[ OK ] Started Getty on tty2. [ OK ] Started Getty on tty1. [ OK ] Started Serial Getty on ttyS0. [ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.6' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 28.948847] VFS: Found a V7 FS (block size = 512) on device loop0 [ 28.956904] ------------[ cut here ]------------ [ 28.961749] WARNING: CPU: 0 PID: 8003 at fs/inode.c:342 inc_nlink+0x113/0x130 [ 28.969015] Kernel panic - not syncing: panic_on_warn set ... [ 28.969015] [ 28.976567] CPU: 0 PID: 8003 Comm: syz-executor379 Not tainted 4.14.206-syzkaller #0 [ 28.984558] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.993896] Call Trace: [ 28.996469] dump_stack+0x1b2/0x283 [ 29.000175] panic+0x1f9/0x42d [ 29.003364] ? add_taint.cold+0x16/0x16 [ 29.007317] ? inc_nlink+0x113/0x130 [ 29.011015] ? inc_nlink+0x113/0x130 [ 29.014704] __warn.cold+0x20/0x4b [ 29.018220] ? ist_end_non_atomic+0x10/0x10 [ 29.022523] ? inc_nlink+0x113/0x130 [ 29.026225] report_bug+0x208/0x249 [ 29.029966] do_error_trap+0x195/0x2d0 [ 29.033837] ? math_error+0x2d0/0x2d0 [ 29.037680] ? _raw_spin_unlock_irqrestore+0x66/0xe0 [ 29.042788] ? debug_check_no_obj_freed+0x2c0/0x674 [ 29.047784] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 29.052621] invalid_op+0x1b/0x40 [ 29.056054] RIP: 0010:inc_nlink+0x113/0x130 [ 29.060353] RSP: 0018:ffff888091c5fdf0 EFLAGS: 00010297 [ 29.065893] RAX: ffff88809558a540 RBX: ffff88808defc958 RCX: 1ffffffff0f545c1 [ 29.073147] RDX: 0000000000000000 RSI: ffff88808e52d840 RDI: ffff88808defca30 [ 29.080409] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 29.087875] R10: 0000000000000000 R11: 0000000000000000 R12: ffff88808defc9a0 [ 29.095155] R13: ffff88808e52d840 R14: ffffffff87aa2dc0 R15: 0000000000000000 [ 29.102442] sysv_mkdir+0x21/0x120 [ 29.105969] vfs_mkdir+0x463/0x6e0 [ 29.109489] SyS_mkdirat+0x1fd/0x270 [ 29.113208] ? SyS_mknod+0x30/0x30 [ 29.116729] ? __close_fd+0x159/0x230 [ 29.120511] ? do_syscall_64+0x4c/0x640 [ 29.124465] ? SyS_mkdirat+0x270/0x270 [ 29.128337] do_syscall_64+0x1d5/0x640 [ 29.132208] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 29.137375] RIP: 0033:0x444439 [ 29.140542] RSP: 002b:00007ffc956bdd18 EFLAGS: 00000246 ORIG_RAX: 0000000000000053 [ 29.148229] RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000444439 [ 29.155478] RDX: 0000000000400fe0 RSI: 0000000000000023 RDI: 0000000020000080 [ 29.163083] RBP: 00000000006cf018 R08: 00007ffc00000015 R09: 0000000000000000 [ 29.170338] R10: 00007ffc956bdbd0 R11: 0000000000000246 R12: 0000000000402020 [ 29.177607] R13: 00000000004020b0 R14: 0000000000000000 R15: 0000000000000000 [ 29.185879] Kernel Offset: disabled [ 29.189538] Rebooting in 86400 seconds..