================================================================== BUG: KFENCE: use-after-free write in __hlist_del include/linux/list.h:982 [inline] BUG: KFENCE: use-after-free write in hlist_del_rcu include/linux/rculist.h:560 [inline] BUG: KFENCE: use-after-free write in __xfrm_state_delete+0x696/0xca0 net/xfrm/xfrm_state.c:830 Use-after-free write at 0xffff88823bfe8030 (in kfence-#243): __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+0x57/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 kfence-#243: 0xffff88823bfe8fe0-0xffff88823bfe8ff7, size=24, cache=kmalloc-32 allocated by task 14585 on cpu 0 at 378.032640s (7.815203s ago): kmalloc_noprof include/linux/slab.h:905 [inline] slab_free_hook mm/slub.c:2369 [inline] slab_free mm/slub.c:4680 [inline] kmem_cache_free+0x166/0x400 mm/slub.c:4782 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 freed by task 5867 on cpu 0 at 378.062508s (7.820752s ago): slab_free_after_rcu_debug+0x60/0x2a0 mm/slub.c:4717 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0xca8/0x1770 kernel/rcu/tree.c:2861 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 lock_release+0x2b5/0x3e0 kernel/locking/lockdep.c:5893 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 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 anon_vma_chain_alloc mm/rmap.c:142 [inline] anon_vma_fork+0x1f1/0x500 mm/rmap.c:364 dup_mmap+0x9eb/0x1ac0 mm/mmap.c:1797 dup_mm kernel/fork.c:1485 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1537 copy_process+0x1706/0x3c00 kernel/fork.c:2175 kernel_clone+0x21e/0x840 kernel/fork.c:2605 __do_sys_clone kernel/fork.c:2748 [inline] __se_sys_clone kernel/fork.c:2732 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2732 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 CPU: 1 UID: 0 PID: 14839 Comm: syz.3.2768 Not tainted 6.16.0-syzkaller-12071-gf8262b8dadfa #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:__hlist_del include/linux/list.h:982 [inline] RIP: 0010:hlist_del_rcu include/linux/rculist.h:560 [inline] RIP: 0010:__xfrm_state_delete+0x696/0xca0 net/xfrm/xfrm_state.c:830 Code: 74 34 e8 dd 3c a0 f7 48 83 c3 08 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 4a a8 03 f8 <4c> 89 3b eb 0c e8 b0 3c a0 f7 eb 34 e8 a9 3c a0 f7 48 b8 00 00 00 RSP: 0000:ffffc900052479f0 EFLAGS: 00010246 RAX: 1ffff110477fd006 RBX: ffff88823bfe8030 RCX: dffffc0000000000 RDX: 0000000000000100 RSI: 0000000004000000 RDI: ffff88805763aaa8 RBP: 1ffff1100aec7556 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000a48f2c R12: ffff88805763aab0 R13: ffff888030d9c880 R14: ffff88805763aa80 R15: ffff8880277d8018 FS: 000055557def2500(0000) GS:ffff888125d21000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff88823bfe8030 CR3: 00000000787de000 CR4: 00000000003526f0 Call Trace: 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+0x57/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0033:0x7fbbea44d9e7 Code: 1f 40 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 41 89 fb 44 8d 56 04 4c 8d 0d 22 46 35 00 89 f0 4c 8d 05 19 26 35 00 <89> c2 81 e2 ff 1f 00 00 49 8b 0c d1 48 39 f1 74 28 48 85 c9 74 29 RSP: 002b:00007ffe528c88f8 EFLAGS: 00000246 RAX: 000000008223ac95 RBX: 00007fbbeb2e5720 RCX: 0000000000076beb RDX: ffffffff8223a083 RSI: ffffffff8223ac95 RDI: 0000000000000016 RBP: ffffffff8223ac95 R08: 00007fbbea7a0000 R09: 00007fbbea7a2000 R10: 000000008223ac99 R11: 0000000000000016 R12: 0000000000000016 R13: 0000000000000000 R14: ffffffff8223a083 R15: 0000000000076beb ================================================================== ---------------- Code disassembly (best guess): 0: 74 34 je 0x36 2: e8 dd 3c a0 f7 call 0xf7a03ce4 7: 48 83 c3 08 add $0x8,%rbx b: 48 89 d8 mov %rbx,%rax e: 48 c1 e8 03 shr $0x3,%rax 12: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx 19: fc ff df 1c: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) 20: 74 08 je 0x2a 22: 48 89 df mov %rbx,%rdi 25: e8 4a a8 03 f8 call 0xf803a874 * 2a: 4c 89 3b mov %r15,(%rbx) <-- trapping instruction 2d: eb 0c jmp 0x3b 2f: e8 b0 3c a0 f7 call 0xf7a03ce4 34: eb 34 jmp 0x6a 36: e8 a9 3c a0 f7 call 0xf7a03ce4 3b: 48 rex.W 3c: b8 .byte 0xb8 3d: 00 00 add %al,(%rax)