[ 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 '10.128.0.65' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 58.701481] audit: type=1400 audit(1600621902.315:8): avc: denied { execmem } for pid=6489 comm="syz-executor640" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 [ 58.729407] BTRFS: device fsid f90cac8b-044b-4fa8-8bee-4b8d3da88dc2 devid 1 transid 7 /dev/loop0 [ 58.749122] BTRFS info (device loop0): turning on flush-on-commit [ 58.760390] BTRFS info (device loop0): disk space caching is enabled [ 58.766924] BTRFS info (device loop0): has skinny extents executing program [ 58.793694] BTRFS info (device loop0): checking UUID tree executing program [ 58.910970] BTRFS info (device loop0): turning on flush-on-commit [ 58.918181] BTRFS info (device loop0): disk space caching is enabled [ 58.925752] BTRFS info (device loop0): has skinny extents [ 58.947625] BTRFS info (device loop0): checking UUID tree executing program [ 59.046579] BTRFS info (device loop0): turning on flush-on-commit [ 59.053103] BTRFS info (device loop0): disk space caching is enabled [ 59.060553] BTRFS info (device loop0): has skinny extents [ 59.082473] BTRFS info (device loop0): checking UUID tree executing program [ 59.148861] BTRFS info (device loop0): turning on flush-on-commit [ 59.157190] BTRFS info (device loop0): disk space caching is enabled [ 59.163871] BTRFS info (device loop0): has skinny extents [ 59.187076] BTRFS info (device loop0): checking UUID tree executing program [ 59.269145] BTRFS info (device loop0): turning on flush-on-commit [ 59.275782] BTRFS info (device loop0): disk space caching is enabled [ 59.283751] BTRFS info (device loop0): has skinny extents [ 59.307301] BTRFS info (device loop0): checking UUID tree [ 59.315648] ------------[ cut here ]------------ [ 59.330631] WARNING: CPU: 0 PID: 6640 at fs/fs-writeback.c:2394 __writeback_inodes_sb_nr.cold+0x11/0x18 [ 59.340184] Kernel panic - not syncing: panic_on_warn set ... [ 59.340184] [ 59.347542] CPU: 0 PID: 6640 Comm: btrfs-transacti Not tainted 4.19.146-syzkaller #0 [ 59.355546] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 59.364903] Call Trace: [ 59.367505] dump_stack+0x22c/0x33e [ 59.371149] panic+0x2ac/0x565 [ 59.374354] ? __warn_printk+0xf3/0xf3 [ 59.378256] ? __writeback_inodes_sb_nr.cold+0x11/0x18 [ 59.383542] ? __probe_kernel_read+0x130/0x1b0 [ 59.388118] ? __warn.cold+0x5/0x5a [ 59.391806] ? __warn+0xe4/0x200 [ 59.395189] ? __writeback_inodes_sb_nr.cold+0x11/0x18 [ 59.400447] __warn.cold+0x20/0x5a [ 59.404006] ? io_schedule_timeout+0x140/0x140 [ 59.408566] ? __writeback_inodes_sb_nr.cold+0x11/0x18 [ 59.413826] report_bug+0x262/0x2b0 [ 59.417457] do_error_trap+0x1e1/0x330 [ 59.421341] ? math_error+0x320/0x320 [ 59.425161] ? __irq_work_queue_local+0x155/0x200 [ 59.429983] ? irq_work_queue+0x29/0x80 [ 59.433935] ? wake_up_klogd+0xef/0x140 [ 59.437889] ? trace_hardirqs_off_caller+0x69/0x210 [ 59.442889] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 59.447719] invalid_op+0x14/0x20 [ 59.451153] RIP: 0010:__writeback_inodes_sb_nr.cold+0x11/0x18 [ 59.457028] Code: 19 d8 af ff 41 0f b6 f5 48 c7 c7 80 f3 94 89 e8 39 05 f4 01 e9 e3 7b ff ff e8 ff d7 af ff 48 c7 c7 e0 5c 16 88 e8 22 53 99 ff <0f> 0b e9 9a 80 ff ff e8 e7 d7 af ff 0f b6 f3 48 c7 c7 00 f4 94 89 [ 59.475929] RSP: 0018:ffff88809f8efc48 EFLAGS: 00010286 [ 59.481283] RAX: 0000000000000024 RBX: 1ffff11013f1df8b RCX: 0000000000000000 [ 59.488535] RDX: 0000000000000000 RSI: ffffffff815b523f RDI: ffffed1013f1df7b [ 59.495783] RBP: ffff8880a44de240 R08: 0000000000000024 R09: 0000000000000000 [ 59.503041] R10: 0000000000000005 R11: 0000000000000000 R12: 0000000000006400 [ 59.510307] R13: ffff8880a08f7480 R14: ffff8880a44de370 R15: ffff88809f8efc88 [ 59.517578] ? vprintk_func+0x7f/0x224 [ 59.521483] ? __writeback_inodes_sb_nr.cold+0x11/0x18 [ 59.526788] ? bdi_split_work_to_wbs+0xfe0/0xfe0 [ 59.531536] ? btrfs_commit_transaction+0x1e17/0x24a0 [ 59.536711] ? get_nr_dirty_inodes+0x1fc/0x2d0 [ 59.541276] btrfs_commit_transaction+0x1bb1/0x24a0 [ 59.546280] ? do_raw_spin_unlock+0x171/0x240 [ 59.550784] ? _raw_spin_unlock+0x29/0x40 [ 59.554915] ? btrfs_apply_pending_changes+0x110/0x110 [ 59.560170] ? btrfs_record_root_in_trans+0x13c/0x190 [ 59.565339] ? start_transaction+0x239/0xfc0 [ 59.569755] transaction_kthread+0x385/0x483 [ 59.574151] ? __kthread_parkme+0x133/0x1e0 [ 59.578451] ? open_ctree+0x6340/0x6340 [ 59.582405] kthread+0x33f/0x460 [ 59.585753] ? kthread_park+0x180/0x180 [ 59.589713] ret_from_fork+0x24/0x30 [ 59.595122] Kernel Offset: disabled [ 59.598817] Rebooting in 86400 seconds..