==================================================================
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 ffff8800baa7fb58 by task syz-executor5/10112

CPU: 1 PID: 10112 Comm: syz-executor5 Not tainted 4.4.150-g5541782 #83
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 f549317003ac2b5b ffff8801b760f5c8 ffffffff81e14e2d
 ffffea0002ea9fc0 ffff8800baa7fb58 0000000000000000 ffff8800baa7fb58
 0000000000001200 ffff8801b760f600 ffffffff8151a3f0 ffff8800baa7fb58
Call Trace:
 [<ffffffff81e14e2d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81e14e2d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff8151a3f0>] print_address_description+0x6c/0x216 mm/kasan/report.c:252
 [<ffffffff8151a70f>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff8151a70f>] kasan_report.cold.7+0x175/0x2f7 mm/kasan/report.c:408
 [<ffffffff814fdca4>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:429
 [<ffffffff83434bcc>] ip6_dst_idev include/net/ip6_fib.h:141 [inline]
 [<ffffffff83434bcc>] ip6_xmit+0x177c/0x1a00 net/ipv6/ip6_output.c:237
 [<ffffffff834f4c15>] inet6_csk_xmit+0x245/0x490 net/ipv6/inet6_connection_sock.c:176
 [<ffffffff835a425b>] l2tp_xmit_core net/l2tp/l2tp_core.c:1084 [inline]
 [<ffffffff835a425b>] l2tp_xmit_skb+0xbeb/0xeb0 net/l2tp/l2tp_core.c:1179
 [<ffffffff835b0790>] pppol2tp_sendmsg+0x4e0/0x7d0 net/l2tp/l2tp_ppp.c:355
 [<ffffffff82f25d2c>] sock_sendmsg_nosec net/socket.c:626 [inline]
 [<ffffffff82f25d2c>] sock_sendmsg+0xcc/0x110 net/socket.c:636
 [<ffffffff82f274f1>] ___sys_sendmsg+0x441/0x880 net/socket.c:1963
 [<ffffffff82f29ace>] __sys_sendmmsg+0x12e/0x2e0 net/socket.c:2048
 [<ffffffff82f29cb5>] SYSC_sendmmsg net/socket.c:2078 [inline]
 [<ffffffff82f29cb5>] SyS_sendmmsg+0x35/0x60 net/socket.c:2073
 [<ffffffff838cb0a5>] entry_SYSCALL_64_fastpath+0x22/0x9e

Allocated by task 9015:
 [<ffffffff81034676>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff814fcd53>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512
 [<ffffffff814fd037>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff814fd037>] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:616
 [<ffffffff814fd602>] kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:554
 [<ffffffff814f911e>] slab_post_alloc_hook mm/slub.c:1349 [inline]
 [<ffffffff814f911e>] slab_alloc_node mm/slub.c:2615 [inline]
 [<ffffffff814f911e>] slab_alloc mm/slub.c:2623 [inline]
 [<ffffffff814f911e>] kmem_cache_alloc+0xbe/0x2a0 mm/slub.c:2628
 [<ffffffff82fa4295>] dst_alloc+0xb5/0x1a0 net/core/dst.c:210
 [<ffffffff831f1428>] rt_dst_alloc+0x78/0x430 net/ipv4/route.c:1478
 [<ffffffff831fa8ec>] __mkroute_output net/ipv4/route.c:2132 [inline]
 [<ffffffff831fa8ec>] __ip_route_output_key_hash+0x9ac/0x2380 net/ipv4/route.c:2344
 [<ffffffff831fcd99>] __ip_route_output_key include/net/route.h:124 [inline]
 [<ffffffff831fcd99>] ip_route_output_flow+0x29/0xa0 net/ipv4/route.c:2431
 [<ffffffff832d9270>] udp_sendmsg+0x1480/0x1c70 net/ipv4/udp.c:1040
 [<ffffffff8349e89d>] udpv6_sendmsg+0x12cd/0x24c0 net/ipv6/udp.c:1173
 [<ffffffff833090e3>] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:755
 [<ffffffff82f25d2c>] sock_sendmsg_nosec net/socket.c:626 [inline]
 [<ffffffff82f25d2c>] sock_sendmsg+0xcc/0x110 net/socket.c:636
 [<ffffffff82f26a0c>] SYSC_sendto+0x21c/0x370 net/socket.c:1666
 [<ffffffff82f29090>] SyS_sendto+0x40/0x50 net/socket.c:1634
 [<ffffffff838cb0a5>] entry_SYSCALL_64_fastpath+0x22/0x9e

Freed by task 9017:
 [<ffffffff81034676>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff814fcd53>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512
 [<ffffffff814fd682>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff814fd682>] kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:589
 [<ffffffff814fa86e>] slab_free_hook mm/slub.c:1383 [inline]
 [<ffffffff814fa86e>] slab_free_freelist_hook mm/slub.c:1405 [inline]
 [<ffffffff814fa86e>] slab_free mm/slub.c:2859 [inline]
 [<ffffffff814fa86e>] kmem_cache_free+0xbe/0x340 mm/slub.c:2881
 [<ffffffff82fa3545>] dst_destroy.part.6+0x1f5/0x330 net/core/dst.c:270
 [<ffffffff82fa3bc5>] dst_destroy net/core/dst.c:252 [inline]
 [<ffffffff82fa3bc5>] dst_destroy_rcu+0x15/0x40 net/core/dst.c:295
 [<ffffffff81288ce7>] __rcu_reclaim kernel/rcu/rcu.h:118 [inline]
 [<ffffffff81288ce7>] rcu_do_batch kernel/rcu/tree.c:2705 [inline]
 [<ffffffff81288ce7>] invoke_rcu_callbacks kernel/rcu/tree.c:2973 [inline]
 [<ffffffff81288ce7>] __rcu_process_callbacks kernel/rcu/tree.c:2940 [inline]
 [<ffffffff81288ce7>] rcu_process_callbacks+0x927/0x1440 kernel/rcu/tree.c:2957
 [<ffffffff838ce5bc>] __do_softirq+0x22c/0xa1a kernel/softirq.c:273

The buggy address belongs to the object at ffff8800baa7fb40
 which belongs to the cache ip_dst_cache of size 208
The buggy address is located 24 bytes inside of
 208-byte region [ffff8800baa7fb40, ffff8800baa7fc10)
The buggy address belongs to the page:
BUG: unable to handle kernel paging request at fffffffba1f6d980
IP: [<ffffffff81227c65>] 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: 3821 Comm: syz-executor5 Not tainted 4.4.150-g5541782 #83
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8800bb329800 task.stack: ffff8801bf958000
RIP: 0010:[<ffffffff81227c65>]  [<ffffffff81227c65>] cpuacct_charge+0x155/0x380 kernel/sched/cpuacct.c:247
RSP: 0018:ffff8801bf95f8b8  EFLAGS: 00010046
RAX: 1ffffffff089521f RBX: 00000000000185a8 RCX: ffffffff84a16680
RDX: fffffbff743edb30 RSI: fffffffba1f6d980 RDI: ffffffff844a90f8
RBP: ffff8801bf95f8f8 R08: ffff8800bb32a1c8 R09: 0000000000000001
R10: 0000000000000001 R11: ffff8800bb329800 R12: ffffffff844a9020
R13: dffffc0000000000 R14: 000000000dd79e3f R15: ffffffff83aaae60
FS:  0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffba1f6d980 CR3: 000000000440c000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff81227b70 0000000000000046 0000000000000003 ffff8801beb54860
 ffff8801beb54800 000000000dd79e3f ffff8801beb548b0 0000000000000000
 ffff8801bf95f940 ffffffff811dc1e9 0000000000000005 ffff8801db31f558
Call Trace:
 [<ffffffff811dc1e9>] update_curr+0x2c9/0x6d0 kernel/sched/fair.c:882
 [<ffffffff811e73ea>] enqueue_entity kernel/sched/fair.c:3512 [inline]
 [<ffffffff811e73ea>] enqueue_task_fair+0x2fa/0x2790 kernel/sched/fair.c:4695
 [<ffffffff811be8cd>] enqueue_task kernel/sched/core.c:858 [inline]
 [<ffffffff811be8cd>] activate_task+0x14d/0x280 kernel/sched/core.c:874
 [<ffffffff811bf8ff>] ttwu_activate kernel/sched/core.c:1736 [inline]
 [<ffffffff811bf8ff>] ttwu_do_activate.constprop.109+0xbf/0x1e0 kernel/sched/core.c:1789
 [<ffffffff811c2b10>] ttwu_queue kernel/sched/core.c:1934 [inline]
 [<ffffffff811c2b10>] try_to_wake_up+0x660/0xf00 kernel/sched/core.c:2068
 [<ffffffff811c5660>] wake_up_state+0x10/0x20 kernel/sched/core.c:2148
 [<ffffffff811589e4>] signal_wake_up_state+0x44/0x70 kernel/signal.c:659
 [<ffffffff8115907b>] signal_wake_up include/linux/sched.h:3332 [inline]
 [<ffffffff8115907b>] complete_signal+0x62b/0x790 kernel/signal.c:942
 [<ffffffff8115a5c5>] __send_signal+0x4d5/0x11b0 kernel/signal.c:1080
 [<ffffffff8115b2ea>] send_signal+0x4a/0xc0 kernel/signal.c:1096
 [<ffffffff8115d9d4>] do_send_sig_info+0xa4/0x130 kernel/signal.c:1151
 [<ffffffff8115da93>] send_sig_info+0x33/0x50 kernel/signal.c:1436
 [<ffffffff81329b8d>] zap_pid_ns_processes+0x28d/0x690 kernel/pid_namespace.c:223
 [<ffffffff811393d1>] find_child_reaper kernel/exit.c:477 [inline]
 [<ffffffff811393d1>] forget_original_parent kernel/exit.c:563 [inline]
 [<ffffffff811393d1>] exit_notify kernel/exit.c:599 [inline]
 [<ffffffff811393d1>] do_exit+0x1c21/0x26b0 kernel/exit.c:776
 [<ffffffff8113e0d1>] do_group_exit+0x111/0x330 kernel/exit.c:885
 [<ffffffff8113e30d>] SYSC_exit_group kernel/exit.c:896 [inline]
 [<ffffffff8113e30d>] SyS_exit_group+0x1d/0x20 kernel/exit.c:894
 [<ffffffff838cb0a5>] 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  [<ffffffff81227c65>] cpuacct_charge+0x155/0x380 kernel/sched/cpuacct.c:247
 RSP <ffff8801bf95f8b8>
CR2: fffffffba1f6d980
---[ end trace 23e1a93f2b61ce70 ]---