[[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 '10.128.0.171' (ECDSA) to the list of known hosts.
executing program
syzkaller login: [ 61.618442][ T6832] IPVS: ftp: loaded support on port[0] = 21
[ 61.753115][ C1] ------------[ cut here ]------------
[ 61.753121][ C1] kernel BUG at net/l2tp/l2tp_core.c:1572!
[ 61.764802][ C1] invalid opcode: 0000 [#1] PREEMPT SMP KASAN
[ 61.772371][ C1] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.8.0-rc1-syzkaller #0
[ 61.780251][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 61.790674][ C1] RIP: 0010:l2tp_session_free+0x218/0x250
[ 61.796404][ C1] Code: 89 ef e8 8b 4a 4d fc e9 4b ff ff ff e8 41 b2 29 fa 4c 89 e7 e8 49 f4 e1 fe e9 39 ff ff ff e8 2f b2 29 fa 0f 0b e8 28 b2 29 fa <0f> 0b 4c 89 e7 e8 1e 01 69 fa e9 48 fe ff ff 48 89 df e8 11 01 69
[ 61.816276][ C1] RSP: 0018:ffffc90000da8d60 EFLAGS: 00010246
[ 61.822430][ C1] RAX: 0000000000000000 RBX: ffff888095ffa400 RCX: ffffffff87499cfd
[ 61.830487][ C1] RDX: ffff8880a9632340 RSI: ffffffff87499e48 RDI: 0000000000000005
[ 61.838720][ C1] RBP: ffff888097f97800 R08: 0000000000000000 R09: ffff888097f978cb
[ 61.846690][ C1] R10: 0000000042114dda R11: 0000000000000000 R12: 0000000000000000
[ 61.855138][ C1] R13: ffff88809f435030 R14: 0000000000000000 R15: ffff8880a9632340
[ 61.863642][ C1] FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
[ 61.872656][ C1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 61.879399][ C1] CR2: 00007f1b5cb0ae78 CR3: 0000000009a79000 CR4: 00000000001406e0
[ 61.887368][ C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 61.898983][ C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 61.907239][ C1] Call Trace:
[ 61.910522][ C1]
[ 61.913366][ C1] pppol2tp_session_destruct+0x12e/0x180
[ 61.919328][ C1] ? pppol2tp_put_sk+0xd0/0xd0
[ 61.924164][ C1] __sk_destruct+0x4b/0x860
[ 61.928663][ C1] sk_destruct+0xbd/0xe0
[ 61.932885][ C1] __sk_free+0xef/0x3d0
[ 61.937015][ C1] sk_free+0x78/0xa0
[ 61.941010][ C1] pppol2tp_put_sk+0x9b/0xd0
[ 61.945601][ C1] rcu_core+0x5c7/0x1160
[ 61.950031][ C1] ? __rcu_read_unlock+0x560/0x560
[ 61.955216][ C1] ? check_preemption_disabled+0x38/0x220
[ 61.961001][ C1] __do_softirq+0x34c/0xa60
[ 61.965486][ C1] asm_call_on_stack+0xf/0x20
[ 61.970130][ C1]
[ 61.973045][ C1] do_softirq_own_stack+0x111/0x170
[ 61.978299][ C1] irq_exit_rcu+0x229/0x270
[ 61.982865][ C1] sysvec_apic_timer_interrupt+0x12d/0x220
[ 61.988830][ C1] asm_sysvec_apic_timer_interrupt+0x12/0x20
[ 61.994783][ C1] RIP: 0010:native_safe_halt+0xe/0x10
[ 62.000157][ C1] Code: ff 4c 89 ef e8 83 9c cb f9 e9 8e fe ff ff 48 89 df e8 76 9c cb f9 eb 8a cc cc cc cc e9 07 00 00 00 0f 00 2d 24 a9 61 00 fb f4 90 e9 07 00 00 00 0f 00 2d 14 a9 61 00 f4 c3 cc cc 55 53 e8 c9
[ 62.019838][ C1] RSP: 0018:ffffc90000d3fc88 EFLAGS: 00000293
[ 62.026088][ C1] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffffffff155cad2
[ 62.034139][ C1] RDX: ffff8880a9632340 RSI: ffffffff87e706f8 RDI: ffff8880a9632bc0
[ 62.042108][ C1] RBP: ffff8880a6655864 R08: 0000000000000000 R09: 0000000000000001
[ 62.050112][ C1] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a6655864
[ 62.058251][ C1] R13: 1ffff920001a7f9b R14: ffff8880a6655865 R15: 0000000000000001
[ 62.066416][ C1] ? acpi_safe_halt+0x88/0x110
[ 62.071177][ C1] acpi_safe_halt+0x8d/0x110
[ 62.075779][ C1] acpi_idle_do_entry+0x15c/0x1b0
[ 62.080792][ C1] acpi_idle_enter+0x3f9/0xab0
[ 62.085755][ C1] ? acpi_idle_enter_bm+0x2d0/0x2d0
[ 62.091090][ C1] ? kvm_sched_clock_read+0x14/0x40
[ 62.096394][ C1] ? sched_clock+0x2a/0x40
[ 62.100968][ C1] ? sched_clock_cpu+0x18/0x1b0
[ 62.105816][ C1] ? check_preemption_disabled+0x38/0x220
[ 62.111750][ C1] cpuidle_enter_state+0xff/0x960
[ 62.117367][ C1] ? check_preemption_disabled+0x38/0x220
[ 62.123856][ C1] ? check_preemption_disabled+0x38/0x220
[ 62.129656][ C1] cpuidle_enter+0x4a/0xa0
[ 62.134397][ C1] do_idle+0x431/0x6a0
[ 62.138559][ C1] ? arch_cpu_idle_exit+0x70/0x70
[ 62.143763][ C1] cpu_startup_entry+0x14/0x20
[ 62.149088][ C1] start_secondary+0x2b3/0x370
[ 62.153950][ C1] ? set_cpu_sibling_map+0x1e80/0x1e80
[ 62.159535][ C1] secondary_startup_64+0xa4/0xb0
[ 62.164555][ C1] Modules linked in:
[ 62.168665][ C1] ---[ end trace 2ea598228637e285 ]---
[ 62.174238][ C1] RIP: 0010:l2tp_session_free+0x218/0x250
[ 62.179991][ C1] Code: 89 ef e8 8b 4a 4d fc e9 4b ff ff ff e8 41 b2 29 fa 4c 89 e7 e8 49 f4 e1 fe e9 39 ff ff ff e8 2f b2 29 fa 0f 0b e8 28 b2 29 fa <0f> 0b 4c 89 e7 e8 1e 01 69 fa e9 48 fe ff ff 48 89 df e8 11 01 69
[ 62.201587][ C1] RSP: 0018:ffffc90000da8d60 EFLAGS: 00010246
[ 62.208620][ C1] RAX: 0000000000000000 RBX: ffff888095ffa400 RCX: ffffffff87499cfd
[ 62.216751][ C1] RDX: ffff8880a9632340 RSI: ffffffff87499e48 RDI: 0000000000000005
[ 62.224850][ C1] RBP: ffff888097f97800 R08: 0000000000000000 R09: ffff888097f978cb
[ 62.233243][ C1] R10: 0000000042114dda R11: 0000000000000000 R12: 0000000000000000
[ 62.241226][ C1] R13: ffff88809f435030 R14: 0000000000000000 R15: ffff8880a9632340
[ 62.249233][ C1] FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
[ 62.258303][ C1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 62.264935][ C1] CR2: 00007f1b5cb0ae78 CR3: 0000000009a79000 CR4: 00000000001406e0
[ 62.273215][ C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 62.282356][ C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 62.290339][ C1] Kernel panic - not syncing: Fatal exception in interrupt
[ 62.299540][ C1] Kernel Offset: disabled
[ 62.303890][ C1] Rebooting in 86400 seconds..