==================================================================
BUG: KASAN: slab-out-of-bounds in _decode_session6+0x134a/0x1500 net/ipv6/xfrm6_policy.c:161
Read of size 1 at addr ffff880188cc64c7 by task syz-executor3/30525

CPU: 1 PID: 30525 Comm: syz-executor3 Not tainted 4.19.0+ #135
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x244/0x39d lib/dump_stack.c:113
 print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430
 _decode_session6+0x134a/0x1500 net/ipv6/xfrm6_policy.c:161
 __xfrm_decode_session+0x71/0x140 net/xfrm/xfrm_policy.c:2299
 xfrm_decode_session include/net/xfrm.h:1232 [inline]
 vti_tunnel_xmit+0x1b1/0x1730 net/ipv4/ip_vti.c:252
 __netdev_start_xmit include/linux/netdevice.h:4336 [inline]
 netdev_start_xmit include/linux/netdevice.h:4345 [inline]
 xmit_one net/core/dev.c:3252 [inline]
 dev_hard_start_xmit+0x295/0xc90 net/core/dev.c:3268
 __dev_queue_xmit+0x2f71/0x3ad0 net/core/dev.c:3838
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3871
 __bpf_tx_skb net/core/filter.c:2017 [inline]
 __bpf_redirect_common net/core/filter.c:2055 [inline]
 __bpf_redirect+0x5cf/0xb20 net/core/filter.c:2062
 ____bpf_clone_redirect net/core/filter.c:2095 [inline]
 bpf_clone_redirect+0x2f6/0x490 net/core/filter.c:2067
 bpf_prog_c43b17cda12376d2+0xfc2/0x1000

Allocated by task 30525:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553
 __do_kmalloc mm/slab.c:3718 [inline]
 __kmalloc+0x14e/0x760 mm/slab.c:3727
 kmalloc include/linux/slab.h:518 [inline]
 kzalloc include/linux/slab.h:707 [inline]
 bpf_test_init.isra.10+0x98/0x100 net/bpf/test_run.c:100
 bpf_prog_test_run_skb+0x103/0xcb0 net/bpf/test_run.c:124
 bpf_prog_test_run+0x130/0x1a0 kernel/bpf/syscall.c:1870
 __do_sys_bpf kernel/bpf/syscall.c:2507 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:2451 [inline]
 __x64_sys_bpf+0x3d8/0x520 kernel/bpf/syscall.c:2451
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 29530:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kfree+0xcf/0x230 mm/slab.c:3813
 skb_free_head+0x99/0xc0 net/core/skbuff.c:550
 skb_release_data+0x6a4/0x880 net/core/skbuff.c:570
 skb_release_all+0x4a/0x60 net/core/skbuff.c:627
 __kfree_skb net/core/skbuff.c:641 [inline]
 kfree_skb+0x1bb/0x580 net/core/skbuff.c:659
 vti_xmit net/ipv4/ip_vti.c:232 [inline]
 vti_tunnel_xmit+0xc16/0x1730 net/ipv4/ip_vti.c:264
 __netdev_start_xmit include/linux/netdevice.h:4336 [inline]
 netdev_start_xmit include/linux/netdevice.h:4345 [inline]
 xmit_one net/core/dev.c:3252 [inline]
 dev_hard_start_xmit+0x295/0xc90 net/core/dev.c:3268
 __dev_queue_xmit+0x2f71/0x3ad0 net/core/dev.c:3838
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3871
 __bpf_tx_skb net/core/filter.c:2017 [inline]
 __bpf_redirect_common net/core/filter.c:2055 [inline]
 __bpf_redirect+0x5cf/0xb20 net/core/filter.c:2062
 ____bpf_clone_redirect net/core/filter.c:2095 [inline]
 bpf_clone_redirect+0x2f6/0x490 net/core/filter.c:2067
 bpf_prog_89a4347e47d3f6df+0xa72/0x1000

The buggy address belongs to the object at ffff880188cc62c0
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 7 bytes to the right of
 512-byte region [ffff880188cc62c0, ffff880188cc64c0)
The buggy address belongs to the page:
page:ffffea0006233180 count:1 mapcount:0 mapping:ffff8801da800940 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffffea0006580148 ffffea0007183cc8 ffff8801da800940
raw: 0000000000000000 ffff880188cc6040 0000000100000006 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff880188cc6380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff880188cc6400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff880188cc6480: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
                                           ^
 ffff880188cc6500: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
 ffff880188cc6580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================