[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Update UTMP about System Runlevel Changes. [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.186' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 68.030916] audit: type=1400 audit(1601636905.905:8): avc: denied { execmem } for pid=6486 comm="syz-executor274" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 [ 68.060349] BTRFS: device fsid f90cac8b-044b-4fa8-8bee-4b8d3da88dc2 devid 1 transid 7 /dev/loop0 [ 68.077241] BTRFS info (device loop0): turning on flush-on-commit [ 68.084541] BTRFS info (device loop0): disk space caching is enabled [ 68.091496] BTRFS info (device loop0): has skinny extents [ 68.128020] BTRFS info (device loop0): checking UUID tree [ 68.143287] ------------[ cut here ]------------ [ 68.148378] WARNING: CPU: 1 PID: 6514 at fs/fs-writeback.c:2394 __writeback_inodes_sb_nr.cold+0x11/0x18 [ 68.157922] Kernel panic - not syncing: panic_on_warn set ... [ 68.157922] [ 68.165327] CPU: 1 PID: 6514 Comm: btrfs-transacti Not tainted 4.19.149-syzkaller #0 [ 68.173213] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 68.182569] Call Trace: [ 68.185169] dump_stack+0x22c/0x33e [ 68.188810] panic+0x2ac/0x565 [ 68.192009] ? __warn_printk+0xf3/0xf3 [ 68.196004] ? __writeback_inodes_sb_nr.cold+0x11/0x18 [ 68.201281] ? __probe_kernel_read+0x130/0x1b0 [ 68.205874] ? __warn.cold+0x5/0x5a [ 68.209530] ? __warn+0xe4/0x200 [ 68.213019] ? __writeback_inodes_sb_nr.cold+0x11/0x18 [ 68.218293] __warn.cold+0x20/0x5a [ 68.221833] ? __writeback_inodes_sb_nr.cold+0x11/0x18 [ 68.227091] report_bug+0x262/0x2b0 [ 68.230821] do_error_trap+0x1e1/0x330 [ 68.234698] ? math_error+0x320/0x320 [ 68.238485] ? __irq_work_queue_local+0x155/0x200 [ 68.243329] ? irq_work_queue+0x29/0x80 [ 68.247296] ? error_entry+0x72/0xd0 [ 68.251009] ? trace_hardirqs_off_caller+0x6e/0x210 [ 68.256012] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 68.260842] invalid_op+0x14/0x20 [ 68.264282] RIP: 0010:__writeback_inodes_sb_nr.cold+0x11/0x18 [ 68.270161] Code: 09 c1 af ff 41 0f b6 f5 48 c7 c7 00 f9 94 89 e8 89 11 f4 01 e9 e3 7b ff ff e8 ef c0 af ff 48 c7 c7 e0 5d 16 88 e8 92 3c 99 ff <0f> 0b e9 9a 80 ff ff e8 d7 c0 af ff 0f b6 f3 48 c7 c7 80 f9 94 89 [ 68.289064] RSP: 0018:ffff8880a49ffc48 EFLAGS: 00010286 [ 68.294409] RAX: 0000000000000024 RBX: 1ffff1101493ff8b RCX: 0000000000000000 [ 68.301671] RDX: 0000000000000000 RSI: ffffffff815b623f RDI: ffffed101493ff7b [ 68.308929] RBP: ffff8880a4d10880 R08: 0000000000000024 R09: 0000000000000000 [ 68.316193] R10: 0000000000000005 R11: 0000000000000000 R12: 0000000000006400 [ 68.323449] R13: ffff8880a3f18240 R14: ffff8880a4d109b0 R15: ffff8880a49ffc88 [ 68.330719] ? vprintk_func+0x7f/0x224 [ 68.334601] ? __writeback_inodes_sb_nr.cold+0x11/0x18 [ 68.339883] ? bdi_split_work_to_wbs+0xfe0/0xfe0 [ 68.344628] ? btrfs_commit_transaction+0x1e17/0x24a0 [ 68.349808] ? get_nr_dirty_inodes+0x1fc/0x2d0 [ 68.354388] btrfs_commit_transaction+0x1bb1/0x24a0 [ 68.359478] ? do_raw_spin_unlock+0x171/0x240 [ 68.363963] ? _raw_spin_unlock+0x29/0x40 [ 68.368143] ? btrfs_apply_pending_changes+0x110/0x110 [ 68.373428] ? btrfs_record_root_in_trans+0x13c/0x190 [ 68.378637] ? start_transaction+0x239/0xfc0 [ 68.383035] transaction_kthread+0x385/0x483 [ 68.387461] ? __kthread_parkme+0x133/0x1e0 [ 68.391774] ? open_ctree+0x6340/0x6340 [ 68.395738] kthread+0x33f/0x460 [ 68.399088] ? kthread_park+0x180/0x180 [ 68.403047] ret_from_fork+0x24/0x30 [ 68.408036] Kernel Offset: disabled [ 68.411714] Rebooting in 86400 seconds..