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BUG: KASAN: use-after-free in _decode_session6+0x134a/0x1500 net/ipv6/xfrm6_policy.c:161
Read of size 1 at addr ffff88018ea2ea7f by task syz-executor1/10784

CPU: 0 PID: 10784 Comm: syz-executor1 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]
 vti6_tnl_xmit+0x3fc/0x1c10 net/ipv6/ip6_vti.c:542
 __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_c39d1ba309a769f7+0x802/0x1000

Allocated by task 10543:
 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_node mm/slab.c:3682 [inline]
 __kmalloc_node_track_caller+0x47/0x70 mm/slab.c:3696
 __kmalloc_reserve.isra.40+0x41/0xe0 net/core/skbuff.c:137
 __alloc_skb+0x155/0x770 net/core/skbuff.c:205
 alloc_skb include/linux/skbuff.h:997 [inline]
 ip_do_fragment+0xbcf/0x2ad0 net/ipv4/ip_output.c:742
 ip_fragment.constprop.50+0x179/0x240 net/ipv4/ip_output.c:549
 ip_finish_output+0x6b4/0xfa0 net/ipv4/ip_output.c:315
 NF_HOOK_COND include/linux/netfilter.h:278 [inline]
 ip_mc_output+0x2c4/0x15b0 net/ipv4/ip_output.c:390
 dst_output include/net/dst.h:444 [inline]
 ip_local_out+0xc5/0x1b0 net/ipv4/ip_output.c:124
 iptunnel_xmit+0x56a/0x8d0 net/ipv4/ip_tunnel_core.c:91
 ip_tunnel_xmit+0x15b8/0x3c04 net/ipv4/ip_tunnel.c:787
 __gre_xmit+0x5e1/0x980 net/ipv4/ip_gre.c:451
 ipgre_xmit+0x3e7/0xba0 net/ipv4/ip_gre.c:705
 __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
 0xffffffffa0030f37

Freed by task 10543:
 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
 kfree_skb_list net/core/skbuff.c:668 [inline]
 skb_release_data+0x4af/0x880 net/core/skbuff.c:567
 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
 ip_rcv_finish_core.isra.16+0xd1d/0x1f40 net/ipv4/ip_input.c:393
 ip_rcv_finish+0xc6/0x300 net/ipv4/ip_input.c:413
 NF_HOOK include/linux/netfilter.h:289 [inline]
 ip_rcv+0xed/0x600 net/ipv4/ip_input.c:524
 __netif_receive_skb_one_core+0x14d/0x200 net/core/dev.c:4941
 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:5051
 process_backlog+0x24e/0x7a0 net/core/dev.c:5855
 napi_poll net/core/dev.c:6275 [inline]
 net_rx_action+0x7fa/0x19b0 net/core/dev.c:6341
 __do_softirq+0x308/0xb7e kernel/softirq.c:292

The buggy address belongs to the object at ffff88018ea2ea00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 127 bytes inside of
 512-byte region [ffff88018ea2ea00, ffff88018ea2ec00)
The buggy address belongs to the page:
page:ffffea00063a8b80 count:1 mapcount:0 mapping:ffff8801da800940 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffffea0007181ec8 ffffea0006f03808 ffff8801da800940
raw: 0000000000000000 ffff88018ea2e000 0000000100000006 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88018ea2e900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88018ea2e980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88018ea2ea00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                                ^
 ffff88018ea2ea80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88018ea2eb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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