random: sshd: uninitialized urandom read (32 bytes read, 117 bits of entropy available)
==================================================================
BUG: KASAN: use-after-free in ip6_dst_idev include/net/ip6_fib.h:141 [inline]
BUG: KASAN: use-after-free in ip6_xmit+0x193a/0x1ad0 net/ipv6/ip6_output.c:237
Read of size 8 at addr ffff8801d58e03d8 by task syzkaller880654/3328

CPU: 0 PID: 3328 Comm: syzkaller880654 Not tainted 4.4.112-g3fc4284 #32
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 822461627fab6c6f ffff8801d0a775b8 ffffffff81d054ed
 ffffea0007563800 ffff8801d58e03d8 0000000000000000 ffff8801d58e03d8
 0000000000000040 ffff8801d0a775f0 ffffffff814fd953 ffff8801d58e03d8
Call Trace:
 [<ffffffff81d054ed>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d054ed>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff814fd953>] print_address_description+0x73/0x260 mm/kasan/report.c:252
 [<ffffffff814fde65>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff814fde65>] kasan_report+0x285/0x370 mm/kasan/report.c:408
 [<ffffffff814fdfc4>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:429
 [<ffffffff83307d0a>] ip6_dst_idev include/net/ip6_fib.h:141 [inline]
 [<ffffffff83307d0a>] ip6_xmit+0x193a/0x1ad0 net/ipv6/ip6_output.c:237
 [<ffffffff833c8b56>] inet6_csk_xmit+0x246/0x480 net/ipv6/inet6_connection_sock.c:176
 [<ffffffff8345b1ff>] l2tp_xmit_core net/l2tp/l2tp_core.c:1084 [inline]
 [<ffffffff8345b1ff>] l2tp_xmit_skb+0xc2f/0xea0 net/l2tp/l2tp_core.c:1179
 [<ffffffff83467ce4>] pppol2tp_sendmsg+0x584/0x7f0 net/l2tp/l2tp_ppp.c:355
 [<ffffffff82dee20a>] sock_sendmsg_nosec net/socket.c:625 [inline]
 [<ffffffff82dee20a>] sock_sendmsg+0xca/0x110 net/socket.c:635
 [<ffffffff82defa32>] ___sys_sendmsg+0x312/0x7c0 net/socket.c:1962
 [<ffffffff82df205c>] __sys_sendmmsg+0x11c/0x2e0 net/socket.c:2047
 [<ffffffff82df2255>] SYSC_sendmmsg net/socket.c:2077 [inline]
 [<ffffffff82df2255>] SyS_sendmmsg+0x35/0x60 net/socket.c:2072
 [<ffffffff837761d9>] entry_SYSCALL_64_fastpath+0x16/0x92

Allocated by task 3272:
 [<ffffffff81035df6>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff814fc9c3>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512
 [<ffffffff814fcc8d>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff814fcc8d>] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:616
 [<ffffffff814fd262>] kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:554
 [<ffffffff814f892a>] slab_post_alloc_hook mm/slub.c:1349 [inline]
 [<ffffffff814f892a>] slab_alloc_node mm/slub.c:2615 [inline]
 [<ffffffff814f892a>] slab_alloc mm/slub.c:2623 [inline]
 [<ffffffff814f892a>] kmem_cache_alloc+0xba/0x290 mm/slub.c:2628
 [<ffffffff82e6bbff>] dst_alloc+0x11f/0x1a0 net/core/dst.c:210
 [<ffffffff830c42c8>] rt_dst_alloc+0x78/0x430 net/ipv4/route.c:1467
 [<ffffffff830cd6ae>] __mkroute_output net/ipv4/route.c:2120 [inline]
 [<ffffffff830cd6ae>] __ip_route_output_key_hash+0xa4e/0x2390 net/ipv4/route.c:2332
 [<ffffffff83197945>] __ip_route_output_key include/net/route.h:123 [inline]
 [<ffffffff83197945>] ip_route_connect include/net/route.h:296 [inline]
 [<ffffffff83197945>] __ip4_datagram_connect+0xa15/0x1150 net/ipv4/datagram.c:51
 [<ffffffff833b9b69>] __ip6_datagram_connect+0x4d9/0x1950 net/ipv6/datagram.c:59
 [<ffffffff833bb00f>] ip6_datagram_connect+0x2f/0x50 net/ipv6/datagram.c:223
 [<ffffffff831d231b>] inet_dgram_connect+0x16b/0x1f0 net/ipv4/af_inet.c:550
 [<ffffffff82deed36>] SYSC_connect+0x1b6/0x310 net/socket.c:1557
 [<ffffffff82df15a4>] SyS_connect+0x24/0x30 net/socket.c:1538
 [<ffffffff837761d9>] entry_SYSCALL_64_fastpath+0x16/0x92

Freed by task 3198:
 [<ffffffff81035df6>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff814fc9c3>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512
 [<ffffffff814fd2e2>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff814fd2e2>] kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:589
 [<ffffffff814f9a17>] slab_free_hook mm/slub.c:1383 [inline]
 [<ffffffff814f9a17>] slab_free_freelist_hook mm/slub.c:1405 [inline]
 [<ffffffff814f9a17>] slab_free mm/slub.c:2859 [inline]
 [<ffffffff814f9a17>] kmem_cache_free+0xc7/0x320 mm/slub.c:2881
 [<ffffffff82e6c89e>] dst_destroy+0x20e/0x330 net/core/dst.c:270
 [<ffffffff82e6cee5>] dst_destroy_rcu+0x15/0x40 net/core/dst.c:295
 [<ffffffff81294128>] __rcu_reclaim kernel/rcu/rcu.h:118 [inline]
 [<ffffffff81294128>] rcu_do_batch kernel/rcu/tree.c:2705 [inline]
 [<ffffffff81294128>] invoke_rcu_callbacks kernel/rcu/tree.c:2973 [inline]
 [<ffffffff81294128>] __rcu_process_callbacks kernel/rcu/tree.c:2940 [inline]
 [<ffffffff81294128>] rcu_process_callbacks+0x7f8/0x14b0 kernel/rcu/tree.c:2957
 [<ffffffff837796fd>] __do_softirq+0x24d/0xa59 kernel/softirq.c:273

The buggy address belongs to the object at ffff8801d58e03c0
 which belongs to the cache ip_dst_cache of size 208
The buggy address is located 24 bytes inside of
 208-byte region [ffff8801d58e03c0, ffff8801d58e0490)
The buggy address belongs to the page:
PANIC: double fault, error_code: 0x0
CPU: 0 PID: 3328 Comm: syzkaller880654 Not tainted 4.4.112-g3fc4284 #32
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8800b5f9df00 task.stack: ffff8801d0a70000
RIP: 0010:[<ffffffff8148fd2d>]  [<ffffffff8148fd2d>] dump_page_badflags+0xd/0x250 mm/debug.c:84
RSP: 0018:ffff880100000000  EFLAGS: 00010046
RAX: ffff8800b5f9df00 RBX: ffffea0007563800 RCX: ffffffff8148fea0
RDX: 0000000000000000 RSI: ffffffff838a8620 RDI: ffffea0007563800
RBP: ffff880100000018 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000002 R11: fffffbfff0ad7a1e R12: 0000000000000000
R13: ffffffff838a8620 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000e69880(0063) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff8800fffffff8 CR3: 00000001d0ed6000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:

Call Trace:
 <UNK> 
Code: ff e8 a8 e2 06 00 e9 50 fd ff ff e8 9e e2 06 00 e9 1d fd ff ff 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 57 41 56 41 55 49 89 f5 <41> 54 49 89 d4 53 48 89 fb 48 83 ec 08 e8 11 01 ed ff 48 8d 7b