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BUG: KASAN: slab-out-of-bounds in xfrm_policy_inexact_list_reinsert+0x5df/0x690 net/xfrm/xfrm_policy.c:874
Read of size 1 at addr ffff888073b6a600 by task syz.0.174/4934

CPU: 0 PID: 4934 Comm: syz.0.174 Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 xfrm_policy_inexact_list_reinsert+0x5df/0x690 net/xfrm/xfrm_policy.c:874
 xfrm_policy_inexact_node_merge net/xfrm/xfrm_policy.c:1006 [inline]
 xfrm_policy_inexact_insert_node+0x950/0xb60 net/xfrm/xfrm_policy.c:1062
 xfrm_policy_inexact_alloc_chain+0x7cf/0xea0 net/xfrm/xfrm_policy.c:1178
 xfrm_policy_inexact_insert+0xe0/0x1460 net/xfrm/xfrm_policy.c:1221
 xfrm_policy_insert+0x112/0x930 net/xfrm/xfrm_policy.c:1605
 xfrm_add_policy+0x4d6/0x860 net/xfrm/xfrm_user.c:1833
 xfrm_user_rcv_msg+0x58d/0x860 net/xfrm/xfrm_user.c:2979
 netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2489
 xfrm_netlink_rcv+0x75/0x90 net/xfrm/xfrm_user.c:3001
 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline]
 netlink_unicast+0x77c/0x920 net/netlink/af_netlink.c:1337
 netlink_sendmsg+0x8ab/0xbc0 net/netlink/af_netlink.c:1905
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2436
 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2490
 __sys_sendmsg net/socket.c:2519 [inline]
 __do_sys_sendmsg net/socket.c:2528 [inline]
 __se_sys_sendmsg+0x190/0x250 net/socket.c:2526
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7ff06d50d929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff06b375038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ff06d734fa0 RCX: 00007ff06d50d929
RDX: 0000000000000000 RSI: 0000200000000580 RDI: 0000000000000006
RBP: 00007ff06d58fb39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff06d734fa0 R15: 00007ffc370b2a18
 </TASK>

Allocated by task 4934:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc mm/kasan/common.c:513 [inline]
 __kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522
 kmalloc include/linux/slab.h:609 [inline]
 sk_prot_alloc+0xe7/0x210 net/core/sock.c:1864
 sk_alloc+0x2f/0x310 net/core/sock.c:1917
 pfkey_create+0xd8/0x560 net/key/af_key.c:152
 __sock_create+0x47b/0x900 net/socket.c:1486
 sock_create net/socket.c:1542 [inline]
 __sys_socket+0xe2/0x170 net/socket.c:1584
 __do_sys_socket net/socket.c:1593 [inline]
 __se_sys_socket net/socket.c:1591 [inline]
 __x64_sys_socket+0x76/0x80 net/socket.c:1591
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff888073b6a000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1536 bytes inside of
 2048-byte region [ffff888073b6a000, ffff888073b6a800)
The buggy address belongs to the page:
page:ffffea0001ceda00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x73b68
head:ffffea0001ceda00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea000185ce00 0000000200000002 ffff888016842000
raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4170, ts 70218356788, free_ts 68618627622
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192
 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5474
 alloc_slab_page mm/slub.c:1775 [inline]
 allocate_slab mm/slub.c:1912 [inline]
 new_slab+0xc0/0x4b0 mm/slub.c:1975
 ___slab_alloc+0x81e/0xdf0 mm/slub.c:3008
 __slab_alloc mm/slub.c:3095 [inline]
 slab_alloc_node mm/slub.c:3186 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 __kmalloc_track_caller+0x1cb/0x330 mm/slub.c:4925
 kmemdup+0x22/0x50 mm/util.c:128
 neigh_sysctl_register+0x9b/0xa80 net/core/neighbour.c:3652
 addrconf_sysctl_register+0xac/0x1b0 net/ipv6/addrconf.c:7150
 ipv6_add_dev+0xbf3/0x1190 net/ipv6/addrconf.c:454
 addrconf_notify+0x66f/0xf00 net/ipv6/addrconf.c:3582
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391
 call_netdevice_notifiers_extack net/core/dev.c:2061 [inline]
 call_netdevice_notifiers net/core/dev.c:2075 [inline]
 register_netdevice+0x1275/0x16b0 net/core/dev.c:10428
 veth_newlink+0x668/0xda0 drivers/net/veth.c:1683
 __rtnl_newlink net/core/rtnetlink.c:3524 [inline]
 rtnl_newlink+0x114c/0x17d0 net/core/rtnetlink.c:3572
 rtnetlink_rcv_msg+0x9b9/0xe60 net/core/rtnetlink.c:5650
 netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2489
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page+0x94/0x280 mm/page_alloc.c:3396
 put_page include/linux/mm.h:1247 [inline]
 __skb_frag_unref include/linux/skbuff.h:3231 [inline]
 skb_release_data+0x3fa/0x850 net/core/skbuff.c:672
 skb_release_all net/core/skbuff.c:742 [inline]
 __kfree_skb+0x4c/0x60 net/core/skbuff.c:756
 sk_eat_skb include/net/sock.h:2742 [inline]
 tcp_recvmsg_locked+0x14d5/0x2760 net/ipv4/tcp.c:2517
 tcp_recvmsg+0x350/0x710 net/ipv4/tcp.c:2563
 inet_recvmsg+0x136/0x1e0 net/ipv4/af_inet.c:868
 sock_recvmsg_nosec net/socket.c:966 [inline]
 sock_recvmsg net/socket.c:984 [inline]
 sock_read_iter+0x2a2/0x340 net/socket.c:1057
 call_read_iter include/linux/fs.h:2166 [inline]
 new_sync_read fs/read_write.c:404 [inline]
 vfs_read+0x725/0xcf0 fs/read_write.c:485
 ksys_read+0x14d/0x250 fs/read_write.c:623
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Memory state around the buggy address:
 ffff888073b6a500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888073b6a580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc
>ffff888073b6a600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff888073b6a680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888073b6a700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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