================================================================== BUG: KASAN: use-after-free in hlist_add_head include/linux/list.h:930 [inline] BUG: KASAN: use-after-free in enqueue_timer+0xae/0x480 kernel/time/timer.c:611 Write of size 8 at addr ffff88810987ca00 by task syz.1.2066/7317 CPU: 1 PID: 7317 Comm: syz.1.2066 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106 print_address_description+0x71/0x1e0 mm/kasan/report.c:316 print_report+0x4a/0x60 mm/kasan/report.c:418 kasan_report+0x122/0x150 mm/kasan/report.c:522 __asan_report_store8_noabort+0x17/0x20 mm/kasan/report_generic.c:356 hlist_add_head include/linux/list.h:930 [inline] enqueue_timer+0xae/0x480 kernel/time/timer.c:611 __mod_timer+0x79f/0xb30 kernel/time/timer.c:-1 mod_timer+0x1f/0x30 kernel/time/timer.c:1172 neigh_timer_handler+0x937/0xf00 net/core/neighbour.c:1153 call_timer_fn+0x46/0x2a0 kernel/time/timer.c:1510 expire_timers kernel/time/timer.c:1555 [inline] __run_timers+0x639/0x9a0 kernel/time/timer.c:1826 run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1839 handle_softirqs+0x1d7/0x600 kernel/softirq.c:642 __do_softirq kernel/softirq.c:680 [inline] invoke_softirq kernel/softirq.c:497 [inline] __irq_exit_rcu+0x52/0xf0 kernel/softirq.c:729 irq_exit_rcu+0x9/0x10 kernel/softirq.c:741 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x58/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0033:0x7ff6ed24d9d0 Code: 41 5e c3 0f 1f 80 00 00 00 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 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 36 00 89 f0 4c 8d 05 19 26 36 RSP: 002b:00007ffe46f69e38 EFLAGS: 00000246 RAX: 000000000000088d RBX: 00007ff6ee0f5720 RCX: 0000000000006bed RDX: ffffffff83b77c23 RSI: ffffffff83b77b10 RDI: 00000000000000ff RBP: ffffffff83b77b10 R08: 00007ff6ed5c5f40 R09: 00007ff6ed5b2000 R10: 00007ff6ebdf9008 R11: 00000000000000ff R12: 00000000000000ff R13: 0000000000000000 R14: ffffffff83b77c23 R15: 0000000000006bed Allocated by task 7266: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_alloc_info+0x25/0x30 mm/kasan/generic.c:505 ____kasan_kmalloc mm/kasan/common.c:379 [inline] __kasan_kmalloc+0x95/0xb0 mm/kasan/common.c:388 kasan_kmalloc include/linux/kasan.h:212 [inline] __do_kmalloc_node mm/slab_common.c:938 [inline] __kmalloc+0xb1/0x1e0 mm/slab_common.c:951 kmalloc include/linux/slab.h:568 [inline] kzalloc include/linux/slab.h:699 [inline] hci_alloc_dev_priv+0x27/0x1bd0 net/bluetooth/hci_core.c:2433 hci_alloc_dev include/net/bluetooth/hci_core.h:1484 [inline] hci_uart_register_dev drivers/bluetooth/hci_ldisc.c:641 [inline] hci_uart_set_proto drivers/bluetooth/hci_ldisc.c:719 [inline] hci_uart_tty_ioctl+0x3d6/0xa20 drivers/bluetooth/hci_ldisc.c:774 tty_ioctl+0x8ef/0xc60 drivers/tty/tty_io.c:2785 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0x12f/0x1b0 fs/ioctl.c:856 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:856 x64_sys_call+0x58b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:17 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 7266: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x31/0x50 mm/kasan/generic.c:516 ____kasan_slab_free+0x132/0x180 mm/kasan/common.c:241 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:249 kasan_slab_free include/linux/kasan.h:178 [inline] slab_free_hook mm/slub.c:1745 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1771 slab_free mm/slub.c:3686 [inline] __kmem_cache_free+0xb7/0x1b0 mm/slub.c:3702 kfree+0x6f/0xf0 mm/slab_common.c:990 hci_release_dev+0x12a3/0x13b0 net/bluetooth/hci_core.c:2761 bt_host_release+0x82/0x90 net/bluetooth/hci_sysfs.c:85 device_release+0xa4/0x1d0 drivers/base/core.c:-1 kobject_cleanup lib/kobject.c:681 [inline] kobject_release lib/kobject.c:712 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x19d/0x280 lib/kobject.c:729 put_device+0x1f/0x30 drivers/base/core.c:3806 hci_dev_put include/net/bluetooth/hci_core.h:1444 [inline] hci_dev_cmd+0x265/0x720 net/bluetooth/hci_core.c:795 hci_sock_ioctl+0x41e/0x7f0 net/bluetooth/hci_sock.c:1096 sock_do_ioctl+0x101/0x310 net/socket.c:1194 sock_ioctl+0x4d8/0x6e0 net/socket.c:1311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0x12f/0x1b0 fs/ioctl.c:856 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:856 x64_sys_call+0x58b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:17 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb6/0xc0 mm/kasan/generic.c:486 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496 insert_work+0x51/0x300 kernel/workqueue.c:1368 __queue_work+0x9b1/0xd30 kernel/workqueue.c:1527 queue_work_on+0xd2/0x140 kernel/workqueue.c:1555 queue_work include/linux/workqueue.h:510 [inline] hci_cmd_sync_run net/bluetooth/hci_sync.c:140 [inline] __hci_cmd_sync_sk+0xa3e/0xcf0 net/bluetooth/hci_sync.c:162 __hci_cmd_sync_status_sk net/bluetooth/hci_sync.c:253 [inline] __hci_cmd_sync_status net/bluetooth/hci_sync.c:277 [inline] hci_cmd_sync_status+0x53/0x120 net/bluetooth/hci_sync.c:288 hci_dev_cmd+0x33b/0x720 net/bluetooth/hci_core.c:749 hci_sock_ioctl+0x41e/0x7f0 net/bluetooth/hci_sock.c:1096 sock_do_ioctl+0x101/0x310 net/socket.c:1194 sock_ioctl+0x4d8/0x6e0 net/socket.c:1311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0x12f/0x1b0 fs/ioctl.c:856 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:856 x64_sys_call+0x58b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:17 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Second to last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb6/0xc0 mm/kasan/generic.c:486 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496 insert_work+0x51/0x300 kernel/workqueue.c:1368 __queue_work+0x9b1/0xd30 kernel/workqueue.c:1527 queue_work_on+0xd2/0x140 kernel/workqueue.c:1555 queue_work include/linux/workqueue.h:510 [inline] hci_cmd_timeout+0x191/0x200 net/bluetooth/hci_core.c:1468 process_one_work+0x71f/0xc40 kernel/workqueue.c:2302 worker_thread+0xa29/0x11f0 kernel/workqueue.c:2449 kthread+0x281/0x320 kernel/kthread.c:386 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 The buggy address belongs to the object at ffff88810987c000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 2560 bytes inside of 8192-byte region [ffff88810987c000, ffff88810987e000) The buggy address belongs to the physical page: page:ffffea0004261e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x109878 head:ffffea0004261e00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 ffffea00043f4800 dead000000000002 ffff888100043500 raw: 0000000000000000 0000000000020002 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 285, tgid 285 (syz-executor), ts 26075346633, free_ts 0 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2643 prep_new_page+0x1c/0x110 mm/page_alloc.c:2650 get_page_from_freelist+0x2c7b/0x2cf0 mm/page_alloc.c:4554 __alloc_pages+0x1c3/0x450 mm/page_alloc.c:5868 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1 allocate_slab mm/slub.c:1962 [inline] new_slab+0x98/0x3d0 mm/slub.c:2015 ___slab_alloc+0x6f6/0xb50 mm/slub.c:3203 __slab_alloc+0x5e/0xa0 mm/slub.c:3302 slab_alloc_node mm/slub.c:3387 [inline] __kmem_cache_alloc_node+0x203/0x2c0 mm/slub.c:3462 __do_kmalloc_node mm/slab_common.c:937 [inline] __kmalloc_node+0xa1/0x1e0 mm/slab_common.c:945 kmalloc_node include/linux/slab.h:589 [inline] kvmalloc_node+0x294/0x480 mm/util.c:592 kvmalloc include/linux/slab.h:716 [inline] kvmalloc_array include/linux/slab.h:734 [inline] __ptr_ring_init_queue_alloc include/linux/ptr_ring.h:471 [inline] ptr_ring_init include/linux/ptr_ring.h:489 [inline] wg_packet_queue_init+0x95/0x320 drivers/net/wireguard/queueing.c:32 wg_newlink+0x43c/0x7a0 drivers/net/wireguard/device.c:357 rtnl_newlink_create net/core/rtnetlink.c:3422 [inline] __rtnl_newlink net/core/rtnetlink.c:3642 [inline] rtnl_newlink+0x14b9/0x2030 net/core/rtnetlink.c:3655 rtnetlink_rcv_msg+0x9f4/0xcf0 net/core/rtnetlink.c:6153 netlink_rcv_skb+0x1f2/0x440 net/netlink/af_netlink.c:2521 page_owner free stack trace missing Memory state around the buggy address: ffff88810987c900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88810987c980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88810987ca00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88810987ca80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88810987cb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 1 PID: 7317 Comm: syz.1.2066 Tainted: G B syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:__queue_work+0x575/0xd30 kernel/workqueue.c:-1 Code: 39 2b 0f 84 b9 00 00 00 e8 a8 dd 28 00 4c 89 ff e8 a0 70 ac 03 49 bc 00 00 00 00 00 fc ff df 4c 8b 6d d0 4c 89 e8 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 ef e8 2c 42 6d 00 49 8b 7d 00 e8 83 6c RSP: 0000:ffffc9000c087bb0 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 000000007fffffff RCX: ffff88810ffca880 RDX: 0000000000000100 RSI: 000000007fffffff RDI: 000000007fffffff RBP: ffffc9000c087c48 R08: fffffffffffffffb R09: 0000000000000007 R10: ffffed102130f939 R11: 1ffff1102130f939 R12: dffffc0000000000 R13: 0000000000000000 R14: ffff88810987c9c8 R15: 0000000000000008 FS: 000055558cc27500(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9410ea5b37 CR3: 0000000137f8f000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: delayed_work_timer_fn+0x61/0x80 kernel/workqueue.c:1653 call_timer_fn+0x46/0x2a0 kernel/time/timer.c:1510 expire_timers kernel/time/timer.c:1550 [inline] __run_timers+0x667/0x9a0 kernel/time/timer.c:1826 run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1839 handle_softirqs+0x1d7/0x600 kernel/softirq.c:642 __do_softirq kernel/softirq.c:680 [inline] invoke_softirq kernel/softirq.c:497 [inline] __irq_exit_rcu+0x52/0xf0 kernel/softirq.c:729 irq_exit_rcu+0x9/0x10 kernel/softirq.c:741 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x58/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0033:0x7ff6ed24d9d0 Code: 41 5e c3 0f 1f 80 00 00 00 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 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 36 00 89 f0 4c 8d 05 19 26 36 RSP: 002b:00007ffe46f69e38 EFLAGS: 00000246 RAX: 000000000000088d RBX: 00007ff6ee0f5720 RCX: 0000000000006bed RDX: ffffffff83b77c23 RSI: ffffffff83b77b10 RDI: 00000000000000ff RBP: ffffffff83b77b10 R08: 00007ff6ed5c5f40 R09: 00007ff6ed5b2000 R10: 00007ff6ebdf9008 R11: 00000000000000ff R12: 00000000000000ff R13: 0000000000000000 R14: ffffffff83b77c23 R15: 0000000000006bed Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:__queue_work+0x575/0xd30 kernel/workqueue.c:-1 Code: 39 2b 0f 84 b9 00 00 00 e8 a8 dd 28 00 4c 89 ff e8 a0 70 ac 03 49 bc 00 00 00 00 00 fc ff df 4c 8b 6d d0 4c 89 e8 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 ef e8 2c 42 6d 00 49 8b 7d 00 e8 83 6c RSP: 0000:ffffc9000c087bb0 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 000000007fffffff RCX: ffff88810ffca880 RDX: 0000000000000100 RSI: 000000007fffffff RDI: 000000007fffffff RBP: ffffc9000c087c48 R08: fffffffffffffffb R09: 0000000000000007 R10: ffffed102130f939 R11: 1ffff1102130f939 R12: dffffc0000000000 R13: 0000000000000000 R14: ffff88810987c9c8 R15: 0000000000000008 FS: 000055558cc27500(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9410ea5b37 CR3: 0000000137f8f000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 39 2b cmp %ebp,(%rbx) 2: 0f 84 b9 00 00 00 je 0xc1 8: e8 a8 dd 28 00 call 0x28ddb5 d: 4c 89 ff mov %r15,%rdi 10: e8 a0 70 ac 03 call 0x3ac70b5 15: 49 bc 00 00 00 00 00 movabs $0xdffffc0000000000,%r12 1c: fc ff df 1f: 4c 8b 6d d0 mov -0x30(%rbp),%r13 23: 4c 89 e8 mov %r13,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) <-- trapping instruction 2f: 74 08 je 0x39 31: 4c 89 ef mov %r13,%rdi 34: e8 2c 42 6d 00 call 0x6d4265 39: 49 8b 7d 00 mov 0x0(%r13),%rdi 3d: e8 .byte 0xe8 3e: 83 .byte 0x83 3f: 6c insb (%dx),%es:(%rdi)