[[0;32m OK [0m] Started Getty on tty4.
[[0;32m OK [0m] Started Getty on tty3.
[[0;32m OK [0m] Started Getty on tty2.
[[0;32m OK [0m] Started Getty on tty1.
[[0;32m OK [0m] Started Serial Getty on ttyS0.
[[0;32m OK [0m] Reached target Login Prompts.
[[0;32m OK [0m] Reached target Multi-User System.
[[0;32m OK [0m] Reached target Graphical Interface.
Starting Update UTMP about System Runlevel Changes...
[[0;32m OK [0m] Started Update UTMP about System Runlevel Changes.
Starting Load/Save RF Kill Switch Status...
[[0;32m OK [0m] Started Load/Save RF Kill Switch Status.
Debian GNU/Linux 9 syzkaller ttyS0
Warning: Permanently added '10.128.10.51' (ECDSA) to the list of known hosts.
executing program
syzkaller login: [ 61.946871][ T6809] IPVS: ftp: loaded support on port[0] = 21
[ 62.066861][ C0] ------------[ cut here ]------------
[ 62.072911][ C0] kernel BUG at net/l2tp/l2tp_core.c:1572!
[ 62.079165][ C0] invalid opcode: 0000 [#1] PREEMPT SMP KASAN
[ 62.085243][ C0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.7.0-syzkaller #0
[ 62.092885][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 62.102964][ C0] RIP: 0010:l2tp_session_free+0x218/0x250
[ 62.109007][ C0] Code: 89 ef e8 1b 04 5a fc e9 4b ff ff ff e8 51 94 33 fa 4c 89 e7 e8 b9 c8 e1 fe e9 39 ff ff ff e8 3f 94 33 fa 0f 0b e8 38 94 33 fa <0f> 0b 4c 89 e7 e8 7e a9 72 fa e9 48 fe ff ff 48 89 df e8 71 a9 72
[ 62.129384][ C0] RSP: 0018:ffffc90000007d28 EFLAGS: 00010246
[ 62.135455][ C0] RAX: ffffffff89886580 RBX: ffff8880a88d9800 RCX: ffffffff8740393d
[ 62.143463][ C0] RDX: 0000000000000000 RSI: ffffffff87403a88 RDI: 0000000000000005
[ 62.151667][ C0] RBP: ffff888092849800 R08: ffffffff89886580 R09: ffffed101250931a
[ 62.159732][ C0] R10: ffff8880928498cb R11: ffffed1012509319 R12: 0000000000000000
[ 62.167720][ C0] R13: ffff888097e084a8 R14: ffffc90000007e98 R15: ffffffff89886580
[ 62.175873][ C0] FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
[ 62.184787][ C0] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 62.191371][ C0] CR2: 00000000080e3dc8 CR3: 0000000009879000 CR4: 00000000001406f0
[ 62.199408][ C0] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 62.207456][ C0] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 62.215410][ C0] Call Trace:
[ 62.218672][ C0]
[ 62.221522][ C0] pppol2tp_session_destruct+0x12e/0x180
[ 62.227145][ C0] ? pppol2tp_recvmsg+0x270/0x270
[ 62.234376][ C0] __sk_destruct+0x4b/0x7c0
[ 62.238861][ C0] sk_destruct+0xc6/0x100
[ 62.243356][ C0] __sk_free+0xef/0x3d0
[ 62.247488][ C0] sk_free+0x78/0xa0
[ 62.251379][ C0] pppol2tp_put_sk+0x9b/0xd0
[ 62.255950][ C0] rcu_core+0x59f/0x1370
[ 62.260183][ C0] ? __rcu_read_unlock+0x560/0x560
[ 62.265533][ C0] ? rcu_read_lock_sched_held+0x9c/0xd0
[ 62.271055][ C0] ? rcu_read_lock_any_held.part.0+0x50/0x50
[ 62.277025][ C0] __do_softirq+0x26c/0x9f7
[ 62.281596][ C0] irq_exit+0x192/0x1d0
[ 62.285730][ C0] smp_apic_timer_interrupt+0x19e/0x600
[ 62.292833][ C0] apic_timer_interrupt+0xf/0x20
[ 62.298542][ C0]
[ 62.301692][ C0] RIP: 0010:native_safe_halt+0xe/0x10
[ 62.307147][ C0] Code: cc cc cc cc cc cc cc cc cc cc cc cc e9 07 00 00 00 0f 00 2d 84 9c 4a 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d 74 9c 4a 00 fb f4 cc 41 56 41 55 41 54 55 53 e8 33 9c 83 f9 e8 be c8 bf fb 0f 1f
[ 62.327011][ C0] RSP: 0018:ffffffff89807c50 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13
[ 62.335903][ C0] RAX: ffffffff89886580 RBX: 0000000000000000 RCX: 1ffffffff15173ba
[ 62.344637][ C0] RDX: 0000000000000000 RSI: ffffffff87de1248 RDI: ffffffff89886e00
[ 62.352870][ C0] RBP: ffff88821a898064 R08: 0000000000000000 R09: 0000000000000001
[ 62.361012][ C0] R10: 0000000000000000 R11: 0000000000000000 R12: ffff88821a898064
[ 62.369049][ C0] R13: 1ffffffff1300f95 R14: ffff88821a898065 R15: 0000000000000001
[ 62.377471][ C0] ? acpi_safe_halt+0x88/0x110
[ 62.382331][ C0] acpi_safe_halt+0x8d/0x110
[ 62.386930][ C0] acpi_idle_do_entry+0xa9/0xe0
[ 62.392143][ C0] acpi_idle_enter+0x437/0xb20
[ 62.397171][ C0] ? acpi_idle_enter_bm+0x2d0/0x2d0
[ 62.402529][ C0] ? kvm_clock_read+0x14/0x30
[ 62.407194][ C0] ? kvm_sched_clock_read+0x5/0x10
[ 62.412617][ C0] ? sched_clock+0x2a/0x40
[ 62.417027][ C0] ? sched_clock_cpu+0x18/0x1b0
[ 62.422149][ C0] cpuidle_enter_state+0xdd/0xd60
[ 62.427176][ C0] ? assoc_array_gc+0x1200/0x1250
[ 62.432274][ C0] cpuidle_enter+0x4a/0xa0
[ 62.436753][ C0] do_idle+0x42f/0x690
[ 62.440982][ C0] ? arch_cpu_idle_exit+0x70/0x70
[ 62.446788][ C0] ? trace_init_perf_perm_irq_work_exit+0xe/0xe
[ 62.453203][ C0] cpu_startup_entry+0x14/0x20
[ 62.458179][ C0] start_kernel+0x9be/0x9fb
[ 62.464258][ C0] ? mem_encrypt_init+0x5/0x5
[ 62.468914][ C0] ? x86_family+0x3d/0x50
[ 62.473229][ C0] ? load_ucode_bsp+0x23d/0x27d
[ 62.478144][ C0] secondary_startup_64+0xa4/0xb0
[ 62.483156][ C0] Modules linked in:
[ 62.487283][ C0] ---[ end trace 54b49e784da2e192 ]---
[ 62.492940][ C0] RIP: 0010:l2tp_session_free+0x218/0x250
[ 62.498731][ C0] Code: 89 ef e8 1b 04 5a fc e9 4b ff ff ff e8 51 94 33 fa 4c 89 e7 e8 b9 c8 e1 fe e9 39 ff ff ff e8 3f 94 33 fa 0f 0b e8 38 94 33 fa <0f> 0b 4c 89 e7 e8 7e a9 72 fa e9 48 fe ff ff 48 89 df e8 71 a9 72
[ 62.519171][ C0] RSP: 0018:ffffc90000007d28 EFLAGS: 00010246
[ 62.525234][ C0] RAX: ffffffff89886580 RBX: ffff8880a88d9800 RCX: ffffffff8740393d
[ 62.533521][ C0] RDX: 0000000000000000 RSI: ffffffff87403a88 RDI: 0000000000000005
[ 62.541594][ C0] RBP: ffff888092849800 R08: ffffffff89886580 R09: ffffed101250931a
[ 62.549895][ C0] R10: ffff8880928498cb R11: ffffed1012509319 R12: 0000000000000000
[ 62.558109][ C0] R13: ffff888097e084a8 R14: ffffc90000007e98 R15: ffffffff89886580
[ 62.566146][ C0] FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
[ 62.576801][ C0] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 62.583389][ C0] CR2: 00000000080e3dc8 CR3: 0000000009879000 CR4: 00000000001406f0
[ 62.591413][ C0] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 62.601367][ C0] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 62.609585][ C0] Kernel panic - not syncing: Fatal exception in interrupt
[ 62.618389][ C0] Kernel Offset: disabled
[ 62.622726][ C0] Rebooting in 86400 seconds..