[ OK ] Started Daily apt upgrade and clean activities. [ OK ] Reached target Timers. [ OK ] Started Permit User Sessions. [ OK ] Found device /dev/ttyS0. [ OK ] Started System Logging Service. [ OK ] Started getty on tty2-tty6 if dbus and logind are not available. [ OK ] Started OpenBSD Secure Shell server. [ OK ] Listening on Load/Save RF Kill Switch Status /dev/rfkill Watch. [ OK ] Started Getty on tty6. [ OK ] Started Getty on tty5. [ OK ] Started Getty on tty4. [ OK ] Started Getty on tty3. [ OK ] Started Getty on tty2. [ OK ] Started Getty on tty1. [ 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 '10.128.1.121' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 32.095821] ------------[ cut here ]------------ [ 32.100616] DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock)) [ 32.100673] WARNING: CPU: 0 PID: 8095 at kernel/locking/mutex-debug.c:103 mutex_destroy+0xec/0x130 [ 32.115133] Kernel panic - not syncing: panic_on_warn set ... [ 32.115133] [ 32.122585] CPU: 0 PID: 8095 Comm: syz-executor415 Not tainted 4.19.211-syzkaller #0 [ 32.130443] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 32.139787] Call Trace: [ 32.142362] dump_stack+0x1fc/0x2ef [ 32.145978] panic+0x26a/0x50e [ 32.149157] ? __warn_printk+0xf3/0xf3 [ 32.153024] ? mutex_destroy+0xec/0x130 [ 32.156980] ? __probe_kernel_read+0x130/0x1b0 [ 32.161548] ? __warn.cold+0x5/0x5a [ 32.165159] ? __warn+0xe4/0x200 [ 32.168508] ? mutex_destroy+0xec/0x130 [ 32.172465] __warn.cold+0x20/0x5a [ 32.175991] ? kvm_sched_clock_read+0x14/0x40 [ 32.180467] ? mutex_destroy+0xec/0x130 [ 32.184428] report_bug+0x262/0x2b0 [ 32.188035] do_error_trap+0x1d7/0x310 [ 32.191907] ? math_error+0x310/0x310 [ 32.195688] ? vprintk_store+0x1f0/0x410 [ 32.199748] ? trace_hardirqs_on+0x55/0x210 [ 32.204057] ? error_entry+0x72/0xd0 [ 32.207756] ? trace_hardirqs_off_caller+0x6e/0x210 [ 32.212759] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 32.217585] invalid_op+0x14/0x20 [ 32.221026] RIP: 0010:mutex_destroy+0xec/0x130 [ 32.225595] Code: 11 38 d0 7c 04 84 d2 75 50 8b 05 6f 93 ec 0b 85 c0 0f 85 63 ff ff ff 48 c7 c6 c0 0f 6a 88 48 c7 c7 00 10 6a 88 e8 69 59 a8 06 <0f> 0b e9 49 ff ff ff 48 c7 c7 60 37 24 8d e8 d1 fd 4d 00 e9 2e ff [ 32.244478] RSP: 0018:ffff8880b4f87de0 EFLAGS: 00010286 [ 32.249825] RAX: 0000000000000000 RBX: ffff8880b37c8600 RCX: 0000000000000000 [ 32.257075] RDX: 0000000000000000 RSI: ffffffff814dff01 RDI: ffffed10169f0fae [ 32.264323] RBP: ffff8880b37c8480 R08: 0000000000000000 R09: 00000000000006dd [ 32.271569] R10: 0000000000000006 R11: ffffffff8c66501b R12: 0000000000000000 [ 32.278822] R13: ffff8880b37c8600 R14: ffff8880b2ac5bc8 R15: ffff8880b5b84820 [ 32.286096] ? vprintk_func+0x81/0x180 [ 32.289974] dma_buf_release+0x531/0x630 [ 32.294015] ? ima_file_free+0xb6/0x460 [ 32.297970] ? dma_buf_detach+0x240/0x240 [ 32.302096] __fput+0x2ce/0x890 [ 32.305357] task_work_run+0x148/0x1c0 [ 32.309227] exit_to_usermode_loop+0x251/0x2a0 [ 32.313789] do_syscall_64+0x538/0x620 [ 32.317657] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 32.322823] RIP: 0033:0x7fea6096a179 [ 32.326515] Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 [ 32.345396] RSP: 002b:00007fea608f62f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 32.353083] RAX: 0000000000000000 RBX: 00007fea609ed438 RCX: 00007fea6096a179 [ 32.360333] RDX: 0000000020000140 RSI: 0000000040086409 RDI: 0000000000000003 [ 32.367580] RBP: 0000000000000000 R08: 00007fea608f6700 R09: 0000000000000000 [ 32.374832] R10: 00007fea608f6700 R11: 0000000000000246 R12: 00007ffef8d328fe [ 32.382085] R13: 00007fea609ed430 R14: 00007fea609ed43c R15: 00007fea609bb074 [ 32.389506] Kernel Offset: disabled [ 32.393117] Rebooting in 86400 seconds..