bisecting fixing commit since b850307b279cbd12ab8c654d1a3dfe55319cc475
building syzkaller on 6e569755ce2f0efcad474398871ff75693e770fc
testing commit b850307b279cbd12ab8c654d1a3dfe55319cc475 with gcc (GCC) 8.4.1 20210217
kernel signature: 636b06148d59f416988af412d65a543935678ffb32bfca77fbc3e145322e2419
all runs: crashed: general protection fault in do_con_write
testing current HEAD cf256fbcbe347b7d0ff58fe2dfa382a156bd3694
testing commit cf256fbcbe347b7d0ff58fe2dfa382a156bd3694 with gcc (GCC) 8.4.1 20210217
kernel signature: a0d3e4b5d49f2c8780dd9be94dc2fda847a055b29fd8f50e32f844f52832d442
all runs: crashed: divide error in fbcon_init
revisions tested: 2, total time: 29m55.63716975s (build: 22m49.4012079s, test: 6m31.2000623s)
the crash still happens on HEAD
commit msg: Linux 4.14.231
crash: divide error in fbcon_init
IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes 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: 7065 Comm: syz-executor.2 Not tainted 4.14.231-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8881da330500 task.stack: ffff8881cfbe8000
RIP: 0010:fbcon_init+0x6ee/0x1d50 drivers/video/fbdev/core/fbcon.c:1065
RSP: 0018:ffff8881cfbef698 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8881d973ae40 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 1ffff1103b2e763e RDI: ffff8881d973b1f4
RBP: ffff8881cfbef728 R08: ffffffff8a44aac0 R09: 0000000000000000
R10: ffff8881d973b174 R11: ffff8881d973b178 R12: ffff8881ef359540
R13: 0000000000000018 R14: ffff8881ef1c0340 R15: ffff8881ef1c04f8
FS:  00007ffa26542700(0000) GS:ffff8881f6700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2dfe466000 CR3: 00000001da5f6004 CR4: 00000000001606e0
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
 con_install+0x4d/0x4c0 drivers/tty/vt/vt.c:2899
 tty_driver_install_tty drivers/tty/tty_io.c:1225 [inline]
 tty_init_dev drivers/tty/tty_io.c:1338 [inline]
 tty_init_dev+0xdb/0x350 drivers/tty/tty_io.c:1315
 tty_open_by_driver drivers/tty/tty_io.c:1973 [inline]
 tty_open+0x608/0x8e0 drivers/tty/tty_io.c:2021
 chrdev_open+0x1e9/0x5b0 fs/char_dev.c:423
 do_dentry_open+0x3e4/0xde0 fs/open.c:777
 vfs_open+0xfc/0x240 fs/open.c:888
 do_last fs/namei.c:3428 [inline]
 path_openat+0xb6f/0x2760 fs/namei.c:3569
 do_filp_open+0x16b/0x220 fs/namei.c:3603
 do_sys_open+0x1d0/0x350 fs/open.c:1081
 SYSC_openat fs/open.c:1108 [inline]
 SyS_openat+0xf/0x20 fs/open.c:1102
 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x417b94
RSP: 002b:00007ffa26541c50 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000417b94
RDX: 0000000000000002 RSI: 00007ffa26541cf0 RDI: 00000000ffffff9c
RBP: 00007ffa26541cf0 R08: 0000000000000000 R09: 000000000000000e
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002
R13: 00007ffa265426bc R14: 00000000ffffffff R15: 0000000000000003
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: ffff8881cfbef698
---[ end trace 85389dad725b7d77 ]---