[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
Starting mcstransd: 
[   11.879317] random: crng init done
[....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

Warning: Permanently added '10.128.0.241' (ECDSA) to the list of known hosts.
executing program
syzkaller login: [   39.972011] ------------[ cut here ]------------
[   39.976837] WARNING: CPU: 0 PID: 2060 at fs/buffer.c:1197 __brelse+0x6c/0x80
[   39.984497] VFS: brelse: Trying to free free buffer
[   39.990029] Kernel panic - not syncing: panic_on_warn set ...
[   39.990029] 
[   39.998065] CPU: 0 PID: 2060 Comm: syz-executor543 Not tainted 4.9.166+ #35
[   40.006245]  ffff8801cedaf8b0 ffffffff81b4ef81 ffff8801cedafa00 ffffffff82a39ba0
[   40.014708]  00000000ffffffff 0000000000000000 0000000000000009 ffff8801cedaf990
[   40.023977]  ffffffff813f91aa 0000000041b58ab3 ffffffff82e2ec1a ffffffff813f8fd1
[   40.033208] Call Trace:
[   40.035971]  [<00000000034285cb>] dump_stack+0xc1/0x120
[   40.041537]  [<0000000027e5214a>] panic+0x1d9/0x3bd
[   40.047146]  [<00000000dbdcbe7e>] ? add_taint.cold+0x16/0x16
[   40.054615]  [<000000000d288514>] ? vprintk_emit+0x277/0x6f0
[   40.060886]  [<00000000e3e3e9ce>] ? __warn.cold+0x14/0x2f
[   40.068908]  [<00000000f6ca6260>] ? __brelse+0x6c/0x80
[   40.074201]  [<00000000fc65cc8a>] __warn.cold+0x2f/0x2f
[   40.079928]  [<00000000370e8802>] warn_slowpath_fmt+0xc2/0x100
[   40.085920]  [<00000000c7717619>] ? __warn+0x1b0/0x1b0
[   40.091322]  [<00000000d8bc0ce1>] ? ext4_free_branches+0x410/0x840
[   40.097640]  [<0000000024c4b172>] ? ext4_get_branch+0x540/0x540
[   40.103779]  [<00000000e44b7171>] ? ext4_block_to_path.isra.0+0xe4/0x550
[   40.110869]  [<00000000f6ca6260>] __brelse+0x6c/0x80
[   40.116264]  [<000000001bf99807>] ext4_ind_remove_space+0xfa3/0x13e0
[   40.122879]  [<0000000062eadc33>] ? ext4_ind_truncate+0x950/0x950
[   40.129201]  [<00000000d241b1c8>] ? __es_remove_extent+0x491/0x6b0
[   40.135621]  [<00000000d1498e23>] ? debug_lockdep_rcu_enabled+0x71/0xa0
[   40.143279]  [<000000008d67338a>] ? __es_insert_extent+0xe60/0xe60
[   40.149848]  [<00000000a4c17088>] ? ext4_es_remove_extent+0xaf/0x320
[   40.159387]  [<000000007522c46d>] ? _raw_write_unlock+0x2d/0x50
[   40.165987]  [<00000000017d29df>] ext4_punch_hole+0xb28/0x1000
[   40.171993]  [<0000000043d49354>] ext4_fallocate+0x34e/0x2070
[   40.177907]  [<0000000019729ac0>] ? rcu_read_lock_sched_held+0x10b/0x130
[   40.184993]  [<00000000a4107052>] ? rcu_sync_lockdep_assert+0x73/0xb0
[   40.191885]  [<000000006e11dd45>] vfs_fallocate+0x407/0x6a0
[   40.197682]  [<00000000daca6fc8>] SyS_fallocate+0x52/0x90
[   40.204283]  [<00000000dbc6d02b>] ? compat_SyS_ftruncate+0x30/0x30
[   40.211046]  [<000000000200ae04>] do_syscall_64+0x1ad/0x570
[   40.217196]  [<00000000ad22cc6b>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
[   40.225256] Kernel Offset: disabled
[   40.228998] Rebooting in 86400 seconds..