==================================================================
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 ffff8881255b0a00 by task syz.5.1199/4573
CPU: 1 PID: 4573 Comm: syz.5.1199 Tainted: G W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
__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
asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:244 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x8/0x80 kernel/kcov.c:320
Code: 89 44 11 20 5d c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 b8 80 f8 fd 6f 55 48 89 e5 48 8b 45 08 <65> 48 8b 0d f0 fb 90 7e 65 8b 15 f1 fb 90 7e 81 e2 00 01 ff 00 74
RSP: 0000:ffffc900007afc70 EFLAGS: 00000246
RAX: ffffffff81ab9d8c RBX: ffff8881385fb160 RCX: ffff88811bcfe540
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900007afc70 R08: ffffc900007afdcf R09: ffffc900007afd8c
R10: dffffc0000000000 R11: fffff520000f5fba R12: 0000000000000000
R13: dffffc0000000001 R14: 000000010a4af067 R15: 000000010a4af001
handle_mm_fault+0xd6c/0x26c0 arch/x86/include/asm/pgtable.h:-1
do_user_addr_fault+0x905/0x1050 arch/x86/mm/fault.c:1321
handle_page_fault arch/x86/mm/fault.c:1464 [inline]
exc_page_fault+0x51/0xb0 arch/x86/mm/fault.c:1517
asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7f304de53b0e
Code: c1 49 39 4f 08 72 54 8d 4d ff 85 ed 74 3b 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 39 f0 72 1b 4d 8b 07 49 89 c1 49 29 f1 <47> 0f b6 0c 08 45 84 c9 74 08 45 88 0c 00 49 8b 47 10 48 83 c0 01
RSP: 002b:00007f304ef25470 EFLAGS: 00010206
RAX: 0000000001268001 RBX: 00007f304ef25530 RCX: 000000000000003e
RDX: 0000000000000005 RSI: 0000000000000001 RDI: 00007f304ef255d0
RBP: 0000000000000102 R08: 00007f30445f8000 R09: 0000000001268000
R10: 0000000000000000 R11: 00007f304ef25540 R12: 0000000000000001
R13: 00007f304e0522c0 R14: 0000000000000000 R15: 00007f304ef255d0
Allocated by task 4498:
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
kasan_save_alloc_info+0x25/0x30 mm/kasan/generic.c:505
____kasan_kmalloc mm/kasan/common.c:380 [inline]
__kasan_kmalloc+0x95/0xb0 mm/kasan/common.c:389
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+0x3c8/0xa20 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:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Freed by task 4502:
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
kasan_save_free_info+0x31/0x50 mm/kasan/generic.c:516
____kasan_slab_free+0x132/0x180 mm/kasan/common.c:242
__kasan_slab_free+0x11/0x20 mm/kasan/common.c:250
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:1465 [inline]
hci_dev_cmd+0x279/0x740 net/bluetooth/hci_core.c:795
hci_sock_ioctl+0x41e/0x7f0 net/bluetooth/hci_sock.c:1096
sock_do_ioctl+0x114/0x330 net/socket.c:1191
sock_ioctl+0x4bd/0x710 net/socket.c:1310
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:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Last potentially related work creation:
kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46
__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+0x35b/0x740 net/bluetooth/hci_core.c:749
hci_sock_ioctl+0x41e/0x7f0 net/bluetooth/hci_sock.c:1096
sock_do_ioctl+0x114/0x330 net/socket.c:1191
sock_ioctl+0x4bd/0x710 net/socket.c:1310
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:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Second to last potentially related work creation:
kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46
__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 ffff8881255b0000
which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 2560 bytes inside of
8192-byte region [ffff8881255b0000, ffff8881255b2000)
The buggy address belongs to the physical page:
page:ffffea0004956c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1255b0
head:ffffea0004956c00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head|zone=1)
raw: 4000000000010200 ffffea0004b87800 dead000000000006 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 0x1d2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 4087, tgid 4086 (syz.9.1052), ts 177291584094, free_ts 177188746359
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2670
prep_new_page+0x1c/0x110 mm/page_alloc.c:2677
get_page_from_freelist+0x2d12/0x2d80 mm/page_alloc.c:4583
__alloc_pages+0x1d9/0x480 mm/page_alloc.c:5897
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+0xa1/0x1e0 mm/slab_common.c:951
kmalloc include/linux/slab.h:568 [inline]
f2fs_kmalloc fs/f2fs/f2fs.h:3371 [inline]
f2fs_kzalloc fs/f2fs/f2fs.h:3390 [inline]
read_all_xattrs+0xf8/0x660 fs/f2fs/xattr.c:398
__f2fs_setxattr+0x1e9/0x12f0 fs/f2fs/xattr.c:655
f2fs_setxattr+0x1f1/0x510 fs/f2fs/xattr.c:820
f2fs_initxattrs+0xa6/0x110 fs/f2fs/xattr.c:146
security_inode_init_security+0x2a9/0x3d0 security/security.c:1133
f2fs_init_security+0x34/0x40 fs/f2fs/xattr.c:158
page last free stack trace:
reset_page_owner include/linux/page_owner.h:26 [inline]
free_pages_prepare mm/page_alloc.c:1578 [inline]
free_pcp_prepare mm/page_alloc.c:1652 [inline]
free_unref_page_prepare+0x742/0x750 mm/page_alloc.c:3618
free_unref_page+0x95/0x540 mm/page_alloc.c:3716
free_the_page mm/page_alloc.c:863 [inline]
__free_pages+0x67/0x100 mm/page_alloc.c:5986
free_pages+0x82/0x90 mm/page_alloc.c:5997
free_pg_vec net/packet/af_packet.c:4374 [inline]
packet_set_ring+0x1999/0x24a0 net/packet/af_packet.c:4593
packet_release+0x737/0xcb0 net/packet/af_packet.c:3201
__sock_release net/socket.c:652 [inline]
sock_close+0xf1/0x290 net/socket.c:1389
__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:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Memory state around the buggy address:
ffff8881255b0900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881255b0980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881255b0a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881255b0a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881255b0b00: 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: 4573 Comm: syz.5.1199 Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:__queue_work+0x575/0xd30 kernel/workqueue.c:-1
Code: 39 2b 0f 84 b9 00 00 00 e8 48 46 29 00 4c 89 ff e8 60 70 b8 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 9c 78 6e 00 49 8b 7d 00 e8 f3 6b
RSP: 0000:ffffc900001b0c70 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 000000007fffffff RCX: ffff88811bcfe540
RDX: 0000000000000100 RSI: 000000007fffffff RDI: 000000007fffffff
RBP: ffffc900001b0d08 R08: 0000000000000007 R09: fffffffffffffffb
R10: dffffc0000000000 R11: ffffed1024ab6139 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff8881255b09c8 R15: 0000000000000008
FS: 00007f304ef266c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3045860000 CR3: 0000000124088000 CR4: 00000000003526a0
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: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
asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:244 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x8/0x80 kernel/kcov.c:320
Code: 89 44 11 20 5d c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 b8 80 f8 fd 6f 55 48 89 e5 48 8b 45 08 <65> 48 8b 0d f0 fb 90 7e 65 8b 15 f1 fb 90 7e 81 e2 00 01 ff 00 74
RSP: 0000:ffffc900007afc70 EFLAGS: 00000246
RAX: ffffffff81ab9d8c RBX: ffff8881385fb160 RCX: ffff88811bcfe540
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900007afc70 R08: ffffc900007afdcf R09: ffffc900007afd8c
R10: dffffc0000000000 R11: fffff520000f5fba R12: 0000000000000000
R13: dffffc0000000001 R14: 000000010a4af067 R15: 000000010a4af001
handle_mm_fault+0xd6c/0x26c0 arch/x86/include/asm/pgtable.h:-1
do_user_addr_fault+0x905/0x1050 arch/x86/mm/fault.c:1321
handle_page_fault arch/x86/mm/fault.c:1464 [inline]
exc_page_fault+0x51/0xb0 arch/x86/mm/fault.c:1517
asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7f304de53b0e
Code: c1 49 39 4f 08 72 54 8d 4d ff 85 ed 74 3b 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 39 f0 72 1b 4d 8b 07 49 89 c1 49 29 f1 <47> 0f b6 0c 08 45 84 c9 74 08 45 88 0c 00 49 8b 47 10 48 83 c0 01
RSP: 002b:00007f304ef25470 EFLAGS: 00010206
RAX: 0000000001268001 RBX: 00007f304ef25530 RCX: 000000000000003e
RDX: 0000000000000005 RSI: 0000000000000001 RDI: 00007f304ef255d0
RBP: 0000000000000102 R08: 00007f30445f8000 R09: 0000000001268000
R10: 0000000000000000 R11: 00007f304ef25540 R12: 0000000000000001
R13: 00007f304e0522c0 R14: 0000000000000000 R15: 00007f304ef255d0
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 48 46 29 00 4c 89 ff e8 60 70 b8 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 9c 78 6e 00 49 8b 7d 00 e8 f3 6b
RSP: 0000:ffffc900001b0c70 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 000000007fffffff RCX: ffff88811bcfe540
RDX: 0000000000000100 RSI: 000000007fffffff RDI: 000000007fffffff
RBP: ffffc900001b0d08 R08: 0000000000000007 R09: fffffffffffffffb
R10: dffffc0000000000 R11: ffffed1024ab6139 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff8881255b09c8 R15: 0000000000000008
FS: 00007f304ef266c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3045860000 CR3: 0000000124088000 CR4: 00000000003526a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 89 44 11 20 mov %eax,0x20(%rcx,%rdx,1)
4: 5d pop %rbp
5: c3 ret
6: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1)
d: 00 00 00
10: 66 90 xchg %ax,%ax
12: 90 nop
13: 90 nop
14: 90 nop
15: 90 nop
16: 90 nop
17: 90 nop
18: 90 nop
19: 90 nop
1a: 90 nop
1b: 90 nop
1c: 90 nop
1d: b8 80 f8 fd 6f mov $0x6ffdf880,%eax
22: 55 push %rbp
23: 48 89 e5 mov %rsp,%rbp
26: 48 8b 45 08 mov 0x8(%rbp),%rax
* 2a: 65 48 8b 0d f0 fb 90 mov %gs:0x7e90fbf0(%rip),%rcx # 0x7e90fc22 <-- trapping instruction
31: 7e
32: 65 8b 15 f1 fb 90 7e mov %gs:0x7e90fbf1(%rip),%edx # 0x7e90fc2a
39: 81 e2 00 01 ff 00 and $0xff0100,%edx
3f: 74 .byte 0x74