IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
l2tp_core: tunl 4: sockfd_lookup(fd=3) returned -9
==================================================================
BUG: KASAN: use-after-free in l2tp_session_queue_purge+0xf4/0x100 net/l2tp/l2tp_core.c:830
Read of size 4 at addr ffff8801ceec3b80 by task syz-executor5/7214

CPU: 1 PID: 7214 Comm: syz-executor5 Not tainted 4.4.146-g1396226 #15
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 03fb76c3fa008e9a ffff8801c6f4fc78 ffffffff81e1292d
 ffffea00073bb080 ffff8801ceec3b80 0000000000000000 ffff8801ceec3b80
 ffffffff82f1f7c0 ffff8801c6f4fcb0 ffffffff81517f76 ffff8801ceec3b80
Call Trace:
 [<ffffffff81e1292d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81e1292d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff81517f76>] print_address_description+0x6c/0x216 mm/kasan/report.c:252
 [<ffffffff81518295>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff81518295>] kasan_report.cold.7+0x175/0x2f7 mm/kasan/report.c:408
 [<ffffffff814fbd64>] __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:428
 [<ffffffff835a0ff4>] l2tp_session_queue_purge+0xf4/0x100 net/l2tp/l2tp_core.c:830
 [<ffffffff835adb2f>] pppol2tp_release+0x1ff/0x310 net/l2tp/l2tp_ppp.c:509
 [<ffffffff82f1f696>] sock_release+0x96/0x1c0 net/socket.c:587
 [<ffffffff82f1f7d6>] sock_close+0x16/0x20 net/socket.c:1038
 [<ffffffff81525365>] __fput+0x235/0x6f0 fs/file_table.c:208
 [<ffffffff815258a5>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff8118e00f>] task_work_run+0x10f/0x190 kernel/task_work.c:115
 [<ffffffff8100362d>] tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 [<ffffffff8100362d>] exit_to_usermode_loop+0x13d/0x160 arch/x86/entry/common.c:253
 [<ffffffff8100708e>] prepare_exit_to_usermode arch/x86/entry/common.c:284 [inline]
 [<ffffffff8100708e>] syscall_return_slowpath arch/x86/entry/common.c:349 [inline]
 [<ffffffff8100708e>] do_syscall_32_irqs_on arch/x86/entry/common.c:399 [inline]
 [<ffffffff8100708e>] do_fast_syscall_32+0x61e/0x8b0 arch/x86/entry/common.c:460
 [<ffffffff838ca383>] sysenter_flags_fixed+0xd/0x1a

Allocated by task 7226:
 [<ffffffff81034676>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff814fae33>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512
 [<ffffffff814fb117>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff814fb117>] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:616
 [<ffffffff814f7834>] __kmalloc+0x124/0x310 mm/slub.c:3613
 [<ffffffff835a6439>] kmalloc include/linux/slab.h:481 [inline]
 [<ffffffff835a6439>] kzalloc include/linux/slab.h:620 [inline]
 [<ffffffff835a6439>] l2tp_session_create+0x39/0x1030 net/l2tp/l2tp_core.c:1748
 [<ffffffff835ab140>] pppol2tp_connect+0x10f0/0x1910 net/l2tp/l2tp_ppp.c:725
 [<ffffffff82f240b8>] SYSC_connect+0x1b8/0x300 net/socket.c:1558
 [<ffffffff82f269f4>] SyS_connect+0x24/0x30 net/socket.c:1539
 [<ffffffff81006d94>] do_syscall_32_irqs_on arch/x86/entry/common.c:393 [inline]
 [<ffffffff81006d94>] do_fast_syscall_32+0x324/0x8b0 arch/x86/entry/common.c:460
 [<ffffffff838ca383>] sysenter_flags_fixed+0xd/0x1a

Freed by task 7236:
 [<ffffffff81034676>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff814fae33>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512
 [<ffffffff814fb762>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff814fb762>] kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:589
 [<ffffffff814f8c64>] slab_free_hook mm/slub.c:1383 [inline]
 [<ffffffff814f8c64>] slab_free_freelist_hook mm/slub.c:1405 [inline]
 [<ffffffff814f8c64>] slab_free mm/slub.c:2859 [inline]
 [<ffffffff814f8c64>] kfree+0xf4/0x310 mm/slub.c:3749
 [<ffffffff835a33a0>] l2tp_session_free+0x170/0x200 net/l2tp/l2tp_core.c:1676
 [<ffffffff835a5759>] l2tp_session_dec_refcount_1 net/l2tp/l2tp_core.h:293 [inline]
 [<ffffffff835a5759>] l2tp_tunnel_closeall+0x2b9/0x350 net/l2tp/l2tp_core.c:1279
 [<ffffffff835a626b>] l2tp_udp_encap_destroy+0x8b/0xf0 net/l2tp/l2tp_core.c:1300
 [<ffffffff83498271>] udpv6_destroy_sock+0xb1/0xd0 net/ipv6/udp.c:1421
 [<ffffffff82f34f8d>] sk_common_release+0x6d/0x300 net/core/sock.c:2680
 [<ffffffff83496f25>] udp_lib_close+0x15/0x20 include/net/udp.h:190
 [<ffffffff832fe88f>] inet_release+0xff/0x1d0 net/ipv4/af_inet.c:435
 [<ffffffff83421520>] inet6_release+0x50/0x70 net/ipv6/af_inet6.c:424
 [<ffffffff82f1f696>] sock_release+0x96/0x1c0 net/socket.c:587
 [<ffffffff82f1f7d6>] sock_close+0x16/0x20 net/socket.c:1038
 [<ffffffff81525365>] __fput+0x235/0x6f0 fs/file_table.c:208
 [<ffffffff815258a5>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff8118e00f>] task_work_run+0x10f/0x190 kernel/task_work.c:115
 [<ffffffff8100362d>] tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 [<ffffffff8100362d>] exit_to_usermode_loop+0x13d/0x160 arch/x86/entry/common.c:253
 [<ffffffff8100708e>] prepare_exit_to_usermode arch/x86/entry/common.c:284 [inline]
 [<ffffffff8100708e>] syscall_return_slowpath arch/x86/entry/common.c:349 [inline]
 [<ffffffff8100708e>] do_syscall_32_irqs_on arch/x86/entry/common.c:399 [inline]
 [<ffffffff8100708e>] do_fast_syscall_32+0x61e/0x8b0 arch/x86/entry/common.c:460
 [<ffffffff838ca383>] sysenter_flags_fixed+0xd/0x1a

The buggy address belongs to the object at ffff8801ceec3b80
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 0 bytes inside of
 512-byte region [ffff8801ceec3b80, ffff8801ceec3d80)
The buggy address belongs to the page:
kernel tried to execute NX-protected page - exploit attempt? (uid: 0)
page:ffffea00073bb080 count:1 mapcount:786445 mapping:          (null) index:0x0
flags: 0xffff8801c75ffd29(locked|uptodate|lru|owner_priv_1|reserved|private|private_2|writeback|head|swapcache|mappedtodisk|reclaim|swapbacked|unevictable|mlocked|compound_lock)
page dumped because: VM_BUG_ON_PAGE(PageSlab(page))
BUG: unable to handle kernel paging request at ffff8801ceec3d80
IP: [<ffff8801ceec3d80>] 0xffff8801ceec3d80
PGD 6330067 PUD 80000001c00001e3 
Oops: 0011 [#1] PREEMPT SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.146-g1396226 #15
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffffffff84417840 task.stack: ffffffff84400000
RIP: 0010:[<ffff8801ceec3d80>]  [<ffff8801ceec3d80>] 0xffff8801ceec3d80
RSP: 0018:ffff8801db207db0  EFLAGS: 00010006
RAX: ffffffff84417840 RBX: ffff8801c6f47d28 RCX: 0000000000000000
RDX: 0000000000010000 RSI: ffffffff812a0005 RDI: ffff8801c6f47d28
RBP: ffff8801db207ee0 R08: ffffffff85356280 R09: 0000000000000001
R10: 0000000000000000 R11: ffffffff84417840 R12: ffff8801ceec3d80
R13: ffff8801db2196c0 R14: dffffc0000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff8801ceec3d80 CR3: 00000000b1b8a000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff812a000d 0000000000000046 ffff8801db207e78 ffffffff84417840
 1ffff1003b640fc3 ffff8801db219720 ffffed003b640fcf 0000000000000001
 ffff8801db219780 0303880200000001 ffff8801db2196f8 ffff8801db219798
Call Trace:
 <IRQ> 
 [<ffffffff812a1781>] hrtimer_interrupt+0x1b1/0x430 kernel/time/hrtimer.c:1359
 [<ffffffff810af3b4>] local_apic_timer_interrupt+0x74/0xa0 arch/x86/kernel/apic/apic.c:901
 [<ffffffff838cb69c>] smp_apic_timer_interrupt+0x7c/0xa0 arch/x86/kernel/apic/apic.c:925
 [<ffffffff838ca5e0>] apic_timer_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:741
 <EOI> 
 [<ffffffff81025cd5>] arch_safe_halt arch/x86/include/asm/paravirt.h:117 [inline]
 [<ffffffff81025cd5>] default_idle+0x55/0x3c0 arch/x86/kernel/process.c:432
 [<ffffffff81027be0>] arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:423
 [<ffffffff8121de97>] default_idle_call+0x57/0x70 kernel/sched/idle.c:93
 [<ffffffff8121e63f>] cpuidle_idle_call kernel/sched/idle.c:157 [inline]
 [<ffffffff8121e63f>] cpu_idle_loop kernel/sched/idle.c:253 [inline]
 [<ffffffff8121e63f>] cpu_startup_entry+0x6af/0x780 kernel/sched/idle.c:301
 [<ffffffff838b5b71>] rest_init+0x188/0x18e init/main.c:410
 [<ffffffff84a4d8a1>] start_kernel+0x6b3/0x6e7 init/main.c:682
 [<ffffffff84a4c30f>] x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:196
 [<ffffffff84a4c450>] x86_64_start_kernel+0x13f/0x162 arch/x86/kernel/head64.c:185
Code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <3a> 1c 00 00 50 01 e0 ec 44 1c 00 00 52 01 e0 82 00 00 00 00 00 
RIP  [<ffff8801ceec3d80>] 0xffff8801ceec3d80
 RSP <ffff8801db207db0>
CR2: ffff8801ceec3d80
---[ end trace acf410420ebc8b3b ]---
------------[ cut here ]------------
kernel BUG at include/linux/mm.h:464!
invalid opcode: 0000 [#2] PREEMPT SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 7214 Comm: syz-executor5 Tainted: G      D         4.4.146-g1396226 #15
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8800bb8c1800 task.stack: ffff8801c6f48000
RIP: 0010:[<ffffffff8148f497>]  [<ffffffff8148f497>] dump_page mm/debug.c:105 [inline]
RIP: 0010:[<ffffffff8148f497>]  [<ffffffff8148f497>] page_mapcount include/linux/mm.h:464 [inline]
RIP: 0010:[<ffffffff8148f497>]  [<ffffffff8148f497>] dump_page_badflags+0x57/0x70 mm/debug.c:85
RSP: 0018:ffff8801c6c00028  EFLAGS: 00010093
RAX: 0000000000000000 RBX: ffffea00073bb080 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff81515fa9 RDI: ffff8800bb8c20dc
RBP: ffff8801c6c00058 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: ffffffff858fc15b R12: 0000000000000000
R13: ffffffff83aaad60 R14: ffff8801ceec3b80 R15: ffff8801ceec3d80
FS:  0000000000000000(0000) GS:ffff8801db300000(0063) knlGS:000000000915b900
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000000625208 CR3: 00000001d2135000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 0000000000000000 ffffea00073bb080 0000000000000000 ffffffff83aaad60
 ffff8801ceec3b80 ffff8801ceec3d80 ffff8801c6c00098 ffffffff8148f497
 0000000000000000 ffffea00073bb080 0000000000000000 ffffffff83aaad60
Call Trace:
 <UNK> 
Code: 48 c1 ea 03 80 3c 02 00 75 23 48 8b 03 a8 80 0f 84 f6 69 08 00 e8 2a 43 ec ff 31 d2 48 c7 c6 60 ad aa 83 48 89 df e8 a9 ff ff ff <0f> 0b 48 89 df e8 cf c8 06 00 eb d3 0f 1f 00 66 2e 0f 1f 84 00 
RIP  [<ffffffff8148f497>] dump_page mm/debug.c:105 [inline]
RIP  [<ffffffff8148f497>] page_mapcount include/linux/mm.h:464 [inline]
RIP  [<ffffffff8148f497>] dump_page_badflags+0x57/0x70 mm/debug.c:85
 RSP <ffff8801c6c00028>
---[ end trace acf410420ebc8b3c ]---