==================================================================
BUG: KASAN: use-after-free in hlist_move_list include/linux/list.h:1014 [inline]
BUG: KASAN: use-after-free in collect_expired_timers kernel/time/timer.c:1625 [inline]
BUG: KASAN: use-after-free in __run_timers+0x340/0x9f0 kernel/time/timer.c:1861
Write of size 8 at addr ffff88811e80ca00 by task syz.8.566/1849

CPU: 1 PID: 1849 Comm: syz.8.566 Tainted: G        W          syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <IRQ>
 __dump_stack+0x21/0x24 lib/dump_stack.c:88
 dump_stack_lvl+0x110/0x170 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_move_list include/linux/list.h:1014 [inline]
 collect_expired_timers kernel/time/timer.c:1625 [inline]
 __run_timers+0x340/0x9f0 kernel/time/timer.c:1861
 run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1888
 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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__sanitizer_cov_trace_switch+0x17/0xe0 kernel/kcov.c:332
Code: 20 5d c3 90 90 90 90 90 90 90 90 90 90 90 b8 00 1e 12 56 48 8b 4e 08 48 83 c1 f8 48 c1 c1 3d 48 83 f9 08 0f 92 c0 b2 8b d2 ea <20> c2 80 fa 01 0f 85 b7 00 00 00 48 8b 06 48 85 c0 0f 84 ab 00 00
RSP: 0018:ffffc900011d7a60 EFLAGS: 00000a06
RAX: ffffffff82692301 RBX: ffffc900011d7d20 RCX: 0000000000000003
RDX: ffffc900036a2011 RSI: ffffffff871bc4f0 RDI: 0000000000000014
RBP: ffffc900011d7bd0 R08: ffffc900011d7c2f R09: 1ffff9200023af85
R10: dffffc0000000000 R11: fffff5200023af86 R12: ffffc900011d7bf0
R13: dffffc0000000000 R14: 0000000000000014 R15: 0000000000000014
 chacha_block_generic+0x5b/0xd20 lib/crypto/chacha.c:83
 chacha20_block include/crypto/chacha.h:36 [inline]
 get_random_bytes_user+0x19a/0x3b0 drivers/char/random.c:428
 __do_sys_getrandom drivers/char/random.c:1335 [inline]
 __se_sys_getrandom drivers/char/random.c:1308 [inline]
 __x64_sys_getrandom+0x1a2/0x2a0 drivers/char/random.c:1308
 x64_sys_call+0x25f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:319
 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
RIP: 0033:0x7fddf5d9acb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fddf6be0028 EFLAGS: 00000246 ORIG_RAX: 000000000000013e
RAX: ffffffffffffffda RBX: 00007fddf6015fa0 RCX: 00007fddf5d9acb9
RDX: 0000000000000000 RSI: 00000000ffffff9a RDI: 0000200000000240
RBP: 00007fddf5e08bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fddf6016038 R14: 00007fddf6015fa0 R15: 00007ffe6cdc39c8
 </TASK>

Allocated by task 1682:
 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:1505 [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 1676:
 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_free_dev+0x1c/0x20 net/bluetooth/hci_core.c:2556
 hci_uart_tty_close+0x1a3/0x230 drivers/bluetooth/hci_ldisc.c:555
 tty_ldisc_close drivers/tty/tty_ldisc.c:456 [inline]
 tty_ldisc_kill+0x10f/0x1f0 drivers/tty/tty_ldisc.c:608
 tty_ldisc_release+0x1a5/0x200 drivers/tty/tty_ldisc.c:776
 tty_release_struct+0x29/0xe0 drivers/tty/tty_io.c:1689
 tty_release+0xbfd/0x1210 drivers/tty/tty_io.c:1860
 __fput+0x1fc/0x8f0 fs/file_table.c:320
 ____fput+0x15/0x20 fs/file_table.c:348
 task_work_run+0x1e1/0x250 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0x9b/0xb0 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0x87/0xd0 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

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+0xde/0x150 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+0xa7f/0xd30 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+0x648/0x740 net/bluetooth/hci_core.c:-1
 hci_sock_ioctl+0x41e/0x7f0 net/bluetooth/hci_sock.c:1096
 sock_do_ioctl+0x114/0x330 net/socket.c:1194
 sock_ioctl+0x4ca/0x720 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+0xde/0x150 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+0xa29/0x11e0 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 ffff88811e80c000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 2560 bytes inside of
 8192-byte region [ffff88811e80c000, ffff88811e80e000)

The buggy address belongs to the physical page:
page:ffffea00047a0200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11e808
head:ffffea00047a0200 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head|zone=1)
raw: 4000000000010200 0000000000000000 dead000000000001 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 0x52a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 148, tgid 148 (mkdir), ts 5383763630, 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+0x2d12/0x2d80 mm/page_alloc.c:4554
 __alloc_pages+0x1d9/0x480 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
 kmalloc_trace+0x29/0xb0 mm/slab_common.c:1028
 kmalloc include/linux/slab.h:563 [inline]
 audit_log_d_path+0xc6/0x240 kernel/audit.c:2151
 dump_common_audit_data security/lsm_audit.c:223 [inline]
 common_lsm_audit+0x1de/0x1730 security/lsm_audit.c:457
 slow_avc_audit+0x1c4/0x240 security/selinux/avc.c:804
 avc_audit security/selinux/include/avc.h:136 [inline]
 avc_has_perm+0x1fb/0x250 security/selinux/avc.c:1201
 inode_has_perm security/selinux/hooks.c:1638 [inline]
 path_has_perm security/selinux/hooks.c:1671 [inline]
 selinux_inode_getattr+0x2c3/0x3d0 security/selinux/hooks.c:3166
 security_inode_getattr+0xe7/0x140 security/security.c:1361
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88811e80c900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88811e80c980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88811e80ca00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff88811e80ca80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88811e80cb00: 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: 1849 Comm: syz.8.566 Tainted: G    B   W          syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__queue_work+0x575/0xd30 kernel/workqueue.c:-1
Code: 39 2b 0f 84 b9 00 00 00 e8 a8 44 29 00 4c 89 ff e8 a0 80 b7 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 3c 71 6e 00 49 8b 7d 00 e8 33 7c
RSP: 0018:ffffc900001b0c70 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 000000007fffffff RCX: ffff88810e7d3cc0
RDX: 0000000000000100 RSI: 000000007fffffff RDI: 000000007fffffff
RBP: ffffc900001b0d08 R08: 0000000000000007 R09: fffffffffffffffb
R10: dffffc0000000000 R11: ffffed1023d01939 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff88811e80c9c8 R15: 0000000000000008
FS:  00007fddf6be06c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000060e000 CR3: 000000011e140000 CR4: 00000000003526a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 delayed_work_timer_fn+0x61/0x80 kernel/workqueue.c:1653
 call_timer_fn+0x46/0x2a0 kernel/time/timer.c:1553
 expire_timers kernel/time/timer.c:1599 [inline]
 __run_timers+0x689/0x9f0 kernel/time/timer.c:1875
 run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1888
 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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__sanitizer_cov_trace_switch+0x17/0xe0 kernel/kcov.c:332
Code: 20 5d c3 90 90 90 90 90 90 90 90 90 90 90 b8 00 1e 12 56 48 8b 4e 08 48 83 c1 f8 48 c1 c1 3d 48 83 f9 08 0f 92 c0 b2 8b d2 ea <20> c2 80 fa 01 0f 85 b7 00 00 00 48 8b 06 48 85 c0 0f 84 ab 00 00
RSP: 0018:ffffc900011d7a60 EFLAGS: 00000a06
RAX: ffffffff82692301 RBX: ffffc900011d7d20 RCX: 0000000000000003
RDX: ffffc900036a2011 RSI: ffffffff871bc4f0 RDI: 0000000000000014
RBP: ffffc900011d7bd0 R08: ffffc900011d7c2f R09: 1ffff9200023af85
R10: dffffc0000000000 R11: fffff5200023af86 R12: ffffc900011d7bf0
R13: dffffc0000000000 R14: 0000000000000014 R15: 0000000000000014
 chacha_block_generic+0x5b/0xd20 lib/crypto/chacha.c:83
 chacha20_block include/crypto/chacha.h:36 [inline]
 get_random_bytes_user+0x19a/0x3b0 drivers/char/random.c:428
 __do_sys_getrandom drivers/char/random.c:1335 [inline]
 __se_sys_getrandom drivers/char/random.c:1308 [inline]
 __x64_sys_getrandom+0x1a2/0x2a0 drivers/char/random.c:1308
 x64_sys_call+0x25f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:319
 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
RIP: 0033:0x7fddf5d9acb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fddf6be0028 EFLAGS: 00000246 ORIG_RAX: 000000000000013e
RAX: ffffffffffffffda RBX: 00007fddf6015fa0 RCX: 00007fddf5d9acb9
RDX: 0000000000000000 RSI: 00000000ffffff9a RDI: 0000200000000240
RBP: 00007fddf5e08bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fddf6016038 R14: 00007fddf6015fa0 R15: 00007ffe6cdc39c8
 </TASK>
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 44 29 00 4c 89 ff e8 a0 80 b7 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 3c 71 6e 00 49 8b 7d 00 e8 33 7c
RSP: 0018:ffffc900001b0c70 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 000000007fffffff RCX: ffff88810e7d3cc0
RDX: 0000000000000100 RSI: 000000007fffffff RDI: 000000007fffffff
RBP: ffffc900001b0d08 R08: 0000000000000007 R09: fffffffffffffffb
R10: dffffc0000000000 R11: ffffed1023d01939 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff88811e80c9c8 R15: 0000000000000008
FS:  00007fddf6be06c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000060e000 CR3: 000000011e140000 CR4: 00000000003526a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	20 5d c3             	and    %bl,-0x3d(%rbp)
   3:	90                   	nop
   4:	90                   	nop
   5:	90                   	nop
   6:	90                   	nop
   7:	90                   	nop
   8:	90                   	nop
   9:	90                   	nop
   a:	90                   	nop
   b:	90                   	nop
   c:	90                   	nop
   d:	90                   	nop
   e:	b8 00 1e 12 56       	mov    $0x56121e00,%eax
  13:	48 8b 4e 08          	mov    0x8(%rsi),%rcx
  17:	48 83 c1 f8          	add    $0xfffffffffffffff8,%rcx
  1b:	48 c1 c1 3d          	rol    $0x3d,%rcx
  1f:	48 83 f9 08          	cmp    $0x8,%rcx
  23:	0f 92 c0             	setb   %al
  26:	b2 8b                	mov    $0x8b,%dl
  28:	d2 ea                	shr    %cl,%dl
* 2a:	20 c2                	and    %al,%dl <-- trapping instruction
  2c:	80 fa 01             	cmp    $0x1,%dl
  2f:	0f 85 b7 00 00 00    	jne    0xec
  35:	48 8b 06             	mov    (%rsi),%rax
  38:	48 85 c0             	test   %rax,%rax
  3b:	0f                   	.byte 0xf
  3c:	84                   	.byte 0x84
  3d:	ab                   	stos   %eax,%es:(%rdi)