[ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.155' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 35.588637] ================================================================== [ 35.588661] BUG: KASAN: slab-out-of-bounds in bit_putcs+0xb3a/0xcd0 [ 35.588666] Read of size 1 at addr ffff8880951211ff by task syz-executor436/6337 [ 35.588667] [ 35.588672] CPU: 1 PID: 6337 Comm: syz-executor436 Not tainted 4.14.175-syzkaller #0 [ 35.588675] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 35.588677] Call Trace: [ 35.588686] dump_stack+0x13e/0x194 [ 35.588692] ? bit_putcs+0xb3a/0xcd0 [ 35.588700] print_address_description.cold+0x7c/0x1e2 [ 35.588705] ? bit_putcs+0xb3a/0xcd0 [ 35.588709] kasan_report.cold+0xa9/0x2ae [ 35.588715] bit_putcs+0xb3a/0xcd0 [ 35.588726] ? update_attr.isra.0+0x160/0x160 [ 35.588733] ? fb_get_color_depth+0x5a/0x70 [ 35.588740] ? update_attr.isra.0+0x160/0x160 [ 35.588743] fbcon_putcs+0x3c6/0x490 [ 35.588752] do_update_region+0x34b/0x5b0 [ 35.588759] ? con_get_trans_old+0x200/0x200 [ 35.588767] redraw_screen+0x561/0x770 [ 35.588772] ? con_flush_chars+0x80/0x80 [ 35.588779] vc_do_resize+0xbe0/0xde0 [ 35.588788] ? vt_console_print+0xec0/0xec0 [ 35.588796] vt_ioctl+0x1a64/0x1f20 [ 35.588801] ? complete_change_console+0x350/0x350 [ 35.588806] ? avc_ss_reset+0x100/0x100 [ 35.588811] ? save_stack+0x32/0xa0 [ 35.588815] ? kasan_slab_free+0x75/0xc0 [ 35.588818] ? kmem_cache_free+0x7c/0x2b0 [ 35.588823] ? putname+0xcd/0x110 [ 35.588828] ? do_sys_open+0x1f9/0x3f0 [ 35.588834] ? do_syscall_64+0x1d5/0x640 [ 35.588839] ? entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 35.588845] ? tty_jobctrl_ioctl+0x3b/0xbf0 [ 35.588849] ? complete_change_console+0x350/0x350 [ 35.588861] tty_ioctl+0x6c5/0x1220 [ 35.588866] ? tty_vhangup+0x30/0x30 [ 35.588873] ? lock_acquire+0x170/0x3f0 [ 35.588877] ? lock_downgrade+0x6e0/0x6e0 [ 35.588887] ? tty_vhangup+0x30/0x30 [ 35.588893] do_vfs_ioctl+0x75a/0xfe0 [ 35.588899] ? selinux_file_mprotect+0x5c0/0x5c0 [ 35.588904] ? ioctl_preallocate+0x1a0/0x1a0 [ 35.588911] ? rcu_read_lock_sched_held+0x10a/0x130 [ 35.588914] ? kmem_cache_free+0x23a/0x2b0 [ 35.588919] ? putname+0xcd/0x110 [ 35.588927] ? security_file_ioctl+0x76/0xb0 [ 35.588931] ? security_file_ioctl+0x83/0xb0 [ 35.588936] SyS_ioctl+0x7f/0xb0 [ 35.588940] ? do_vfs_ioctl+0xfe0/0xfe0 [ 35.588945] do_syscall_64+0x1d5/0x640 [ 35.588952] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 35.588957] RIP: 0033:0x440219 [ 35.588960] RSP: 002b:00007fffab232798 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 35.588966] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440219 [ 35.588969] RDX: 0000000020000040 RSI: 000000000000560a RDI: 0000000000000004 [ 35.588972] RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8 [ 35.588981] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401b00 [ 35.588984] R13: 0000000000401b90 R14: 0000000000000000 R15: 0000000000000000 [ 35.588991] [ 35.588994] Allocated by task 6337: [ 35.588998] save_stack+0x32/0xa0 [ 35.589001] kasan_kmalloc+0xbf/0xe0 [ 35.589004] __kmalloc+0x15b/0x7c0 [ 35.589008] fbcon_set_font+0x2f8/0x7c0 [ 35.589012] con_font_op+0xb73/0xf70 [ 35.589014] vt_ioctl+0x736/0x1f20 [ 35.589018] tty_ioctl+0x6c5/0x1220 [ 35.589021] do_vfs_ioctl+0x75a/0xfe0 [ 35.589025] SyS_ioctl+0x7f/0xb0 [ 35.589028] do_syscall_64+0x1d5/0x640 [ 35.589032] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 35.589033] [ 35.589035] Freed by task 5298: [ 35.589039] save_stack+0x32/0xa0 [ 35.589042] kasan_slab_free+0x75/0xc0 [ 35.589045] kfree+0xcb/0x260 [ 35.589050] load_elf_binary+0x1bd6/0x46b0 [ 35.589055] search_binary_handler+0x139/0x6c0 [ 35.589059] do_execveat_common.isra.0+0xf32/0x1c70 [ 35.589062] SyS_execve+0x34/0x40 [ 35.589066] do_syscall_64+0x1d5/0x640 [ 35.589069] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 35.589071] [ 35.589074] The buggy address belongs to the object at ffff8880951210c0 [ 35.589074] which belongs to the cache kmalloc-512 of size 512 [ 35.589077] The buggy address is located 319 bytes inside of [ 35.589077] 512-byte region [ffff8880951210c0, ffff8880951212c0) [ 35.589079] The buggy address belongs to the page: [ 35.589083] page:ffffea0002544840 count:1 mapcount:0 mapping:ffff8880951210c0 index:0xffff888095121340 [ 35.589088] flags: 0xfffe0000000100(slab) [ 35.589094] raw: 00fffe0000000100 ffff8880951210c0 ffff888095121340 0000000100000003 [ 35.589099] raw: ffffea00025af920 ffffea0002548c60 ffff88812fe56940 0000000000000000 [ 35.589101] page dumped because: kasan: bad access detected [ 35.589102] [ 35.589103] Memory state around the buggy address: [ 35.589107] ffff888095121080: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 [ 35.589110] ffff888095121100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 35.589113] >ffff888095121180: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc [ 35.589115] ^ [ 35.589119] ffff888095121200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 35.589122] ffff888095121280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 35.589123] ================================================================== [ 35.589125] Disabling lock debugging due to kernel taint [ 35.589150] Kernel panic - not syncing: panic_on_warn set ... [ 35.589150] [ 35.589154] CPU: 1 PID: 6337 Comm: syz-executor436 Tainted: G B 4.14.175-syzkaller #0 [ 35.589156] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 35.589157] Call Trace: [ 35.589162] dump_stack+0x13e/0x194 [ 35.589167] panic+0x1f9/0x42d [ 35.589170] ? add_taint.cold+0x16/0x16 [ 35.589176] ? bit_putcs+0xb3a/0xcd0 [ 35.589180] kasan_end_report+0x43/0x49 [ 35.589183] kasan_report.cold+0x12f/0x2ae [ 35.589188] bit_putcs+0xb3a/0xcd0 [ 35.589195] ? update_attr.isra.0+0x160/0x160 [ 35.589200] ? fb_get_color_depth+0x5a/0x70 [ 35.589205] ? update_attr.isra.0+0x160/0x160 [ 35.589208] fbcon_putcs+0x3c6/0x490 [ 35.589213] do_update_region+0x34b/0x5b0 [ 35.589218] ? con_get_trans_old+0x200/0x200 [ 35.589224] redraw_screen+0x561/0x770 [ 35.589228] ? con_flush_chars+0x80/0x80 [ 35.589233] vc_do_resize+0xbe0/0xde0 [ 35.589239] ? vt_console_print+0xec0/0xec0 [ 35.589244] vt_ioctl+0x1a64/0x1f20 [ 35.589248] ? complete_change_console+0x350/0x350 [ 35.589251] ? avc_ss_reset+0x100/0x100 [ 35.589255] ? save_stack+0x32/0xa0 [ 35.589258] ? kasan_slab_free+0x75/0xc0 [ 35.589261] ? kmem_cache_free+0x7c/0x2b0 [ 35.589264] ? putname+0xcd/0x110 [ 35.589267] ? do_sys_open+0x1f9/0x3f0 [ 35.589271] ? do_syscall_64+0x1d5/0x640 [ 35.589274] ? entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 35.589278] ? tty_jobctrl_ioctl+0x3b/0xbf0 [ 35.589281] ? complete_change_console+0x350/0x350 [ 35.589285] tty_ioctl+0x6c5/0x1220 [ 35.589289] ? tty_vhangup+0x30/0x30 [ 35.589293] ? lock_acquire+0x170/0x3f0 [ 35.589297] ? lock_downgrade+0x6e0/0x6e0 [ 35.589304] ? tty_vhangup+0x30/0x30 [ 35.589308] do_vfs_ioctl+0x75a/0xfe0 [ 35.589312] ? selinux_file_mprotect+0x5c0/0x5c0 [ 35.589316] ? ioctl_preallocate+0x1a0/0x1a0 [ 35.589320] ? rcu_read_lock_sched_held+0x10a/0x130 [ 35.589323] ? kmem_cache_free+0x23a/0x2b0 [ 35.589326] ? putname+0xcd/0x110 [ 35.589331] ? security_file_ioctl+0x76/0xb0 [ 35.589335] ? security_file_ioctl+0x83/0xb0 [ 35.589339] SyS_ioctl+0x7f/0xb0 [ 35.589342] ? do_vfs_ioctl+0xfe0/0xfe0 [ 35.589346] do_syscall_64+0x1d5/0x640 [ 35.589351] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 35.589354] RIP: 0033:0x440219 [ 35.589356] RSP: 002b:00007fffab232798 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 35.589360] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440219 [ 35.589362] RDX: 0000000020000040 RSI: 000000000000560a RDI: 0000000000000004 [ 35.589364] RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8 [ 35.589367] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401b00 [ 35.589369] R13: 0000000000401b90 R14: 0000000000000000 R15: 0000000000000000 [ 35.590853] Kernel Offset: disabled [ 36.380749] Rebooting in 86400 seconds..