==================================================================
BUG: KASAN: slab-out-of-bounds in ip6_dst_idev include/net/ip6_fib.h:141 [inline]
BUG: KASAN: slab-out-of-bounds in ip6_xmit+0x177c/0x1a00 net/ipv6/ip6_output.c:237
Read of size 8 at addr ffff8801d3d55158 by task syz-executor0/6194

CPU: 1 PID: 6194 Comm: syz-executor0 Not tainted 4.4.153-g5e24b4e #26
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 36ac068e7208e816 ffff8800a1797548 ffffffff81e162ed
 ffffea00074f5540 ffff8801d3d55158 0000000000000000 ffff8801d3d55158
 0000000000001000 ffff8800a1797580 ffffffff8151b4d9 ffff8801d3d55158
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
 [<ffffffff82f28d41>] ___sys_sendmsg+0x441/0x880 net/socket.c:1975
 [<ffffffff82f2b3d4>] __sys_sendmmsg+0x1d4/0x2e0 net/socket.c:2053
 [<ffffffff83014e22>] C_SYSC_sendmmsg net/compat.c:728 [inline]
 [<ffffffff83014e22>] compat_SyS_sendmmsg+0x32/0x40 net/compat.c:725
 [<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
 [<ffffffff838ce1c3>] sysenter_flags_fixed+0xd/0x1a

Allocated by task 0:
(stack is not available)

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff8801d3d55140
 which belongs to the cache ip_dst_cache of size 208
The buggy address is located 24 bytes inside of
 208-byte region [ffff8801d3d55140, ffff8801d3d55210)
The buggy address belongs to the page:
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 6227 Comm: syz-executor7 Not tainted 4.4.153-g5e24b4e #26
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801ce180000 task.stack: ffff8801ba800000
RIP: 0010:[<ffffffff81e271b4>]  [<ffffffff81e271b4>] rb_set_parent_color include/linux/rbtree_augmented.h:117 [inline]
RIP: 0010:[<ffffffff81e271b4>]  [<ffffffff81e271b4>] ____rb_erase_color lib/rbtree.c:256 [inline]
RIP: 0010:[<ffffffff81e271b4>]  [<ffffffff81e271b4>] rb_erase+0x4f4/0x1cb0 lib/rbtree.c:429
RSP: 0018:ffff8801db207cf8  EFLAGS: 00010082
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff8801db219cc8
RDX: ffffed003b6432f2 RSI: ffff8801db219790 RDI: 0000000000000000
RBP: ffff8801db207d40 R08: ffffffff85356280 R09: 0000000000000001
R10: 0000000000000000 R11: ffff8801ce180000 R12: ffff8801db219cc0
R13: ffff8801d3d55210 R14: ffff8801db219cc1 R15: ffff8801d3d55220
FS:  0000000000000000(0000) GS:ffff8801db200000(0063) knlGS:00000000f5781b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 000000002c824000 CR3: 00000000ae013000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffed003b6432f2 ffff8801db219cc8 ffff8801db219790 0000000000000000
 ffff8801c2c1fd28 ffff8801db219790 ffff8801db219798 0000000000000000
 0000000000000000 ffff8801db207d70 ffffffff81e33f48 ffffffff844bec20
Call Trace:
 <IRQ> 
 [<ffffffff81e33f48>] timerqueue_del+0x78/0x170 lib/timerqueue.c:86
 [<ffffffff8129ecee>] __remove_hrtimer+0x8e/0x250 kernel/time/hrtimer.c:917
 [<ffffffff812a0d1d>] __run_hrtimer kernel/time/hrtimer.c:1242 [inline]
 [<ffffffff812a0d1d>] __hrtimer_run_queues+0x2dd/0x1000 kernel/time/hrtimer.c:1325
 [<ffffffff812a2561>] hrtimer_interrupt+0x1b1/0x430 kernel/time/hrtimer.c:1359
 [<ffffffff810af544>] local_apic_timer_interrupt+0x74/0xa0 arch/x86/kernel/apic/apic.c:901
 [<ffffffff838cf4dc>] smp_apic_timer_interrupt+0x7c/0xa0 arch/x86/kernel/apic/apic.c:925
 [<ffffffff838ce420>] apic_timer_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:741
 <EOI> 
 [<ffffffff81e75fac>] debug_smp_processor_id+0x1c/0x20 lib/smp_processor_id.c:56
 [<ffffffff81282c0c>] rcu_lockdep_current_cpu_online+0x3c/0x140 kernel/rcu/tree.c:1051
 [<ffffffff8127a7d0>] rcu_read_lock_held+0x90/0xc0 kernel/rcu/update.c:273
 [<ffffffff8157e705>] fcheck_files include/linux/fdtable.h:94 [inline]
 [<ffffffff8157e705>] __fget+0x295/0x3b0 fs/file.c:700
 [<ffffffff8157e838>] fget+0x18/0x20 fs/file.c:718
 [<ffffffff82f234c8>] sockfd_lookup+0x18/0x150 net/socket.c:437
 [<ffffffff83014901>] C_SYSC_setsockopt net/compat.c:372 [inline]
 [<ffffffff83014901>] compat_SyS_setsockopt+0x91/0x2a0 net/compat.c:368
 [<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
 [<ffffffff838ce1c3>] sysenter_flags_fixed+0xd/0x1a
Code: 14 00 00 4c 89 ff 49 89 44 24 08 48 c1 ef 03 80 3c 1f 00 0f 85 7c 14 00 00 48 89 c7 4d 89 e6 4d 89 65 10 48 c1 ef 03 49 83 ce 01 <80> 3c 1f 00 0f 85 8d 14 00 00 4c 89 e7 4c 89 30 48 c1 ef 03 80 
RIP  [<ffffffff81e271b4>] rb_set_parent_color include/linux/rbtree_augmented.h:117 [inline]
RIP  [<ffffffff81e271b4>] ____rb_erase_color lib/rbtree.c:256 [inline]
RIP  [<ffffffff81e271b4>] rb_erase+0x4f4/0x1cb0 lib/rbtree.c:429
 RSP <ffff8801db207cf8>
---[ end trace b68c08501f183e02 ]---