==================================================================
BUG: KASAN: slab-use-after-free in __xfrm_state_lookup+0x6b2/0x8d0 net/xfrm/xfrm_state.c:1084
Read of size 2 at addr ffff88805cdbc122 by task syz.1.1329/10429

CPU: 1 PID: 10429 Comm: syz.1.1329 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <IRQ>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xac/0x220 mm/kasan/report.c:468
 kasan_report+0x117/0x150 mm/kasan/report.c:581
 __xfrm_state_lookup+0x6b2/0x8d0 net/xfrm/xfrm_state.c:1084
 xfrm_state_lookup+0xef/0x1a0 net/xfrm/xfrm_state.c:2042
 xfrm_input+0x3d62/0x6a20 net/xfrm/xfrm_input.c:575
 tunnel4_rcv+0xd7/0x2c0 net/ipv4/tunnel4.c:103
 ip_protocol_deliver_rcu+0x20e/0x3f0 net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0x2ca/0x510 net/ipv4/ip_input.c:233
 NF_HOOK+0x303/0x390 include/linux/netfilter.h:304
 NF_HOOK+0x303/0x390 include/linux/netfilter.h:304
 __netif_receive_skb_one_core net/core/dev.c:5608 [inline]
 __netif_receive_skb+0xcc/0x290 net/core/dev.c:5722
 process_backlog+0x380/0x6e0 net/core/dev.c:6050
 __napi_poll+0xc0/0x460 net/core/dev.c:6612
 napi_poll net/core/dev.c:6679 [inline]
 net_rx_action+0x5ea/0xbf0 net/core/dev.c:6815
 handle_softirqs+0x280/0x820 kernel/softirq.c:578
 do_softirq+0xed/0x180 kernel/softirq.c:479
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x178/0x1c0 kernel/softirq.c:406
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:856 [inline]
 __dev_queue_xmit+0x1449/0x35a0 net/core/dev.c:4452
 neigh_output include/net/neighbour.h:543 [inline]
 ip_finish_output2+0xd21/0x11d0 net/ipv4/ip_output.c:235
 dst_output include/net/dst.h:467 [inline]
 ip_local_out net/ipv4/ip_output.c:129 [inline]
 ip_send_skb+0x12f/0x1d0 net/ipv4/ip_output.c:1491
 udp_send_skb+0xa37/0x13a0 net/ipv4/udp.c:984
 udp_sendmsg+0x1ae0/0x2380 net/ipv4/udp.c:1270
 udpv6_sendmsg+0x9f5/0x22f0 net/ipv6/udp.c:1400
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x5bf/0x950 net/socket.c:2595
 ___sys_sendmsg+0x220/0x290 net/socket.c:2649
 __sys_sendmmsg+0x275/0x4a0 net/socket.c:2735
 __do_sys_sendmmsg net/socket.c:2764 [inline]
 __se_sys_sendmmsg net/socket.c:2761 [inline]
 __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2761
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f19be38ebe9
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:00007f19bf28f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f19be5c5fa0 RCX: 00007f19be38ebe9
RDX: 0400000000000172 RSI: 0000200000003cc0 RDI: 0000000000000005
RBP: 00007f19be411e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f19be5c6038 R14: 00007f19be5c5fa0 R15: 00007ffda21efd48
 </TASK>

Allocated by task 6191:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:328
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767
 slab_alloc_node mm/slub.c:3485 [inline]
 slab_alloc mm/slub.c:3493 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3500 [inline]
 kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3509
 kmem_cache_zalloc include/linux/slab.h:711 [inline]
 xfrm_state_alloc+0x22/0x2a0 net/xfrm/xfrm_state.c:661
 __find_acq_core+0x7d8/0x19d0 net/xfrm/xfrm_state.c:1598
 xfrm_find_acq+0x6a/0x90 net/xfrm/xfrm_state.c:2070
 xfrm_alloc_userspi+0x57a/0xa90 net/xfrm/xfrm_user.c:1613
 xfrm_user_rcv_msg+0x596/0x870 net/xfrm/xfrm_user.c:3169
 netlink_rcv_skb+0x216/0x480 net/netlink/af_netlink.c:2545
 xfrm_netlink_rcv+0x79/0x90 net/xfrm/xfrm_user.c:3191
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x5bf/0x950 net/socket.c:2595
 ___sys_sendmsg+0x220/0x290 net/socket.c:2649
 __sys_sendmsg net/socket.c:2678 [inline]
 __do_sys_sendmsg net/socket.c:2687 [inline]
 __se_sys_sendmsg+0x1a5/0x270 net/socket.c:2685
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff88805cdbc000
 which belongs to the cache xfrm_state of size 848
The buggy address is located 290 bytes inside of
 freed 848-byte region [ffff88805cdbc000, ffff88805cdbc350)

The buggy address belongs to the physical page:
page:ffffea0001736f00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5cdbc
head:ffffea0001736f00 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff88801c2dd280 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x152820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 6191, tgid 6188 (syz.1.105), ts 108117833441, free_ts 108015278462
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554
 prep_new_page mm/page_alloc.c:1561 [inline]
 get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191
 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
 alloc_slab_page+0x5d/0x170 mm/slub.c:1876
 allocate_slab mm/slub.c:2023 [inline]
 new_slab+0x87/0x2e0 mm/slub.c:2076
 ___slab_alloc+0xc6d/0x12f0 mm/slub.c:3230
 __slab_alloc mm/slub.c:3329 [inline]
 __slab_alloc_node mm/slub.c:3382 [inline]
 slab_alloc_node mm/slub.c:3475 [inline]
 slab_alloc mm/slub.c:3493 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3500 [inline]
 kmem_cache_alloc+0x1b7/0x2e0 mm/slub.c:3509
 kmem_cache_zalloc include/linux/slab.h:711 [inline]
 xfrm_state_alloc+0x22/0x2a0 net/xfrm/xfrm_state.c:661
 __find_acq_core+0x7d8/0x19d0 net/xfrm/xfrm_state.c:1598
 xfrm_find_acq+0x6a/0x90 net/xfrm/xfrm_state.c:2070
 xfrm_alloc_userspi+0x57a/0xa90 net/xfrm/xfrm_user.c:1613
 xfrm_user_rcv_msg+0x596/0x870 net/xfrm/xfrm_user.c:3169
 netlink_rcv_skb+0x216/0x480 net/netlink/af_netlink.c:2545
 xfrm_netlink_rcv+0x79/0x90 net/xfrm/xfrm_user.c:3191
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1894
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1154 [inline]
 free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336
 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429
 __slab_free+0x35e/0x410 mm/slub.c:3722
 qlink_free mm/kasan/quarantine.c:166 [inline]
 qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185
 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767
 slab_alloc_node mm/slub.c:3485 [inline]
 slab_alloc mm/slub.c:3493 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3500 [inline]
 kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3509
 vm_area_dup+0x27/0x270 kernel/fork.c:501
 dup_mmap kernel/fork.c:711 [inline]
 dup_mm kernel/fork.c:1692 [inline]
 copy_mm+0xc08/0x1c20 kernel/fork.c:1741
 copy_process+0x16d3/0x3d70 kernel/fork.c:2506
 kernel_clone+0x21b/0x840 kernel/fork.c:2914
 __do_sys_clone kernel/fork.c:3057 [inline]
 __se_sys_clone kernel/fork.c:3041 [inline]
 __x64_sys_clone+0x18c/0x1e0 kernel/fork.c:3041
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Memory state around the buggy address:
 ffff88805cdbc000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88805cdbc080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88805cdbc100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff88805cdbc180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88805cdbc200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================