================================================================== 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 ffff888112658a00 by task swapper/1/0 CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106 print_address_description+0x71/0x200 mm/kasan/report.c:316 print_report+0x4a/0x60 mm/kasan/report.c:420 kasan_report+0x122/0x150 mm/kasan/report.c:524 __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+0xa9/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:default_idle+0xf/0x20 arch/x86/kernel/process.c:742 Code: e9 47 ff ff ff 00 00 cc cc 00 00 90 90 90 90 90 90 90 90 90 90 90 b8 0c 67 40 a5 55 48 89 e5 66 90 0f 00 2d d3 3f 52 00 fb f4 <5d> c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 90 90 90 90 90 RSP: 0018:ffffc90000147dd8 EFLAGS: 00000257 RAX: ffff8881f7100000 RBX: ffff888100331440 RCX: ef870f27e6d2b000 RDX: 0000000000000001 RSI: ffffffff85aa0e80 RDI: ffffffff85aa0e40 RBP: ffffc90000147dd8 R08: dffffc0000000000 R09: ffffed103ee26917 R10: 0000000000000000 R11: ffffffff84f3f260 R12: 0000000000000000 R13: 0000000000000000 R14: ffff888100331440 R15: dffffc0000000000 arch_cpu_idle+0x1c/0x20 arch/x86/kernel/process.c:733 default_idle_call+0x71/0x1d0 kernel/sched/idle.c:109 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1a7/0x520 kernel/sched/idle.c:303 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:401 start_secondary+0x119/0x120 arch/x86/kernel/smpboot.c:281 secondary_startup_64_no_verify+0xce/0xdb Allocated by task 5270: 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 5270: 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:1750 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1776 slab_free mm/slub.c:3712 [inline] __kmem_cache_free+0xb7/0x1b0 mm/slub.c:3728 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+0x628/0x720 net/bluetooth/hci_core.c:-1 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 ffff888112658000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 2560 bytes inside of 8192-byte region [ffff888112658000, ffff88811265a000) The buggy address belongs to the physical page: page:ffffea0004499600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x112658 head:ffffea0004499600 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 ffffea0004b66600 dead000000000003 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 0x1d2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5159, tgid 5157 (syz.6.2002), ts 116084229785, free_ts 116046354158 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:1967 [inline] new_slab+0x98/0x3d0 mm/slub.c:2020 ___slab_alloc+0x6bd/0xb20 mm/slub.c:3177 __slab_alloc+0x5e/0xa0 mm/slub.c:3263 slab_alloc_node mm/slub.c:3348 [inline] __kmem_cache_alloc_node+0x203/0x2c0 mm/slub.c:3423 __do_kmalloc_node mm/slab_common.c:937 [inline] __kmalloc_node_track_caller+0xa0/0x1e0 mm/slab_common.c:958 kmalloc_reserve net/core/skbuff.c:449 [inline] pskb_expand_head+0x1b0/0x1210 net/core/skbuff.c:1851 __pskb_pull_tail+0xb1/0x1570 net/core/skbuff.c:2398 __skb_linearize include/linux/skbuff.h:3764 [inline] skb_linearize include/linux/skbuff.h:3776 [inline] tipc_msg_reverse+0x78/0x940 net/tipc/msg.c:631 tipc_sk_filter_rcv+0xbf3/0x2c80 net/tipc/socket.c:2376 tipc_sk_enqueue net/tipc/socket.c:2445 [inline] tipc_sk_rcv+0x7d9/0x2cc0 net/tipc/socket.c:2497 tipc_sk_mcast_rcv+0xe08/0xed0 net/tipc/socket.c:1268 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1551 [inline] free_pcp_prepare mm/page_alloc.c:1625 [inline] free_unref_page_prepare+0x742/0x750 mm/page_alloc.c:3589 free_unref_page+0x8f/0x530 mm/page_alloc.c:3687 free_the_page mm/page_alloc.c:836 [inline] __free_pages+0x67/0x100 mm/page_alloc.c:5957 __free_slab+0xca/0x1a0 mm/slub.c:2044 free_slab mm/slub.c:2059 [inline] discard_slab mm/slub.c:2065 [inline] __unfreeze_partials+0x160/0x190 mm/slub.c:2614 put_cpu_partial+0xa9/0x100 mm/slub.c:2690 __slab_free+0x1c4/0x280 mm/slub.c:3589 do_slab_free mm/slub.c:3666 [inline] ___cache_free+0xbf/0xd0 mm/slub.c:3722 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0xc6/0x140 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x14a/0x170 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x24/0x80 mm/kasan/common.c:310 kasan_slab_alloc include/linux/kasan.h:202 [inline] slab_post_alloc_hook+0x4f/0x2d0 mm/slab.h:768 slab_alloc_node mm/slub.c:3382 [inline] slab_alloc mm/slub.c:3392 [inline] __kmem_cache_alloc_lru mm/slub.c:3399 [inline] kmem_cache_alloc+0x16e/0x330 mm/slub.c:3408 getname_flags+0xb9/0x500 fs/namei.c:139 user_path_at_empty+0x30/0x1c0 fs/namei.c:2903 user_path_at include/linux/namei.h:57 [inline] do_utimes_path fs/utimes.c:94 [inline] do_utimes+0x138/0x2a0 fs/utimes.c:144 Memory state around the buggy address: ffff888112658900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888112658980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888112658a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888112658a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888112658b00: 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: 5479 Comm: syz-executor Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:__queue_work+0x575/0xd30 kernel/workqueue.c:-1 Code: 39 2b 0f 84 b9 00 00 00 e8 88 dc 28 00 4c 89 ff e8 70 db 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 4c 4a 6d 00 49 8b 7d 00 e8 53 d7 RSP: 0018:ffffc900001b0c70 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 000000007fffffff RCX: ffff888120023cc0 RDX: 0000000000000100 RSI: 000000007fffffff RDI: 000000007fffffff RBP: ffffc900001b0d08 R08: fffffffffffffffb R09: 0000000000000007 R10: ffffed10224cb139 R11: 1ffff110224cb139 R12: dffffc0000000000 R13: 0000000000000000 R14: ffff8881126589c8 R15: 0000000000000008 FS: 0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6fad769f98 CR3: 0000000128437000 CR4: 00000000003506a0 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+0xa9/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:stack_trace_consume_entry+0x13f/0x290 kernel/stacktrace.c:95 Code: 8b 75 c0 49 89 37 41 8b 18 41 0f b6 44 15 00 84 c0 0f 85 3d 01 00 00 41 3b 19 0f 92 c0 48 83 c4 20 5b 41 5c 41 5d 41 5e 41 5f <5d> c3 44 89 c1 80 e1 07 80 c1 03 38 c1 0f 8c e0 fe ff ff 49 89 fe RSP: 0018:ffffc9000f12f2b8 EFLAGS: 00000286 RAX: 0000000000000001 RBX: ffffc9000f12f380 RCX: 000000000f12f300 RDX: dffffc0000000000 RSI: ffffffff814252e0 RDI: ffffc9000f12f380 RBP: ffffc9000f12f2b8 R08: ffffc9000f12f390 R09: ffffc9000f12f388 R10: 000000000000000a R11: 1ffff92001e25e59 R12: ffff888120023cc0 R13: 1ffff92001e25e84 R14: ffffffff8160e2f0 R15: ffffc9000f12f2c8 arch_stack_walk+0x118/0x150 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122 save_stack+0xf3/0x1e0 mm/page_owner.c:147 __reset_page_owner+0x54/0x190 mm/page_owner.c:168 reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1551 [inline] free_pcp_prepare mm/page_alloc.c:1625 [inline] free_unref_page_prepare+0x742/0x750 mm/page_alloc.c:3589 free_unref_page+0x8f/0x530 mm/page_alloc.c:3687 free_the_page mm/page_alloc.c:836 [inline] __free_pages+0x67/0x100 mm/page_alloc.c:5957 __vunmap+0x9af/0xb70 mm/vmalloc.c:2739 __vfree mm/vmalloc.c:2788 [inline] vfree+0x61/0x90 mm/vmalloc.c:2819 kcov_put kernel/kcov.c:437 [inline] kcov_close+0x2b/0x50 kernel/kcov.c:533 __fput+0x1fc/0x8f0 fs/file_table.c:320 ____fput+0x15/0x20 fs/file_table.c:348 task_work_run+0x1db/0x240 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0xa25/0x2650 kernel/exit.c:886 do_group_exit+0x210/0x2d0 kernel/exit.c:1028 get_signal+0x13b5/0x1520 kernel/signal.c:2889 arch_do_signal_or_restart+0xb0/0x1030 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x7a/0xb0 kernel/entry/common.c:174 exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f1019390d03 Code: Unable to access opcode bytes at 0x7f1019390cd9. RSP: 002b:00007fff76528bc8 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: 0000000000000068 RBX: 00007f101a114620 RCX: 00007f1019390d03 RDX: 0000000000000068 RSI: 00007f101a114670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007fff76528be4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f101a114670 R15: 0000000000000000 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 88 dc 28 00 4c 89 ff e8 70 db 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 4c 4a 6d 00 49 8b 7d 00 e8 53 d7 RSP: 0018:ffffc900001b0c70 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 000000007fffffff RCX: ffff888120023cc0 RDX: 0000000000000100 RSI: 000000007fffffff RDI: 000000007fffffff RBP: ffffc900001b0d08 R08: fffffffffffffffb R09: 0000000000000007 R10: ffffed10224cb139 R11: 1ffff110224cb139 R12: dffffc0000000000 R13: 0000000000000000 R14: ffff8881126589c8 R15: 0000000000000008 FS: 0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6fad769f98 CR3: 0000000128437000 CR4: 00000000003506a0 ---------------- Code disassembly (best guess): 0: e9 47 ff ff ff jmp 0xffffff4c 5: 00 00 add %al,(%rax) 7: cc int3 8: cc int3 9: 00 00 add %al,(%rax) b: 90 nop c: 90 nop d: 90 nop e: 90 nop f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: b8 0c 67 40 a5 mov $0xa540670c,%eax 1b: 55 push %rbp 1c: 48 89 e5 mov %rsp,%rbp 1f: 66 90 xchg %ax,%ax 21: 0f 00 2d d3 3f 52 00 verw 0x523fd3(%rip) # 0x523ffb 28: fb sti 29: f4 hlt * 2a: 5d pop %rbp <-- trapping instruction 2b: c3 ret 2c: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 33: 00 00 00 36: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop 3f: 90 nop