================================================================== BUG: KASAN: slab-use-after-free in __hlist_del include/linux/list.h:982 [inline] BUG: KASAN: slab-use-after-free in hlist_del_rcu include/linux/rculist.h:560 [inline] BUG: KASAN: slab-use-after-free in __xfrm_state_delete+0x696/0xca0 net/xfrm/xfrm_state.c:830 Write of size 8 at addr ffff8880217ab330 by task syz.4.571/7760 CPU: 1 UID: 0 PID: 7760 Comm: syz.4.571 Not tainted 6.17.0-rc1-syzkaller-ge4414b01c1cd #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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 __hlist_del include/linux/list.h:982 [inline] hlist_del_rcu include/linux/rculist.h:560 [inline] __xfrm_state_delete+0x696/0xca0 net/xfrm/xfrm_state.c:830 xfrm_timer_handler+0x18f/0xa00 net/xfrm/xfrm_state.c:716 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1825 hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1842 handle_softirqs+0x283/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lockdep_unregister_key+0x2c5/0x310 kernel/locking/lockdep.c:6616 Code: 65 48 8b 05 bd bf 02 11 48 3b 44 24 10 0f 84 26 fe ff ff e8 7d b6 db 09 e8 a8 b7 db 09 41 f7 c7 00 02 00 00 74 bd fb 40 84 ed <75> bc eb cd 90 0f 0b 90 e9 19 ff ff ff 90 0f 0b 90 e9 2a ff ff ff RSP: 0018:ffffc9001d3ff998 EFLAGS: 00000246 RAX: 6c9e5dcf18679100 RBX: ffff88806c2fd298 RCX: 6c9e5dcf18679100 RDX: ffffffff93640338 RSI: ffffffff8d9ca8fc RDI: ffffffff8be33380 RBP: ffff88806c2fd200 R08: 0000000000000000 R09: ffffffff81aa82d8 R10: dffffc0000000000 R11: fffffbfff1f46fc7 R12: 0000000000000000 R13: 0000000000001000 R14: 0000000000000001 R15: 0000000000000203 __qdisc_destroy+0x166/0x420 net/sched/sch_generic.c:1083 netdev_for_each_tx_queue include/linux/netdevice.h:2657 [inline] dev_shutdown+0x93/0x440 net/sched/sch_generic.c:1494 unregister_netdevice_many_notify+0xe0f/0x1ff0 net/core/dev.c:12136 unregister_netdevice_many net/core/dev.c:12211 [inline] unregister_netdevice_queue+0x33c/0x380 net/core/dev.c:12055 unregister_netdevice include/linux/netdevice.h:3382 [inline] __tun_detach+0xda4/0x1560 drivers/net/tun.c:621 tun_detach drivers/net/tun.c:637 [inline] tun_chr_close+0x10a/0x1c0 drivers/net/tun.c:3433 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f655918ebe9 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:00007ffe9dabf2b8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f65593b7da0 RCX: 00007f655918ebe9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f65593b7da0 R08: 00000000000183d8 R09: 0000001e9dabf5af R10: 00000000005e727c R11: 0000000000000246 R12: 0000000000030fbb R13: 00007ffe9dabf3b0 R14: ffffffffffffffff R15: 00007ffe9dabf3d0 Allocated by task 6951: 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:4180 [inline] slab_alloc_node mm/slub.c:4229 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4236 xfrm_state_alloc+0x24/0x2f0 net/xfrm/xfrm_state.c:733 __find_acq_core+0x8a7/0x1c00 net/xfrm/xfrm_state.c:1833 xfrm_find_acq+0x78/0xa0 net/xfrm/xfrm_state.c:2353 xfrm_alloc_userspi+0x6b3/0xc90 net/xfrm/xfrm_user.c:1863 xfrm_user_rcv_msg+0x7a0/0xab0 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+0x21c/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 941: 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:2417 [inline] slab_free mm/slub.c:4680 [inline] kmem_cache_free+0x18f/0x400 mm/slub.c:4782 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+0xade/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 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 ffff8880217ab300 which belongs to the cache xfrm_state of size 928 The buggy address is located 48 bytes inside of freed 928-byte region [ffff8880217ab300, ffff8880217ab6a0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880217a9dc0 pfn:0x217a8 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 ffff88801ab058c0 0000000000000000 0000000000000001 raw: ffff8880217a9dc0 00000000000f0007 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801ab058c0 0000000000000000 0000000000000001 head: ffff8880217a9dc0 00000000000f0007 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea000085ea01 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 6153, tgid 6149 (syz.3.47), ts 112378303821, free_ts 112315241070 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:2487 [inline] allocate_slab+0x8a/0x370 mm/slub.c:2655 new_slab mm/slub.c:2709 [inline] ___slab_alloc+0xbeb/0x1410 mm/slub.c:3891 __slab_alloc mm/slub.c:3981 [inline] __slab_alloc_node mm/slub.c:4056 [inline] slab_alloc_node mm/slub.c:4217 [inline] kmem_cache_alloc_noprof+0x283/0x3c0 mm/slub.c:4236 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+0xbfb/0x1090 net/key/af_key.c:3699 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x21c/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 page last free pid 6127 tgid 6127 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 free_large_kmalloc+0x13a/0x1f0 mm/slub.c:4805 device_release+0x99/0x1c0 drivers/base/core.c:-1 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x22b/0x480 lib/kobject.c:737 netdev_run_todo+0xd2e/0xea0 net/core/dev.c:11496 tun_detach drivers/net/tun.c:640 [inline] tun_chr_close+0x13c/0x1c0 drivers/net/tun.c:3433 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff8880217ab200: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8880217ab280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880217ab300: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880217ab380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880217ab400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 65 48 8b 05 bd bf 02 mov %gs:0x1102bfbd(%rip),%rax # 0x1102bfc5 7: 11 8: 48 3b 44 24 10 cmp 0x10(%rsp),%rax d: 0f 84 26 fe ff ff je 0xfffffe39 13: e8 7d b6 db 09 call 0x9dbb695 18: e8 a8 b7 db 09 call 0x9dbb7c5 1d: 41 f7 c7 00 02 00 00 test $0x200,%r15d 24: 74 bd je 0xffffffe3 26: fb sti 27: 40 84 ed test %bpl,%bpl * 2a: 75 bc jne 0xffffffe8 <-- trapping instruction 2c: eb cd jmp 0xfffffffb 2e: 90 nop 2f: 0f 0b ud2 31: 90 nop 32: e9 19 ff ff ff jmp 0xffffff50 37: 90 nop 38: 0f 0b ud2 3a: 90 nop 3b: e9 2a ff ff ff jmp 0xffffff6a