==================================================================
BUG: KASAN: slab-out-of-bounds in pfkey_msg2xfrm_state net/key/af_key.c:1227 [inline]
BUG: KASAN: slab-out-of-bounds in pfkey_add+0x1481/0x3230 net/key/af_key.c:1506
Read of size 8192 at addr ffff8801b5ec3418 by task syz-executor0/16272

CPU: 0 PID: 16272 Comm: syz-executor0 Not tainted 4.9.107-gdb2c520 #49
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801c5e776d0 ffffffff81eb3da9 ffffea0006d7b080 ffff8801b5ec3418
 0000000000000000 ffff8801b5ec3600 ffff8801b5ec3400 ffff8801c5e77708
 ffffffff815679f9 ffff8801b5ec3418 0000000000002000 0000000000000000
Call Trace:
 [<ffffffff81eb3da9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb3da9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff815679f9>] print_address_description+0x6c/0x234 mm/kasan/report.c:256
 [<ffffffff81567e03>] kasan_report_error mm/kasan/report.c:355 [inline]
 [<ffffffff81567e03>] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412
 [<ffffffff8153a8bf>] check_memory_region_inline mm/kasan/kasan.c:318 [inline]
 [<ffffffff8153a8bf>] check_memory_region+0x14f/0x1b0 mm/kasan/kasan.c:325
 [<ffffffff8153af03>] memcpy+0x23/0x50 mm/kasan/kasan.c:360
 [<ffffffff836af681>] pfkey_msg2xfrm_state net/key/af_key.c:1227 [inline]
 [<ffffffff836af681>] pfkey_add+0x1481/0x3230 net/key/af_key.c:1506
 [<ffffffff836a6e91>] pfkey_process+0x671/0x740 net/key/af_key.c:2834
 [<ffffffff836a86b6>] pfkey_sendmsg+0x346/0xae0 net/key/af_key.c:3678
 [<ffffffff83016fcc>] sock_sendmsg_nosec net/socket.c:635 [inline]
 [<ffffffff83016fcc>] sock_sendmsg+0xcc/0x110 net/socket.c:645
 [<ffffffff83018a6c>] ___sys_sendmsg+0x6fc/0x840 net/socket.c:1969
 [<ffffffff8301aad9>] __sys_sendmsg+0xd9/0x190 net/socket.c:2003
 [<ffffffff8311c80a>] C_SYSC_sendmsg net/compat.c:736 [inline]
 [<ffffffff8311c80a>] compat_SyS_sendmsg+0x2a/0x40 net/compat.c:734
 [<ffffffff81006da7>] do_syscall_32_irqs_on arch/x86/entry/common.c:325 [inline]
 [<ffffffff81006da7>] do_fast_syscall_32+0x2f7/0x870 arch/x86/entry/common.c:387
 [<ffffffff839fb210>] entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137

Allocated by task 16272:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
 save_stack+0x43/0xd0 mm/kasan/kasan.c:505
 set_track mm/kasan/kasan.c:517 [inline]
 kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:609
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:547
 slab_post_alloc_hook mm/slab.h:417 [inline]
 slab_alloc_node mm/slub.c:2715 [inline]
 slab_alloc mm/slub.c:2723 [inline]
 __kmalloc_track_caller+0xdc/0x2b0 mm/slub.c:4232
 __kmalloc_reserve.isra.37+0x33/0xc0 net/core/skbuff.c:138
 __alloc_skb+0x11a/0x600 net/core/skbuff.c:231
 alloc_skb include/linux/skbuff.h:919 [inline]
 pfkey_sendmsg+0xfe/0xae0 net/key/af_key.c:3665
 sock_sendmsg_nosec net/socket.c:635 [inline]
 sock_sendmsg+0xcc/0x110 net/socket.c:645
 ___sys_sendmsg+0x6fc/0x840 net/socket.c:1969
 __sys_sendmsg+0xd9/0x190 net/socket.c:2003
 C_SYSC_sendmsg net/compat.c:736 [inline]
 compat_SyS_sendmsg+0x2a/0x40 net/compat.c:734
 do_syscall_32_irqs_on arch/x86/entry/common.c:325 [inline]
 do_fast_syscall_32+0x2f7/0x870 arch/x86/entry/common.c:387
 entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137

Freed by task 14714:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
 save_stack+0x43/0xd0 mm/kasan/kasan.c:505
 set_track mm/kasan/kasan.c:517 [inline]
 kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:582
 slab_free_hook mm/slub.c:1355 [inline]
 slab_free_freelist_hook mm/slub.c:1377 [inline]
 slab_free mm/slub.c:2958 [inline]
 kfree+0xfb/0x310 mm/slub.c:3878
 skb_free_head+0x8b/0xb0 net/core/skbuff.c:580
 pskb_expand_head+0x457/0x930 net/core/skbuff.c:1245
 __skb_cow include/linux/skbuff.h:2727 [inline]
 skb_cow_head include/linux/skbuff.h:2761 [inline]
 l2tp_xmit_skb+0xab4/0xf60 net/l2tp/l2tp_core.c:1219
 pppol2tp_sendmsg+0x4e0/0x790 net/l2tp/l2tp_ppp.c:339
 sock_sendmsg_nosec net/socket.c:635 [inline]
 sock_sendmsg+0xcc/0x110 net/socket.c:645
 ___sys_sendmsg+0x47a/0x840 net/socket.c:1969
 __sys_sendmmsg+0x23c/0x3d0 net/socket.c:2052
 C_SYSC_sendmmsg net/compat.c:742 [inline]
 compat_SyS_sendmmsg+0x32/0x40 net/compat.c:739
 do_syscall_32_irqs_on arch/x86/entry/common.c:325 [inline]
 do_fast_syscall_32+0x2f7/0x870 arch/x86/entry/common.c:387
 entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137

The buggy address belongs to the object at ffff8801b5ec3400
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 24 bytes inside of
 512-byte region [ffff8801b5ec3400, ffff8801b5ec3600)
The buggy address belongs to the page:
page:ffffea0006d7b080 count:1 mapcount:0 mapping:          (null) index:0x0 compound_mapcount: 0
flags: 0x8000000000004080(slab|head)
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801b5ec3500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801b5ec3580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801b5ec3600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff8801b5ec3680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801b5ec3700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================