================================================================== 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+0x9e5/0xa30 net/xfrm/xfrm_state.c:830 Write of size 8 at addr ffff88805a9188b0 by task swapper/0/0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 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+0x9e5/0xa30 net/xfrm/xfrm_state.c:830 xfrm_timer_handler+0x86c/0xf10 net/xfrm/xfrm_state.c:716 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x1ff/0xad0 kernel/time/hrtimer.c:1825 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1842 handle_softirqs+0x219/0x8e0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0x109/0x170 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+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:sched_core_balance+0xa0/0xeb0 kernel/sched/core.c:6382 Code: 12 5c 8e e8 62 3a 0d 00 e8 9d b2 09 0a 41 5b 85 c0 0f 85 31 0a 00 00 4c 89 e7 e8 7b 72 fe ff e8 96 e6 38 00 fb 48 63 44 24 50 <48> c7 c3 00 53 d8 93 48 89 44 24 08 48 83 f8 07 0f 87 9c 0c 00 00 RSP: 0018:ffffffff8e207b10 EFLAGS: 00000206 RAX: 0000000000000000 RBX: ffff8880b8423f10 RCX: ffffffff81c3746f RDX: 0000000000000000 RSI: ffffffff8de522e0 RDI: ffffffff8c162d80 RBP: ffffffff8e207c30 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90ab6b97 R11: 0000000000000000 R12: ffff8880b843a300 R13: ffff88801f774880 R14: 0000000000000000 R15: dffffc0000000000 do_balance_callbacks kernel/sched/core.c:5011 [inline] __balance_callbacks kernel/sched/core.c:5065 [inline] finish_lock_switch kernel/sched/core.c:5104 [inline] finish_task_switch.isra.0+0x46f/0xc10 kernel/sched/core.c:5223 context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1198/0x5de0 kernel/sched/core.c:6961 schedule_idle+0x5c/0x90 kernel/sched/core.c:7084 do_idle+0x2b6/0x510 kernel/sched/idle.c:358 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 rest_init+0x16b/0x2b0 init/main.c:744 start_kernel+0x3ee/0x4d0 init/main.c:1097 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x148 Allocated by task 10333: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:330 [inline] __kasan_slab_alloc+0x89/0x90 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+0x1cb/0x3b0 mm/slub.c:4247 xfrm_state_alloc+0x23/0x5c0 net/xfrm/xfrm_state.c:733 __find_acq_core+0xb59/0x2900 net/xfrm/xfrm_state.c:1833 xfrm_find_acq+0x7b/0xa0 net/xfrm/xfrm_state.c:2353 xfrm_alloc_userspi+0x58e/0xbb0 net/xfrm/xfrm_user.c:1863 xfrm_user_rcv_msg+0x58e/0xc00 net/xfrm/xfrm_user.c:3501 netlink_rcv_skb+0x155/0x420 net/netlink/af_netlink.c:2552 xfrm_netlink_rcv+0x71/0x90 net/xfrm/xfrm_user.c:3523 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg net/socket.c:729 [inline] ____sys_sendmsg+0xa98/0xc70 net/socket.c:2614 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668 __sys_sendmsg+0x16d/0x220 net/socket.c:2700 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5982: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x60/0x70 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+0x2d1/0x4d0 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+0x50a/0x770 net/xfrm/xfrm_state.c:634 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x5d4/0x6f0 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 ffff88805a918880 which belongs to the cache xfrm_state of size 928 The buggy address is located 48 bytes inside of freed 928-byte region [ffff88805a918880, ffff88805a918c20) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5a918 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff8881452e6140 dead000000000122 0000000000000000 raw: 0000000000000000 00000000800f000f 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff8881452e6140 dead000000000122 0000000000000000 head: 0000000000000000 00000000800f000f 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea00016a4601 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 7443, tgid 7440 (syz.3.375), ts 207982577898, free_ts 201180519511 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:5148 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2492 [inline] allocate_slab mm/slub.c:2660 [inline] new_slab+0x247/0x330 mm/slub.c:2714 ___slab_alloc+0xcf2/0x1750 mm/slub.c:3901 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3992 __slab_alloc_node mm/slub.c:4067 [inline] slab_alloc_node mm/slub.c:4228 [inline] kmem_cache_alloc_noprof+0xef/0x3b0 mm/slub.c:4247 xfrm_state_alloc+0x23/0x5c0 net/xfrm/xfrm_state.c:733 xfrm_state_construct net/xfrm/xfrm_user.c:889 [inline] xfrm_add_sa+0x1283/0x5c50 net/xfrm/xfrm_user.c:1019 xfrm_user_rcv_msg+0x58e/0xc00 net/xfrm/xfrm_user.c:3501 netlink_rcv_skb+0x155/0x420 net/netlink/af_netlink.c:2552 xfrm_netlink_rcv+0x71/0x90 net/xfrm/xfrm_user.c:3523 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg net/socket.c:729 [inline] ____sys_sendmsg+0xa98/0xc70 net/socket.c:2614 page last free pid 7367 tgid 7367 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] free_unref_folios+0xa61/0x16b0 mm/page_alloc.c:2952 folios_put_refs+0x56f/0x740 mm/swap.c:997 folio_batch_release include/linux/pagevec.h:101 [inline] truncate_inode_pages_range+0x311/0xe50 mm/truncate.c:383 kill_bdev block/bdev.c:91 [inline] blkdev_flush_mapping+0xfb/0x290 block/bdev.c:712 blkdev_put_whole+0xc4/0xf0 block/bdev.c:719 bdev_release+0x47e/0x6d0 block/bdev.c:1144 blkdev_release+0x15/0x20 block/fops.c:699 __fput+0x402/0xb70 fs/file_table.c:468 task_work_run+0x150/0x240 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x86f/0x2bf0 kernel/exit.c:961 do_group_exit+0xd3/0x2a0 kernel/exit.c:1102 __do_sys_exit_group kernel/exit.c:1113 [inline] __se_sys_exit_group kernel/exit.c:1111 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1111 x64_sys_call+0x14fa/0x1720 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88805a918780: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff88805a918800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88805a918880: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805a918900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805a918980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 3 bytes skipped: 0: e8 62 3a 0d 00 call 0xd3a67 5: e8 9d b2 09 0a call 0xa09b2a7 a: 41 5b pop %r11 c: 85 c0 test %eax,%eax e: 0f 85 31 0a 00 00 jne 0xa45 14: 4c 89 e7 mov %r12,%rdi 17: e8 7b 72 fe ff call 0xfffe7297 1c: e8 96 e6 38 00 call 0x38e6b7 21: fb sti 22: 48 63 44 24 50 movslq 0x50(%rsp),%rax * 27: 48 c7 c3 00 53 d8 93 mov $0xffffffff93d85300,%rbx <-- trapping instruction 2e: 48 89 44 24 08 mov %rax,0x8(%rsp) 33: 48 83 f8 07 cmp $0x7,%rax 37: 0f 87 9c 0c 00 00 ja 0xcd9