==================================================================
BUG: KASAN: use-after-free in ip6_dst_idev include/net/ip6_fib.h:141 [inline]
BUG: KASAN: use-after-free in ip6_xmit+0x177c/0x1a00 net/ipv6/ip6_output.c:237
Read of size 8 at addr ffff8800b94cf658 by task syz-executor4/23881

CPU: 1 PID: 23881 Comm: syz-executor4 Not tainted 4.4.153-g5e24b4e #90
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 19a011231ed6e21c ffff8801bc897728 ffffffff81e162ed
 ffffea0002e533c0 ffff8800b94cf658 0000000000000000 ffff8800b94cf658
 0000000000003200 ffff8801bc897760 ffffffff8151b4d9 ffff8800b94cf658
Call Trace:
 [<ffffffff81e162ed>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81e162ed>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff8151b4d9>] print_address_description+0x6c/0x216 mm/kasan/report.c:252
 [<ffffffff8151b7f8>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff8151b7f8>] kasan_report.cold.7+0x175/0x2f7 mm/kasan/report.c:408
 [<ffffffff814fe784>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:429
 [<ffffffff834361fc>] ip6_dst_idev include/net/ip6_fib.h:141 [inline]
 [<ffffffff834361fc>] ip6_xmit+0x177c/0x1a00 net/ipv6/ip6_output.c:237
 [<ffffffff834f63c5>] inet6_csk_xmit+0x245/0x490 net/ipv6/inet6_connection_sock.c:176
 [<ffffffff835a5a0c>] l2tp_xmit_core net/l2tp/l2tp_core.c:1084 [inline]
 [<ffffffff835a5a0c>] l2tp_xmit_skb+0xb9c/0xe80 net/l2tp/l2tp_core.c:1179
 [<ffffffff835b1f60>] pppol2tp_sendmsg+0x4e0/0x7d0 net/l2tp/l2tp_ppp.c:355
 [<ffffffff82f2757c>] sock_sendmsg_nosec net/socket.c:638 [inline]
 [<ffffffff82f2757c>] sock_sendmsg+0xcc/0x110 net/socket.c:648
 [<ffffffff82f277e3>] sock_write_iter+0x223/0x3b0 net/socket.c:847
 [<ffffffff815228cd>] new_sync_write fs/read_write.c:478 [inline]
 [<ffffffff815228cd>] __vfs_write+0x30d/0x3f0 fs/read_write.c:491
 [<ffffffff815244b1>] vfs_write+0x191/0x4e0 fs/read_write.c:538
 [<ffffffff81526ab9>] SYSC_write fs/read_write.c:585 [inline]
 [<ffffffff81526ab9>] SyS_write+0xd9/0x1c0 fs/read_write.c:577
 [<ffffffff838cc865>] entry_SYSCALL_64_fastpath+0x22/0x9e

Allocated by task 23542:
 [<ffffffff81034676>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff814fd823>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512
 [<ffffffff814fdb07>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff814fdb07>] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:616
 [<ffffffff814fe0d2>] kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:554
 [<ffffffff814f9bee>] slab_post_alloc_hook mm/slub.c:1349 [inline]
 [<ffffffff814f9bee>] slab_alloc_node mm/slub.c:2615 [inline]
 [<ffffffff814f9bee>] slab_alloc mm/slub.c:2623 [inline]
 [<ffffffff814f9bee>] kmem_cache_alloc+0xbe/0x2a0 mm/slub.c:2628
 [<ffffffff82fa5b35>] dst_alloc+0xb5/0x1a0 net/core/dst.c:210
 [<ffffffff831f2cc8>] rt_dst_alloc+0x78/0x430 net/ipv4/route.c:1478
 [<ffffffff831fc18c>] __mkroute_output net/ipv4/route.c:2132 [inline]
 [<ffffffff831fc18c>] __ip_route_output_key_hash+0x9ac/0x2380 net/ipv4/route.c:2344
 [<ffffffff831fe639>] __ip_route_output_key include/net/route.h:124 [inline]
 [<ffffffff831fe639>] ip_route_output_flow+0x29/0xa0 net/ipv4/route.c:2431
 [<ffffffff83314342>] ip_route_output_ports include/net/route.h:161 [inline]
 [<ffffffff83314342>] igmpv3_newpack+0x2a2/0xea0 net/ipv4/igmp.c:371
 [<ffffffff83315175>] add_grhead.isra.31+0x235/0x300 net/ipv4/igmp.c:442
 [<ffffffff83315ee0>] add_grec+0xca0/0xf00 net/ipv4/igmp.c:564
 [<ffffffff83318e10>] igmpv3_send_cr net/ipv4/igmp.c:654 [inline]
 [<ffffffff83318e10>] igmp_ifc_timer_expire+0x560/0x8a0 net/ipv4/igmp.c:790
 [<ffffffff81293b2c>] call_timer_fn+0x18c/0x870 kernel/time/timer.c:1185
 [<ffffffff81294852>] __run_timers kernel/time/timer.c:1261 [inline]
 [<ffffffff81294852>] run_timer_softirq+0x642/0xb90 kernel/time/timer.c:1444
 [<ffffffff838cfd7c>] __do_softirq+0x22c/0xa1a kernel/softirq.c:273

Freed by task 14:
 [<ffffffff81034676>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff814fd823>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512
 [<ffffffff814fe152>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff814fe152>] kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:589
 [<ffffffff814fb33e>] slab_free_hook mm/slub.c:1383 [inline]
 [<ffffffff814fb33e>] slab_free_freelist_hook mm/slub.c:1405 [inline]
 [<ffffffff814fb33e>] slab_free mm/slub.c:2859 [inline]
 [<ffffffff814fb33e>] kmem_cache_free+0xbe/0x340 mm/slub.c:2881
 [<ffffffff82fa4de5>] dst_destroy.part.6+0x1f5/0x330 net/core/dst.c:270
 [<ffffffff82fa5465>] dst_destroy net/core/dst.c:252 [inline]
 [<ffffffff82fa5465>] dst_destroy_rcu+0x15/0x40 net/core/dst.c:295
 [<ffffffff81288d97>] __rcu_reclaim kernel/rcu/rcu.h:118 [inline]
 [<ffffffff81288d97>] rcu_do_batch kernel/rcu/tree.c:2705 [inline]
 [<ffffffff81288d97>] invoke_rcu_callbacks kernel/rcu/tree.c:2973 [inline]
 [<ffffffff81288d97>] __rcu_process_callbacks kernel/rcu/tree.c:2940 [inline]
 [<ffffffff81288d97>] rcu_process_callbacks+0x927/0x1440 kernel/rcu/tree.c:2957
 [<ffffffff838cfd7c>] __do_softirq+0x22c/0xa1a kernel/softirq.c:273

The buggy address belongs to the object at ffff8800b94cf640
 which belongs to the cache ip_dst_cache of size 208
The buggy address is located 24 bytes inside of
 208-byte region [ffff8800b94cf640, ffff8800b94cf710)
The buggy address belongs to the page:
BUG: unable to handle kernel paging request at fffffffb8ee97cf8
IP: [<ffffffff81227dd5>] cpuacct_charge+0x155/0x380 kernel/sched/cpuacct.c:247
PGD 440f067 PUD 0 
Oops: 0000 [#1] PREEMPT SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 23878 Comm: syz-executor6 Not tainted 4.4.153-g5e24b4e #90
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d69d9800 task.stack: ffff8801ccdb8000
RIP: 0010:[<ffffffff81227dd5>]  [<ffffffff81227dd5>] cpuacct_charge+0x155/0x380 kernel/sched/cpuacct.c:247
RSP: 0018:ffff8801ccdbf908  EFLAGS: 00010046
RAX: 1ffffffff089521f RBX: 00000000000185a8 RCX: ffffffff84a16740
RDX: fffffbff71dd2f9f RSI: fffffffb8ee97cf8 RDI: ffffffff844a90f8
RBP: ffff8801ccdbf948 R08: ffff8801d69da1a0 R09: 0000000000000001
R10: 0000000000000001 R11: ffff8801d69d9800 R12: ffffffff844a9020
R13: dffffc0000000000 R14: 0000000003a9875f R15: ffffffff814902b7
FS:  0000000001bba940(0063) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffb8ee97cf8 CR3: 00000001d2dc1000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff81227ce0 0000000000000046 0000000000000003 ffff8801d947c860
 ffff8801d947c800 0000000003a9875f ffff8801d947c8b0 0000000000000000
 ffff8801ccdbf990 ffffffff811dc359 0000000000000005 ffff8801db31f558
Call Trace:
 [<ffffffff811dc359>] update_curr+0x2c9/0x6d0 kernel/sched/fair.c:882
 [<ffffffff811e755a>] enqueue_entity kernel/sched/fair.c:3512 [inline]
 [<ffffffff811e755a>] enqueue_task_fair+0x2fa/0x2790 kernel/sched/fair.c:4695
 [<ffffffff811bea3d>] enqueue_task kernel/sched/core.c:858 [inline]
 [<ffffffff811bea3d>] activate_task+0x14d/0x280 kernel/sched/core.c:874
 [<ffffffff811bfa6f>] ttwu_activate kernel/sched/core.c:1736 [inline]
 [<ffffffff811bfa6f>] ttwu_do_activate.constprop.109+0xbf/0x1e0 kernel/sched/core.c:1789
 [<ffffffff811c2c80>] ttwu_queue kernel/sched/core.c:1934 [inline]
 [<ffffffff811c2c80>] try_to_wake_up+0x660/0xf00 kernel/sched/core.c:2068
 [<ffffffff811c36a5>] default_wake_function+0x35/0x50 kernel/sched/core.c:3494
 [<ffffffff8121cff6>] __wake_up_common+0xb6/0x150 kernel/sched/wait.c:73
 [<ffffffff8121d0ee>] __wake_up_locked+0xe/0x10 kernel/sched/wait.c:105
 [<ffffffff815fe8e3>] ep_poll_callback+0x173/0x5b0 fs/eventpoll.c:1065
 [<ffffffff8121cff6>] __wake_up_common+0xb6/0x150 kernel/sched/wait.c:73
 [<ffffffff8121d150>] __wake_up_sync_key+0x40/0x60 kernel/sched/wait.c:145
 [<ffffffff8153cbe5>] pipe_write+0x985/0xd80 fs/pipe.c:469
 [<ffffffff815228cd>] new_sync_write fs/read_write.c:478 [inline]
 [<ffffffff815228cd>] __vfs_write+0x30d/0x3f0 fs/read_write.c:491
 [<ffffffff815244b1>] vfs_write+0x191/0x4e0 fs/read_write.c:538
 [<ffffffff81526ab9>] SYSC_write fs/read_write.c:585 [inline]
 [<ffffffff81526ab9>] SyS_write+0xd9/0x1c0 fs/read_write.c:577
 [<ffffffff838cc865>] entry_SYSCALL_64_fastpath+0x22/0x9e
Code: 49 8d bc 24 d8 00 00 00 48 89 f8 48 c1 e8 03 42 80 3c 28 00 0f 85 c4 01 00 00 49 8b 9c 24 d8 00 00 00 80 3a 00 0f 85 8f 01 00 00 <4a> 03 1c f9 48 89 d8 48 c1 e8 03 42 80 3c 28 00 0f 85 be 01 00 
RIP  [<ffffffff81227dd5>] cpuacct_charge+0x155/0x380 kernel/sched/cpuacct.c:247
 RSP <ffff8801ccdbf908>
CR2: fffffffb8ee97cf8
---[ end trace 2223e938e0c861b6 ]---