================================================================== BUG: KASAN: slab-use-after-free in __xfrm_state_insert+0xa6b/0x1700 net/xfrm/xfrm_state.c:1512 Read of size 1 at addr ffff88805e1e46f8 by task syz.1.479/7636 CPU: 0 PID: 7636 Comm: syz.1.479 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: 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_insert+0xa6b/0x1700 net/xfrm/xfrm_state.c:1512 xfrm_state_insert+0x54/0x60 net/xfrm/xfrm_state.c:1561 ipcomp6_tunnel_attach net/ipv6/ipcomp6.c:129 [inline] ipcomp6_init_state+0x5ab/0x7f0 net/ipv6/ipcomp6.c:161 __xfrm_init_state+0xd8b/0x11c0 net/xfrm/xfrm_state.c:2904 xfrm_state_construct net/xfrm/xfrm_user.c:741 [inline] xfrm_add_sa+0x236d/0x30a0 net/xfrm/xfrm_user.c:799 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 RIP: 0033:0x7f9949b8eec9 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:00007f994a99a038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f9949de6180 RCX: 00007f9949b8eec9 RDX: 0000000020000000 RSI: 00002000000035c0 RDI: 000000000000000a RBP: 00007f9949c11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9949de6218 R14: 00007f9949de6180 R15: 00007ffc3719c438 Allocated by task 7103: 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:3495 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3519 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 ffff88805e1e4400 which belongs to the cache xfrm_state of size 848 The buggy address is located 760 bytes inside of freed 848-byte region [ffff88805e1e4400, ffff88805e1e4750) The buggy address belongs to the physical page: page:ffffea0001787900 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88805e1e4000 pfn:0x5e1e4 head:ffffea0001787900 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 ffff888140683640 dead000000000122 0000000000000000 raw: ffff88805e1e4000 000000008010000e 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 5887, tgid 5881 (syz.3.5), ts 84194485494, free_ts 24969835917 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:1881 allocate_slab mm/slub.c:2028 [inline] new_slab+0x87/0x2e0 mm/slub.c:2081 ___slab_alloc+0xc6d/0x1300 mm/slub.c:3253 __slab_alloc mm/slub.c:3339 [inline] __slab_alloc_node mm/slub.c:3392 [inline] slab_alloc_node mm/slub.c:3485 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc+0x1b7/0x2e0 mm/slub.c:3519 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 free_contig_range+0xa1/0x160 mm/page_alloc.c:6369 destroy_args+0x80/0x850 mm/debug_vm_pgtable.c:1015 debug_vm_pgtable+0x3cc/0x410 mm/debug_vm_pgtable.c:1400 do_one_initcall+0x1fd/0x750 init/main.c:1238 do_initcall_level+0x137/0x1f0 init/main.c:1300 do_initcalls+0x69/0xd0 init/main.c:1316 kernel_init_freeable+0x3d2/0x570 init/main.c:1553 kernel_init+0x1d/0x1c0 init/main.c:1443 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Memory state around the buggy address: ffff88805e1e4580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805e1e4600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805e1e4680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805e1e4700: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc ffff88805e1e4780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================