[  OK  ] Started OpenBSD Secure Shell server.
[  OK  ] Listening on Load/Save RF Kill Switch Status /dev/rfkill Watch.
[  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...
[  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 '10.128.1.126' (ECDSA) to the list of known hosts.
syzkaller login: [   27.569255] IPVS: ftp: loaded support on port[0] = 21
executing program
[   27.688056] BTRFS: device fsid 24c7a497-3402-47dd-bef8-82358f5f30e0 devid 1 transid 8 /dev/loop0
[   27.710099] BTRFS info (device loop0): using free space tree
[   27.715974] BTRFS info (device loop0): has skinny extents
[   27.761419] FAULT_INJECTION: forcing a failure.
[   27.761419] name failslab, interval 1, probability 0, space 0, times 1
[   27.772754] CPU: 1 PID: 7988 Comm: syz-executor300 Not tainted 4.14.302-syzkaller #0
[   27.780627] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
[   27.789970] Call Trace:
[   27.792548]  dump_stack+0x1b2/0x281
[   27.796170]  should_fail.cold+0x10a/0x149
[   27.800301]  should_failslab+0xd6/0x130
[   27.804260]  kmem_cache_alloc+0x28e/0x3c0
[   27.808418]  btrfs_alloc_tree_block+0xcfa/0x1410
[   27.813160]  ? btrfs_reserve_extent+0x3b0/0x3b0
[   27.817808]  ? __lock_acquire+0x2190/0x3f20
[   27.822105]  ? memcpy+0x35/0x50
[   27.825363]  ? read_extent_buffer+0x102/0x150
[   27.829835]  __btrfs_cow_block+0x367/0xfd0
[   27.834049]  ? btrfs_set_lock_blocking_rw+0x266/0x2f0
[   27.839231]  ? update_ref_for_cow+0x980/0x980
[   27.843713]  ? btrfs_tree_read_unlock_blocking+0x210/0x210
[   27.849314]  btrfs_cow_block+0x207/0x6d0
[   27.853361]  ? btrfs_set_path_blocking+0x39/0x110
[   27.858187]  btrfs_search_slot+0x546/0x1c20
[   27.862494]  ? split_leaf+0x14a0/0x14a0
[   27.866448]  ? join_transaction+0x181/0xcc0
[   27.870746]  ? btrfs_record_root_in_trans+0x106/0x150
[   27.875917]  btrfs_insert_empty_items+0xaf/0x160
[   27.880653]  insert_balance_item.isra.0+0xef/0x13f0
[   27.885649]  ? trace_hardirqs_on+0x10/0x10
[   27.889859]  ? __cancel_balance+0x2d0/0x2d0
[   27.894157]  ? _raw_spin_unlock_irqrestore+0x79/0xe0
[   27.899240]  ? trace_hardirqs_on_caller+0x3a8/0x580
[   27.904235]  ? btrfs_dev_replace_unlock+0x2e/0x50
[   27.909054]  ? btrfs_ioctl_balance+0x5e6/0x730
[   27.913613]  ? mark_held_locks+0xa6/0xf0
[   27.917649]  ? btrfs_balance+0x148f/0x39b0
[   27.921861]  ? btrfs_get_num_tolerated_disk_barrier_failures+0xd7/0x150
[   27.928587]  btrfs_balance+0xa50/0x39b0
[   27.932538]  ? btrfs_ioctl_balance+0x24e/0x730
[   27.937097]  ? btrfs_ioctl_balance+0x24e/0x730
[   27.941655]  ? __mutex_lock+0x360/0x1310
[   27.945691]  ? __read_once_size_nocheck.constprop.0+0x10/0x10
[   27.951548]  ? trace_hardirqs_on+0x10/0x10
[   27.955760]  ? ima_rdwr_violation_check+0x3a0/0x3a0
[   27.960749]  ? btrfs_ioctl_balance+0x24e/0x730
[   27.965309]  ? fs_reclaim_release+0xd0/0x110
[   27.969694]  ? btrfs_shrink_device+0xdc0/0xdc0
[   27.974254]  ? btrfs_ioctl_balance+0x425/0x730
[   27.978818]  ? rcu_lockdep_current_cpu_online+0xed/0x140
[   27.984244]  ? rcu_read_lock_sched_held+0x16c/0x1d0
[   27.989246]  ? kmem_cache_alloc_trace+0x36c/0x3d0
[   27.994066]  btrfs_ioctl_balance+0x5e6/0x730
[   27.998450]  btrfs_ioctl+0xddf/0x5b20
[   28.002226]  ? _kstrtoull+0x1f2/0x450
[   28.006004]  ? btrfs_ioctl_get_supported_features+0x40/0x40
[   28.011689]  ? get_pid_task+0x91/0x130
[   28.015581]  ? lock_downgrade+0x740/0x740
[   28.019711]  ? get_pid_task+0xb8/0x130
[   28.023660]  ? proc_fail_nth_write+0x7b/0x180
[   28.028132]  ? proc_tgid_io_accounting+0x7a0/0x7a0
[   28.033038]  ? fsnotify+0x974/0x11b0
[   28.036745]  ? proc_tgid_io_accounting+0x7a0/0x7a0
[   28.041655]  ? debug_check_no_obj_freed+0x2c0/0x680
[   28.046647]  ? btrfs_ioctl_get_supported_features+0x40/0x40
[   28.052334]  do_vfs_ioctl+0x75a/0xff0
[   28.056118]  ? ioctl_preallocate+0x1a0/0x1a0
[   28.060506]  ? vfs_write+0x319/0x4d0
[   28.064198]  ? SyS_write+0x14d/0x210
[   28.067892]  ? security_file_ioctl+0x83/0xb0
[   28.072278]  SyS_ioctl+0x7f/0xb0
[   28.075619]  ? do_vfs_ioctl+0xff0/0xff0
[   28.079572]  do_syscall_64+0x1d5/0x640
[   28.083439]  entry_SYSCALL_64_after_hwframe+0x5e/0xd3
[   28.088691] RIP: 0033:0x7f5fdafe61e9
[   28.092408] RSP: 002b:00007ffc0bcbc0f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[   28.100090] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f5fdafe61e9
[   28.107335] RDX: 0000000000000000 RSI: 00000000c4009420 RDI: 0000000000000004
[   28.114582] RBP: 00007ffc0bcbc110 R08: 0000000000000001 R09: 00007ffc0bcbc298
[   28.121828] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005
[   28.129073] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[   28.158092] ------------[ cut here ]------------
[   28.162933] WARNING: CPU: 1 PID: 7988 at fs/btrfs/extent-tree.c:10028 btrfs_free_block_groups+0x713/0xc50
[   28.172796] Kernel panic - not syncing: panic_on_warn set ...
[   28.172796] 
[   28.180138] CPU: 1 PID: 7988 Comm: syz-executor300 Not tainted 4.14.302-syzkaller #0
[   28.187996] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
[   28.197327] Call Trace:
[   28.199898]  dump_stack+0x1b2/0x281
[   28.203504]  panic+0x1f9/0x42d
[   28.206674]  ? add_taint.cold+0x16/0x16
[   28.210629]  ? btrfs_free_block_groups+0x713/0xc50
[   28.215540]  ? btrfs_free_block_groups+0x713/0xc50
[   28.220449]  __warn.cold+0x20/0x44
[   28.223972]  ? ist_end_non_atomic+0x10/0x10
[   28.228282]  ? btrfs_free_block_groups+0x713/0xc50
[   28.233189]  report_bug+0x208/0x250
[   28.236797]  do_error_trap+0x195/0x2d0
[   28.240667]  ? math_error+0x2d0/0x2d0
[   28.244451]  ? lock_acquire+0x170/0x3f0
[   28.248407]  ? space_info_add_old_bytes+0x26/0x7e0
[   28.253319]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   28.258143]  invalid_op+0x1b/0x40
[   28.261579] RIP: 0010:btrfs_free_block_groups+0x713/0xc50
[   28.267091] RSP: 0018:ffff8880b360fb10 EFLAGS: 00010297
[   28.272432] RAX: ffff8880b4f08300 RBX: 0000000000000000 RCX: ffffed10130d0ddb
[   28.279683] RDX: 0000000000000000 RSI: ffff888098686ed8 RDI: ffff8880b325d258
[   28.286931] RBP: ffff888098685b80 R08: ffffffff8ba60b0c R09: 0000000000000001
[   28.294186] R10: 0000000000000000 R11: ffff8880b4f08300 R12: ffff8880b325d2e8
[   28.301433] R13: dffffc0000000000 R14: ffff8880b325c000 R15: 1ffff110130d0ddb
[   28.308697]  close_ctree+0x33d/0x840
[   28.312391]  ? btrfs_cleanup_transaction.isra.0+0x10d0/0x10d0
[   28.318265]  ? dispose_list+0x1e0/0x1e0
[   28.322222]  ? fsnotify_unmount_inodes+0x1b4/0x210
[   28.327131]  ? btrfs_set_super+0x60/0x60
[   28.331177]  generic_shutdown_super+0x144/0x370
[   28.335824]  kill_anon_super+0x36/0x90
[   28.339691]  btrfs_kill_super+0x49/0x540
[   28.343734]  ? unregister_shrinker+0x170/0x210
[   28.348299]  deactivate_locked_super+0x6c/0xd0
[   28.352858]  deactivate_super+0x7f/0xa0
[   28.356810]  cleanup_mnt+0x186/0x2c0
[   28.360504]  task_work_run+0x11f/0x190
[   28.364372]  do_exit+0xa44/0x2850
[   28.367808]  ? __do_page_fault+0x571/0xad0
[   28.372024]  ? mm_update_next_owner+0x5b0/0x5b0
[   28.376686]  ? lock_downgrade+0x740/0x740
[   28.381664]  do_group_exit+0x100/0x2e0
[   28.385538]  SyS_exit_group+0x19/0x20
[   28.389321]  ? do_group_exit+0x2e0/0x2e0
[   28.393363]  do_syscall_64+0x1d5/0x640
[   28.397245]  entry_SYSCALL_64_after_hwframe+0x5e/0xd3
[   28.402417] RIP: 0033:0x7f5fdafe4d49
[   28.406125] RSP: 002b:00007ffc0bcbc0a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
[   28.413822] RAX: ffffffffffffffda RBX: 00007f5fdb05f3f0 RCX: 00007f5fdafe4d49
[   28.421072] RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000001
[   28.428323] RBP: 0000000000000001 R08: ffffffffffffffc0 R09: 00007ffc0bcbc298
[   28.435579] R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5fdb05f3f0
[   28.442830] R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001
[   28.450439] Kernel Offset: disabled
[   28.454099] Rebooting in 86400 seconds..