[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.201' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program syzkaller login: [ 34.087344] netlink: 4 bytes leftover after parsing attributes in process `syz-executor909'. [ 34.097614] netlink: 4 bytes leftover after parsing attributes in process `syz-executor909'. [ 34.107061] netlink: 4 bytes leftover after parsing attributes in process `syz-executor909'. executing program [ 34.161945] netlink: 4 bytes leftover after parsing attributes in process `syz-executor909'. [ 34.171051] netlink: 4 bytes leftover after parsing attributes in process `syz-executor909'. [ 34.180121] netlink: 4 bytes leftover after parsing attributes in process `syz-executor909'. executing program [ 34.241122] netlink: 4 bytes leftover after parsing attributes in process `syz-executor909'. [ 34.249951] netlink: 4 bytes leftover after parsing attributes in process `syz-executor909'. [ 34.258530] netlink: 4 bytes leftover after parsing attributes in process `syz-executor909'. executing program executing program [ 34.321053] netlink: 4 bytes leftover after parsing attributes in process `syz-executor909'. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 35.818492] refcount_t: underflow; use-after-free. [ 35.824315] ------------[ cut here ]------------ [ 35.829099] WARNING: CPU: 0 PID: 8187 at lib/refcount.c:281 refcount_dec_not_one.cold+0x18/0x25 [ 35.838104] Kernel panic - not syncing: kernel: panic_on_warn set ... [ 35.838104] [ 35.846161] CPU: 0 PID: 8187 Comm: systemd-udevd Not tainted 4.14.307-syzkaller #0 [ 35.853853] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023 [ 35.864469] Call Trace: [ 35.867067] dump_stack+0x1b2/0x281 [ 35.870688] panic+0x21d/0x451 [ 35.873884] ? add_taint.cold+0x16/0x16 [ 35.877866] ? log_store.cold+0x16/0x16 [ 35.881852] ? refcount_dec_not_one.cold+0x18/0x25 [ 35.886787] check_panic_on_warn.cold+0x19/0x35 [ 35.891449] __warn+0xdf/0x1e0 [ 35.894630] ? ist_end_non_atomic+0x10/0x10 [ 35.898943] ? refcount_dec_not_one.cold+0x18/0x25 [ 35.903859] report_bug+0x208/0x250 [ 35.907483] do_error_trap+0x195/0x2d0 [ 35.911358] ? math_error+0x2d0/0x2d0 [ 35.915154] ? ___preempt_schedule+0x16/0x18 [ 35.919584] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 35.924421] invalid_op+0x1b/0x40 [ 35.927864] RIP: 0010:refcount_dec_not_one.cold+0x18/0x25 [ 35.933380] RSP: 0018:ffff8880b06dfc38 EFLAGS: 00010286 [ 35.938750] RAX: 0000000000000026 RBX: 0000000000000000 RCX: 0000000000000000 [ 35.946022] RDX: 0000000000000000 RSI: ffffffff878bd360 RDI: ffffed10160dbf7d [ 35.953276] RBP: ffff8880992ae698 R08: 0000000000000026 R09: 0000000000000000 [ 35.960532] R10: 0000000000000000 R11: 0000000000000000 R12: 00000000ffffffff [ 35.967820] R13: 0000000000000000 R14: ffffed1011911e86 R15: ffff8880992ae6a8 [ 35.975097] ? refcount_dec_not_one.cold+0x18/0x25 [ 35.980022] ? trace_hardirqs_on_caller+0x3a8/0x580 [ 35.985039] refcount_dec_and_mutex_lock+0x1a/0x60 [ 35.989974] nbd_config_put+0x442/0x6c0 [ 35.993946] nbd_release+0xdf/0x150 [ 35.997662] ? nbd_ioctl+0xad0/0xad0 [ 36.001466] __blkdev_put+0x5aa/0x800 [ 36.005260] ? revalidate_disk+0x1f0/0x1f0 [ 36.009492] ? locks_remove_file+0x2cd/0x420 [ 36.013896] ? blkdev_put+0x75/0x4c0 [ 36.017614] ? blkdev_put+0x4c0/0x4c0 [ 36.021498] blkdev_close+0x86/0xb0 [ 36.025132] __fput+0x25f/0x7a0 [ 36.028416] task_work_run+0x11f/0x190 [ 36.032302] exit_to_usermode_loop+0x1ad/0x200 [ 36.036873] do_syscall_64+0x4a3/0x640 [ 36.040758] entry_SYSCALL_64_after_hwframe+0x5e/0xd3 [ 36.045934] RIP: 0033:0x7f87e518b270 [ 36.049731] RSP: 002b:00007fff4f2eeaa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 36.057474] RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007f87e518b270 [ 36.064756] RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007 [ 36.072019] RBP: 00007f87e6045710 R08: 0000000000000045 R09: 0000000000000018 [ 36.079290] R10: 000055bb0a9c6b28 R11: 0000000000000246 R12: 0000000000000000 [ 36.086547] R13: 000055bb0a9c4880 R14: 0000000000000003 R15: 000000000000000e [ 36.094244] Kernel Offset: disabled [ 36.097929] Rebooting in 86400 seconds..