================================================================== BUG: KASAN: slab-use-after-free in __xfrm_state_insert+0x8af/0x1450 net/xfrm/xfrm_state.c:1743 Read of size 1 at addr ffff88807de72db0 by task syz.4.2168/14234 CPU: 1 UID: 0 PID: 14234 Comm: syz.4.2168 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 __xfrm_state_insert+0x8af/0x1450 net/xfrm/xfrm_state.c:1743 xfrm_state_insert+0x54/0x60 net/xfrm/xfrm_state.c:1795 ipcomp6_tunnel_attach net/ipv6/ipcomp6.c:131 [inline] ipcomp6_init_state+0x655/0x900 net/ipv6/ipcomp6.c:163 __xfrm_init_state+0xa76/0x13f0 net/xfrm/xfrm_state.c:3188 xfrm_state_construct net/xfrm/xfrm_user.c:954 [inline] xfrm_add_sa+0x2f5b/0x4070 net/xfrm/xfrm_user.c:1019 xfrm_user_rcv_msg+0x7a3/0xab0 net/xfrm/xfrm_user.c:3501 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552 xfrm_netlink_rcv+0x79/0x90 net/xfrm/xfrm_user.c:3523 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82c/0x9e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:729 ____sys_sendmsg+0x505/0x830 net/socket.c:2614 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668 __sys_sendmsg net/socket.c:2700 [inline] __do_sys_sendmsg net/socket.c:2705 [inline] __se_sys_sendmsg net/socket.c:2703 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc08d38eec9 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:00007fc08b5d5038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fc08d5e6180 RCX: 00007fc08d38eec9 RDX: 0000000000000000 RSI: 00002000000035c0 RDI: 000000000000000b RBP: 00007fc08d411f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc08d5e6218 R14: 00007fc08d5e6180 R15: 00007ffe1aa8c398 Allocated by task 12033: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:330 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:356 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4191 [inline] slab_alloc_node mm/slub.c:4240 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4247 xfrm_state_alloc+0x24/0x2f0 net/xfrm/xfrm_state.c:733 pfkey_msg2xfrm_state net/key/af_key.c:1122 [inline] pfkey_add+0x6e4/0x2e00 net/key/af_key.c:1504 pfkey_process net/key/af_key.c:2848 [inline] pfkey_sendmsg+0xbfe/0x1090 net/key/af_key.c:3699 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:729 ____sys_sendmsg+0x505/0x830 net/socket.c:2614 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668 __sys_sendmsg net/socket.c:2700 [inline] __do_sys_sendmsg net/socket.c:2705 [inline] __se_sys_sendmsg net/socket.c:2703 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 10901: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2422 [inline] slab_free mm/slub.c:4695 [inline] kmem_cache_free+0x18f/0x400 mm/slub.c:4797 xfrm_state_free net/xfrm/xfrm_state.c:591 [inline] xfrm_state_gc_destroy net/xfrm/xfrm_state.c:618 [inline] xfrm_state_gc_task+0x52d/0x6b0 net/xfrm/xfrm_state.c:634 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff88807de72a80 which belongs to the cache xfrm_state of size 928 The buggy address is located 816 bytes inside of freed 928-byte region [ffff88807de72a80, ffff88807de72e20) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88807de70cc0 pfn:0x7de70 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801a5b98c0 0000000000000000 0000000000000001 raw: ffff88807de70cc0 00000000000f0003 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801a5b98c0 0000000000000000 0000000000000001 head: ffff88807de70cc0 00000000000f0003 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea0001f79c01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 6121, tgid 6120 (syz.0.38), ts 105135228311, free_ts 105132252210 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2492 [inline] allocate_slab+0x8a/0x370 mm/slub.c:2660 new_slab mm/slub.c:2714 [inline] ___slab_alloc+0xbeb/0x1420 mm/slub.c:3901 __slab_alloc mm/slub.c:3992 [inline] __slab_alloc_node mm/slub.c:4067 [inline] slab_alloc_node mm/slub.c:4228 [inline] kmem_cache_alloc_noprof+0x283/0x3c0 mm/slub.c:4247 xfrm_state_alloc+0x24/0x2f0 net/xfrm/xfrm_state.c:733 xfrm_state_construct net/xfrm/xfrm_user.c:889 [inline] xfrm_add_sa+0x17d1/0x4070 net/xfrm/xfrm_user.c:1019 xfrm_user_rcv_msg+0x7a3/0xab0 net/xfrm/xfrm_user.c:3501 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552 xfrm_netlink_rcv+0x79/0x90 net/xfrm/xfrm_user.c:3523 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82c/0x9e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:729 ____sys_sendmsg+0x505/0x830 net/socket.c:2614 page last free pid 6120 tgid 6120 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895 __slab_free+0x303/0x3c0 mm/slub.c:4606 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:340 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4191 [inline] slab_alloc_node mm/slub.c:4240 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4247 ptlock_alloc mm/memory.c:7161 [inline] ptlock_init include/linux/mm.h:2953 [inline] pmd_ptlock_init include/linux/mm.h:3081 [inline] pagetable_pmd_ctor include/linux/mm.h:3109 [inline] pmd_alloc_one_noprof include/asm-generic/pgalloc.h:145 [inline] __pmd_alloc+0xc6/0x3b0 mm/memory.c:6450 pmd_alloc include/linux/mm.h:2844 [inline] __handle_mm_fault+0x9ad/0x5440 mm/memory.c:6155 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6364 do_user_addr_fault+0xa81/0x1390 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 Memory state around the buggy address: ffff88807de72c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807de72d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807de72d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807de72e00: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc ffff88807de72e80: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ==================================================================