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BUG: KASAN: use-after-free in decode_session6+0x10e1/0x1950 net/xfrm/xfrm_policy.c:3460
Read of size 1 at addr ffff88802d9c8eeb by task syz-executor.5/30162

CPU: 1 PID: 30162 Comm: syz-executor.5 Not tainted 6.5.0-syzkaller-03967-gbd6c11bc43c4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xc4/0x620 mm/kasan/report.c:475
 kasan_report+0xda/0x110 mm/kasan/report.c:588
 decode_session6+0x10e1/0x1950 net/xfrm/xfrm_policy.c:3460
 __xfrm_decode_session+0x54/0xb0 net/xfrm/xfrm_policy.c:3566
 xfrm_decode_session_reverse include/net/xfrm.h:1223 [inline]
 icmpv6_route_lookup+0x397/0x550 net/ipv6/icmp.c:388
 icmp6_send+0x11c1/0x2720 net/ipv6/icmp.c:595
 __icmpv6_send include/linux/icmpv6.h:28 [inline]
 icmpv6_send include/linux/icmpv6.h:49 [inline]
 ip6_link_failure+0x31/0x5a0 net/ipv6/route.c:2784
 dst_link_failure include/net/dst.h:437 [inline]
 ip6_tnl_xmit+0x4f9/0x3950 net/ipv6/ip6_tunnel.c:1268
 ipxip6_tnl_xmit net/ipv6/ip6_tunnel.c:1384 [inline]
 ip6_tnl_start_xmit+0x6ef/0x1750 net/ipv6/ip6_tunnel.c:1432
 __netdev_start_xmit include/linux/netdevice.h:4889 [inline]
 netdev_start_xmit include/linux/netdevice.h:4903 [inline]
 xmit_one net/core/dev.c:3544 [inline]
 dev_hard_start_xmit+0x13d/0x6c0 net/core/dev.c:3560
 sch_direct_xmit+0x1ac/0xc20 net/sched/sch_generic.c:342
 qdisc_restart net/sched/sch_generic.c:407 [inline]
 __qdisc_run+0x540/0x19d0 net/sched/sch_generic.c:415
 __dev_xmit_skb net/core/dev.c:3834 [inline]
 __dev_queue_xmit+0x24f9/0x3d80 net/core/dev.c:4306
 dev_queue_xmit include/linux/netdevice.h:3082 [inline]
 neigh_connected_output+0x42c/0x5d0 net/core/neighbour.c:1581
 neigh_output include/net/neighbour.h:542 [inline]
 ip6_finish_output2+0x610/0x1b20 net/ipv6/ip6_output.c:135
 __ip6_finish_output net/ipv6/ip6_output.c:196 [inline]
 ip6_finish_output+0x485/0x1250 net/ipv6/ip6_output.c:207
 NF_HOOK_COND include/linux/netfilter.h:293 [inline]
 ip6_output+0x23a/0x880 net/ipv6/ip6_output.c:228
 dst_output include/net/dst.h:458 [inline]
 ip6_local_out+0xaf/0x190 net/ipv6/output_core.c:155
 ip6_send_skb+0xb7/0x330 net/ipv6/ip6_output.c:2018
 ip6_push_pending_frames+0xe0/0x100 net/ipv6/ip6_output.c:2038
 icmpv6_push_pending_frames+0x2da/0x460 net/ipv6/icmp.c:307
 ping_v6_sendmsg+0x104d/0x1420 net/ipv6/ping.c:186
 inet_sendmsg+0x9d/0xe0 net/ipv4/af_inet.c:840
 sock_sendmsg_nosec net/socket.c:728 [inline]
 sock_sendmsg+0xd9/0x180 net/socket.c:751
 __sys_sendto+0x255/0x340 net/socket.c:2174
 __do_sys_sendto net/socket.c:2186 [inline]
 __se_sys_sendto net/socket.c:2182 [inline]
 __x64_sys_sendto+0xe0/0x1b0 net/socket.c:2182
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fd343e7cae9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd344bec0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fd343f9bf80 RCX: 00007fd343e7cae9
RDX: 0000000000000008 RSI: 0000000020000080 RDI: 0000000000000003
RBP: 00007fd343ec847a R08: 0000000020001100 R09: 000000000000001c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fd343f9bf80 R15: 00007ffd189ab868
 </TASK>

The buggy address belongs to the physical page:
page:ffffea0000b67200 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2d9c8
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000000 ffffea0001818708 ffffea0000b67308 0000000000000000
raw: 0000000000000000 0000000000150000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 29566, tgid 29559 (syz-executor.5), ts 1599073184948, free_ts 1614646216072
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x2d2/0x350 mm/page_alloc.c:1570
 prep_new_page mm/page_alloc.c:1577 [inline]
 get_page_from_freelist+0x10a9/0x31e0 mm/page_alloc.c:3221
 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4477
 alloc_pages+0x1a9/0x270 mm/mempolicy.c:2298
 alloc_slab_page mm/slub.c:1862 [inline]
 allocate_slab+0x24e/0x380 mm/slub.c:2009
 new_slab mm/slub.c:2062 [inline]
 ___slab_alloc+0x8bc/0x1570 mm/slub.c:3215
 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3314
 __slab_alloc_node mm/slub.c:3367 [inline]
 slab_alloc_node mm/slub.c:3460 [inline]
 kmem_cache_alloc_node+0x137/0x3f0 mm/slub.c:3515
 kmalloc_reserve+0x167/0x270 net/core/skbuff.c:559
 __alloc_skb+0x12b/0x330 net/core/skbuff.c:644
 alloc_skb include/linux/skbuff.h:1286 [inline]
 __ip_append_data+0x2e81/0x3da0 net/ipv4/ip_output.c:1126
 ip_append_data net/ipv4/ip_output.c:1361 [inline]
 ip_append_data+0x10f/0x190 net/ipv4/ip_output.c:1340
 raw_sendmsg+0xd28/0x3700 net/ipv4/raw.c:639
 inet_sendmsg+0x9d/0xe0 net/ipv4/af_inet.c:840
 sock_sendmsg_nosec net/socket.c:728 [inline]
 sock_sendmsg+0xd9/0x180 net/socket.c:751
 ____sys_sendmsg+0x2ac/0x940 net/socket.c:2538
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1161 [inline]
 free_unref_page_prepare+0x508/0xb90 mm/page_alloc.c:2348
 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2443
 __unfreeze_partials+0x21d/0x240 mm/slub.c:2647
 qlink_free mm/kasan/quarantine.c:166 [inline]
 qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:185
 kasan_quarantine_reduce+0x18b/0x1d0 mm/kasan/quarantine.c:292
 ____kasan_kmalloc mm/kasan/common.c:340 [inline]
 __kasan_kmalloc+0x86/0xb0 mm/kasan/common.c:383
 kasan_kmalloc include/linux/kasan.h:196 [inline]
 __do_kmalloc_node mm/slab_common.c:985 [inline]
 __kmalloc_node_track_caller+0x5e/0x100 mm/slab_common.c:1005
 kmalloc_reserve+0xef/0x270 net/core/skbuff.c:575
 __alloc_skb+0x12b/0x330 net/core/skbuff.c:644
 alloc_skb include/linux/skbuff.h:1286 [inline]
 alloc_skb_with_frags+0xe4/0x710 net/core/skbuff.c:6299
 sock_alloc_send_pskb+0x7c8/0x950 net/core/sock.c:2794
 sock_alloc_send_skb include/net/sock.h:1879 [inline]
 mld_newpack.isra.0+0x1ee/0x790 net/ipv6/mcast.c:1746
 add_grhead+0x295/0x340 net/ipv6/mcast.c:1849
 add_grec+0x10bb/0x1680 net/ipv6/mcast.c:1987
 mld_send_initial_cr.part.0+0xe2/0x260 net/ipv6/mcast.c:2234
 mld_send_initial_cr net/ipv6/mcast.c:2225 [inline]
 mld_dad_work+0x57/0x2e0 net/ipv6/mcast.c:2260

Memory state around the buggy address:
 ffff88802d9c8d80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88802d9c8e00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88802d9c8e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                          ^
 ffff88802d9c8f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88802d9c8f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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