testing current HEAD 87335852c5d9ec629f80bb2257b9a9945962b719
testing commit 87335852c5d9ec629f80bb2257b9a9945962b719 with gcc (GCC) 8.1.0
kernel signature: d79e9ebe9db20860c45f9a1b9afba810394607bfc2acadc961d03cb5a89ca766
all runs: crashed: divide error in fbcon_init
revisions tested: 2, total time: 26m12.203041498s (build: 20m8.18373576s, test: 5m32.498548665s)
the crash still happens on HEAD
commit msg: Linux 4.14.209
crash: divide error in fbcon_init
device veth0_macvtap entered promiscuous mode
IPv6: ADDRCONF(NETDEV_UP): macvtap0: link is not ready
device veth1_macvtap entered promiscuous mode
IPv6: ADDRCONF(NETDEV_UP): macsec0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth0_to_batadv: link is not ready
divide error: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 1 PID: 7826 Comm: syz-executor.4 Not tainted 4.14.209-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff88809fbf4180 task.stack: ffff8880a00d0000
RIP: 0010:fbcon_init+0x6ee/0x1d50 drivers/video/fbdev/core/fbcon.c:1065
RSP: 0018:ffff8880a00d7868 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8880a6e4d2c0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 1ffff11014dc9ace RDI: ffff8880a6e4d674
RBP: ffff8880a00d78f8 R08: ffffffff8a44a0c0 R09: 0000000000000000
R10: ffff8880a6e4d5f4 R11: ffff8880a6e4d5f8 R12: ffff8880b1a9e5c0
R13: 0000000000000006 R14: ffff888238de75c0 R15: ffff888238de7778
FS:  00007f0051396700(0000) GS:ffff8880ba900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1408a03018 CR3: 00000000a0be8000 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+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: 0033:0x45c1f9
RSP: 002b:00007f0051395c78 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: 00007ffcb8213e0f R14: 00007f00513969c0 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: ffff8880a00d7868
---[ end trace b9470404b6fff29d ]---