l2tp_ppp: sess 4/0: set debug=cf10464f
l2tp_ppp: sess 4/0: get L2TP stats
BUG: unable to handle kernel paging request at ffffebe018000020
PGD 0 P4D 0 
Oops: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 4543 Comm: syz-executor7 Not tainted 4.16.0+ #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:virt_to_head_page include/linux/mm.h:622 [inline]
RIP: 0010:qlink_to_cache mm/kasan/quarantine.c:127 [inline]
RIP: 0010:qlist_free_all+0x12b/0x160 mm/kasan/quarantine.c:163
RSP: 0018:ffff88019d24eb18 EFLAGS: 00010286
RAX: 00000006000003a8 RBX: 0000000000000282 RCX: ffffea0000000000
RDX: ffffebe018000000 RSI: ffff88019d246970 RDI: 0000000000000282
RBP: ffff88019d24eb50 R08: ffff88019d2468f8 R09: 0000000000000006
R10: ffff88019d246080 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 00000006000003a8 R15: ffffffff88b172a0
FS:  0000000002a03940(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffebe018000020 CR3: 000000019d1fd000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 quarantine_reduce+0x141/0x170 mm/kasan/quarantine.c:259
 kasan_kmalloc+0x99/0xe0 mm/kasan/kasan.c:537
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489
 slab_post_alloc_hook mm/slab.h:443 [inline]
 slab_alloc mm/slab.c:3380 [inline]
 kmem_cache_alloc+0x11b/0x760 mm/slab.c:3540
 ptlock_alloc+0x20/0x80 mm/memory.c:4729
 ptlock_init include/linux/mm.h:1803 [inline]
 pgtable_page_ctor include/linux/mm.h:1837 [inline]
 pte_alloc_one+0x6b/0x120 arch/x86/mm/pgtable.c:32
 __pte_alloc+0x2a/0x340 mm/memory.c:654
 copy_pte_range mm/memory.c:1076 [inline]
 copy_pmd_range mm/memory.c:1152 [inline]
 copy_pud_range mm/memory.c:1186 [inline]
 copy_p4d_range mm/memory.c:1208 [inline]
 copy_page_range+0x1655/0x24b0 mm/memory.c:1270
TCP: request_sock_TCPv6: Possible SYN flooding on port 20000. Sending cookies.  Check SNMP counters.
 dup_mmap kernel/fork.c:513 [inline]
 dup_mm kernel/fork.c:1233 [inline]
 copy_mm kernel/fork.c:1287 [inline]
 copy_process.part.39+0x4be7/0x6ee0 kernel/fork.c:1793
 copy_process kernel/fork.c:1606 [inline]
 _do_fork+0x291/0x12a0 kernel/fork.c:2087
 SYSC_clone kernel/fork.c:2194 [inline]
 SyS_clone+0x37/0x50 kernel/fork.c:2188
 do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45398a
RSP: 002b:0000000000a3ea70 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000a3ea70 RCX: 000000000045398a
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000a3eab0 R08: 0000000000000001 R09: 0000000002a03940
R10: 0000000002a03c10 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000001380
Code: 00 00 00 80 48 01 c2 72 43 48 b9 00 00 00 80 ff 77 00 00 48 01 ca 48 b9 00 00 00 00 00 ea ff ff 48 c1 ea 0c 48 c1 e2 06 48 01 ca <48> 8b 4a 20 48 8d 71 ff 83 e1 01 48 0f 45 d6 4c 8b 6a 30 e9 f4 
RIP: virt_to_head_page include/linux/mm.h:622 [inline] RSP: ffff88019d24eb18
RIP: qlink_to_cache mm/kasan/quarantine.c:127 [inline] RSP: ffff88019d24eb18
RIP: qlist_free_all+0x12b/0x160 mm/kasan/quarantine.c:163 RSP: ffff88019d24eb18
CR2: ffffebe018000020
---[ end trace 449c7322f9349e1a ]---