======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G L
------------------------------------------------------
syz.2.3037/16815 is trying to acquire lock:
ffffffff8e9aa860 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:317 [inline]
ffffffff8e9aa860 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:4489 [inline]
ffffffff8e9aa860 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:4843 [inline]
ffffffff8e9aa860 (fs_reclaim){+.+.}-{0:0}, at: kmem_cache_alloc_noprof+0x4c/0x6e0 mm/slub.c:4873
but task is already holding lock:
ffff88801cecf220 (&root->kernfs_iattr_rwsem){++++}-{4:4}, at: kernfs_iop_setattr+0x88/0x130 fs/kernfs/inode.c:123
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #8 (&root->kernfs_iattr_rwsem){++++}-{4:4}:
down_read+0x99/0x460 kernel/locking/rwsem.c:1537
kernfs_iop_permission+0x6e/0xc0 fs/kernfs/inode.c:289
do_inode_permission fs/namei.c:578 [inline]
inode_permission+0x3f1/0x620 fs/namei.c:648
cgroup_may_write+0xaa/0x120 kernel/cgroup/cgroup.c:5308
cgroup_procs_write_permission kernel/cgroup/cgroup.c:5328 [inline]
cgroup_attach_permissions+0x1b8/0x770 kernel/cgroup/cgroup.c:5351
__cgroup_procs_write+0x2d4/0x730 kernel/cgroup/cgroup.c:5394
cgroup_threads_write+0x23/0x50 kernel/cgroup/cgroup.c:5424
cgroup_file_write+0x1e9/0x790 kernel/cgroup/cgroup.c:4310
kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:352
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x6ac/0x1070 fs/read_write.c:688
ksys_write+0x12a/0x250 fs/read_write.c:740
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0xe3/0x8c0 arch/x86/entry/syscall_32.c:307
do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
-> #7 (cpu_hotplug_lock){++++}-{0:0}:
percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline]
percpu_down_read include/linux/percpu-rwsem.h:77 [inline]
cpus_read_lock+0x42/0x170 kernel/cpu.c:490
static_key_slow_inc+0x12/0x30 kernel/jump_label.c:190
fl_create+0x7fb/0xd10 net/ipv6/ip6_flowlabel.c:457
ipv6_flowlabel_get net/ipv6/ip6_flowlabel.c:637 [inline]
ipv6_flowlabel_opt+0x519/0x2d40 net/ipv6/ip6_flowlabel.c:740
do_ipv6_setsockopt+0x1944/0x4400 net/ipv6/ipv6_sockglue.c:936
ipv6_setsockopt+0xcb/0x170 net/ipv6/ipv6_sockglue.c:973
tcp_setsockopt+0xa7/0x100 net/ipv4/tcp.c:4218
do_sock_setsockopt+0xf3/0x1d0 net/socket.c:2322
__sys_setsockopt+0x119/0x190 net/socket.c:2347
__do_sys_setsockopt net/socket.c:2353 [inline]
__se_sys_setsockopt net/socket.c:2350 [inline]
__ia32_sys_setsockopt+0xbc/0x160 net/socket.c:2350
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0xe3/0x8c0 arch/x86/entry/syscall_32.c:307
do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
-> #6 (sk_lock-AF_INET6){+.+.}-{0:0}:
lock_sock_nested+0x41/0xf0 net/core/sock.c:3780
lock_sock include/net/sock.h:1709 [inline]
inet_shutdown+0x67/0x410 net/ipv4/af_inet.c:919
nbd_mark_nsock_dead+0xae/0x5c0 drivers/block/nbd.c:318
sock_shutdown+0x16b/0x200 drivers/block/nbd.c:411
nbd_clear_sock drivers/block/nbd.c:1427 [inline]
nbd_config_put+0x1eb/0x750 drivers/block/nbd.c:1451
nbd_release+0xb7/0x190 drivers/block/nbd.c:1756
blkdev_put_whole+0xb0/0xf0 block/bdev.c:737
bdev_release+0x47f/0x6d0 block/bdev.c:1160
blkdev_release+0x15/0x20 block/fops.c:705
__fput+0x3ff/0xb40 fs/file_table.c:469
task_work_run+0x150/0x240 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
exit_to_user_mode_loop+0x100/0x4a0 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
__do_fast_syscall_32+0x578/0x8c0 arch/x86/entry/syscall_32.c:310
do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
-> #5 (&nsock->tx_lock){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:614 [inline]
__mutex_lock+0x1a2/0x1b90 kernel/locking/mutex.c:776
nbd_handle_cmd drivers/block/nbd.c:1143 [inline]
nbd_queue_rq+0x428/0x1080 drivers/block/nbd.c:1207
blk_mq_dispatch_rq_list+0x422/0x1e70 block/blk-mq.c:2148
__blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
__blk_mq_sched_dispatch_requests+0xcea/0x1620 block/blk-mq-sched.c:307
blk_mq_sched_dispatch_requests+0xd7/0x1c0 block/blk-mq-sched.c:329
blk_mq_run_hw_queue+0x23c/0x670 block/blk-mq.c:2386
blk_mq_dispatch_list+0x51d/0x1360 block/blk-mq.c:2949
blk_mq_flush_plug_list block/blk-mq.c:2997 [inline]
blk_mq_flush_plug_list+0x130/0x600 block/blk-mq.c:2969
__blk_flush_plug+0x2c4/0x4b0 block/blk-core.c:1230
blk_finish_plug block/blk-core.c:1257 [inline]
__submit_bio+0x584/0x6c0 block/blk-core.c:649
__submit_bio_noacct_mq block/blk-core.c:722 [inline]
submit_bio_noacct_nocheck+0x562/0xc10 block/blk-core.c:753
submit_bio_noacct+0xd17/0x2010 block/blk-core.c:884
blk_crypto_submit_bio include/linux/blk-crypto.h:203 [inline]
submit_bh_wbc+0x59c/0x770 fs/buffer.c:2821
submit_bh fs/buffer.c:2826 [inline]
block_read_full_folio+0x264/0x8e0 fs/buffer.c:2444
filemap_read_folio+0xfc/0x3b0 mm/filemap.c:2501
do_read_cache_folio+0x2d7/0x6b0 mm/filemap.c:4101
read_mapping_folio include/linux/pagemap.h:1028 [inline]
read_part_sector+0xd1/0x370 block/partitions/core.c:723
adfspart_check_ICS+0x93/0x910 block/partitions/acorn.c:360
check_partition block/partitions/core.c:142 [inline]
blk_add_partitions block/partitions/core.c:590 [inline]
bdev_disk_changed+0x7f8/0xc80 block/partitions/core.c:694
blkdev_get_whole+0x187/0x290 block/bdev.c:764
bdev_open+0x2c7/0xe40 block/bdev.c:973
blkdev_open+0x34e/0x4f0 block/fops.c:697
do_dentry_open+0x6d8/0x1660 fs/open.c:949
vfs_open+0x82/0x3f0 fs/open.c:1081
do_open fs/namei.c:4671 [inline]
path_openat+0x208c/0x31a0 fs/namei.c:4830
do_file_open+0x20e/0x430 fs/namei.c:4859
do_sys_openat2+0x10d/0x1e0 fs/open.c:1366
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x12d/0x210 fs/open.c:1383
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #4 (&cmd->lock){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:614 [inline]
__mutex_lock+0x1a2/0x1b90 kernel/locking/mutex.c:776
nbd_queue_rq+0xba/0x1080 drivers/block/nbd.c:1199
blk_mq_dispatch_rq_list+0x422/0x1e70 block/blk-mq.c:2148
__blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
__blk_mq_sched_dispatch_requests+0xcea/0x1620 block/blk-mq-sched.c:307
blk_mq_sched_dispatch_requests+0xd7/0x1c0 block/blk-mq-sched.c:329
blk_mq_run_hw_queue+0x23c/0x670 block/blk-mq.c:2386
blk_mq_dispatch_list+0x51d/0x1360 block/blk-mq.c:2949
blk_mq_flush_plug_list block/blk-mq.c:2997 [inline]
blk_mq_flush_plug_list+0x130/0x600 block/blk-mq.c:2969
__blk_flush_plug+0x2c4/0x4b0 block/blk-core.c:1230
blk_finish_plug block/blk-core.c:1257 [inline]
__submit_bio+0x584/0x6c0 block/blk-core.c:649
__submit_bio_noacct_mq block/blk-core.c:722 [inline]
submit_bio_noacct_nocheck+0x562/0xc10 block/blk-core.c:753
submit_bio_noacct+0xd17/0x2010 block/blk-core.c:884
blk_crypto_submit_bio include/linux/blk-crypto.h:203 [inline]
submit_bh_wbc+0x59c/0x770 fs/buffer.c:2821
submit_bh fs/buffer.c:2826 [inline]
block_read_full_folio+0x264/0x8e0 fs/buffer.c:2444
filemap_read_folio+0xfc/0x3b0 mm/filemap.c:2501
do_read_cache_folio+0x2d7/0x6b0 mm/filemap.c:4101
read_mapping_folio include/linux/pagemap.h:1028 [inline]
read_part_sector+0xd1/0x370 block/partitions/core.c:723
adfspart_check_ICS+0x93/0x910 block/partitions/acorn.c:360
check_partition block/partitions/core.c:142 [inline]
blk_add_partitions block/partitions/core.c:590 [inline]
bdev_disk_changed+0x7f8/0xc80 block/partitions/core.c:694
blkdev_get_whole+0x187/0x290 block/bdev.c:764
bdev_open+0x2c7/0xe40 block/bdev.c:973
blkdev_open+0x34e/0x4f0 block/fops.c:697
do_dentry_open+0x6d8/0x1660 fs/open.c:949
vfs_open+0x82/0x3f0 fs/open.c:1081
do_open fs/namei.c:4671 [inline]
path_openat+0x208c/0x31a0 fs/namei.c:4830
do_file_open+0x20e/0x430 fs/namei.c:4859
do_sys_openat2+0x10d/0x1e0 fs/open.c:1366
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x12d/0x210 fs/open.c:1383
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #3 (set->srcu){.+.+}-{0:0}:
srcu_lock_sync include/linux/srcu.h:199 [inline]
__synchronize_srcu+0xa2/0x300 kernel/rcu/srcutree.c:1481
blk_mq_wait_quiesce_done block/blk-mq.c:284 [inline]
blk_mq_wait_quiesce_done block/blk-mq.c:281 [inline]
blk_mq_quiesce_queue block/blk-mq.c:304 [inline]
blk_mq_quiesce_queue+0x149/0x1c0 block/blk-mq.c:299
elevator_switch+0x17b/0x7e0 block/elevator.c:576
elevator_change+0x352/0x530 block/elevator.c:681
elevator_set_default+0x29e/0x360 block/elevator.c:754
blk_register_queue+0x412/0x590 block/blk-sysfs.c:946
__add_disk+0x73f/0xe40 block/genhd.c:528
add_disk_fwnode+0x118/0x5c0 block/genhd.c:597
add_disk include/linux/blkdev.h:785 [inline]
nbd_dev_add+0x77a/0xb10 drivers/block/nbd.c:1984
nbd_init+0x291/0x2b0 drivers/block/nbd.c:2692
do_one_initcall+0x11d/0x760 init/main.c:1382
do_initcall_level init/main.c:1444 [inline]
do_initcalls init/main.c:1460 [inline]
do_basic_setup init/main.c:1479 [inline]
kernel_init_freeable+0x6e5/0x7a0 init/main.c:1692
kernel_init+0x1f/0x1e0 init/main.c:1582
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
-> #2 (&q->elevator_lock){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:614 [inline]
__mutex_lock+0x1a2/0x1b90 kernel/locking/mutex.c:776
elevator_change+0x1bc/0x530 block/elevator.c:679
elevator_set_none+0x92/0xf0 block/elevator.c:769
blk_mq_elv_switch_none block/blk-mq.c:5110 [inline]
__blk_mq_update_nr_hw_queues block/blk-mq.c:5155 [inline]
blk_mq_update_nr_hw_queues+0x4c1/0x15f0 block/blk-mq.c:5220
nbd_start_device+0x1a6/0xbd0 drivers/block/nbd.c:1489
nbd_genl_connect+0xff2/0x1a40 drivers/block/nbd.c:2239
genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1114
genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
____sys_sendmsg+0x9e1/0xb70 net/socket.c:2592
___sys_sendmsg+0x190/0x1e0 net/socket.c:2646
__sys_sendmsg+0x170/0x220 net/socket.c:2678
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0xe3/0x8c0 arch/x86/entry/syscall_32.c:307
do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
-> #1 (&q->q_usage_counter(io)#49){++++}-{0:0}:
blk_alloc_queue+0x610/0x790 block/blk-core.c:461
blk_mq_alloc_queue+0x174/0x290 block/blk-mq.c:4429
__blk_mq_alloc_disk+0x29/0x120 block/blk-mq.c:4476
nbd_dev_add+0x492/0xb10 drivers/block/nbd.c:1954
nbd_init+0x291/0x2b0 drivers/block/nbd.c:2692
do_one_initcall+0x11d/0x760 init/main.c:1382
do_initcall_level init/main.c:1444 [inline]
do_initcalls init/main.c:1460 [inline]
do_basic_setup init/main.c:1479 [inline]
kernel_init_freeable+0x6e5/0x7a0 init/main.c:1692
kernel_init+0x1f/0x1e0 init/main.c:1582
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
-> #0 (fs_reclaim){+.+.}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x14b8/0x2630 kernel/locking/lockdep.c:5237
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1cf/0x380 kernel/locking/lockdep.c:5825
__fs_reclaim_acquire mm/page_alloc.c:4348 [inline]
fs_reclaim_acquire+0xc4/0x100 mm/page_alloc.c:4362
might_alloc include/linux/sched/mm.h:317 [inline]
slab_pre_alloc_hook mm/slub.c:4489 [inline]
slab_alloc_node mm/slub.c:4843 [inline]
kmem_cache_alloc_noprof+0x4c/0x6e0 mm/slub.c:4873
__kernfs_iattrs+0x126/0x400 fs/kernfs/inode.c:36
kernfs_iattrs fs/kernfs/inode.c:61 [inline]
__kernfs_setattr+0x4d/0x3c0 fs/kernfs/inode.c:74
kernfs_iop_setattr+0xda/0x130 fs/kernfs/inode.c:128
notify_change+0xb25/0x1330 fs/attr.c:556
chmod_common+0x245/0x4d0 fs/open.c:639
do_fchmodat+0x10a/0x1b0 fs/open.c:684
__do_sys_chmod fs/open.c:708 [inline]
__se_sys_chmod fs/open.c:706 [inline]
__ia32_sys_chmod+0x5c/0x80 fs/open.c:706
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0xe3/0x8c0 arch/x86/entry/syscall_32.c:307
do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
other info that might help us debug this:
Chain exists of:
fs_reclaim --> cpu_hotplug_lock --> &root->kernfs_iattr_rwsem
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&root->kernfs_iattr_rwsem);
lock(cpu_hotplug_lock);
lock(&root->kernfs_iattr_rwsem);
lock(fs_reclaim);
*** DEADLOCK ***
3 locks held by syz.2.3037/16815:
#0: ffff88802ae08420 (sb_writers#9){.+.+}-{0:0}, at: chmod_common+0x107/0x4d0 fs/open.c:627
#1: ffff888000558640 (&sb->s_type->i_mutex_key#19){+.+.}-{4:4}, at: inode_lock_killable include/linux/fs.h:1033 [inline]
#1: ffff888000558640 (&sb->s_type->i_mutex_key#19){+.+.}-{4:4}, at: chmod_common+0x177/0x4d0 fs/open.c:631
#2: ffff88801cecf220 (&root->kernfs_iattr_rwsem){++++}-{4:4}, at: kernfs_iop_setattr+0x88/0x130 fs/kernfs/inode.c:123
stack backtrace:
CPU: 0 UID: 0 PID: 16815 Comm: syz.2.3037 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_circular_bug.cold+0x178/0x1c7 kernel/locking/lockdep.c:2043
check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2175
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x14b8/0x2630 kernel/locking/lockdep.c:5237
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1cf/0x380 kernel/locking/lockdep.c:5825
__fs_reclaim_acquire mm/page_alloc.c:4348 [inline]
fs_reclaim_acquire+0xc4/0x100 mm/page_alloc.c:4362
might_alloc include/linux/sched/mm.h:317 [inline]
slab_pre_alloc_hook mm/slub.c:4489 [inline]
slab_alloc_node mm/slub.c:4843 [inline]
kmem_cache_alloc_noprof+0x4c/0x6e0 mm/slub.c:4873
__kernfs_iattrs+0x126/0x400 fs/kernfs/inode.c:36
kernfs_iattrs fs/kernfs/inode.c:61 [inline]
__kernfs_setattr+0x4d/0x3c0 fs/kernfs/inode.c:74
kernfs_iop_setattr+0xda/0x130 fs/kernfs/inode.c:128
notify_change+0xb25/0x1330 fs/attr.c:556
chmod_common+0x245/0x4d0 fs/open.c:639
do_fchmodat+0x10a/0x1b0 fs/open.c:684
__do_sys_chmod fs/open.c:708 [inline]
__se_sys_chmod fs/open.c:706 [inline]
__ia32_sys_chmod+0x5c/0x80 fs/open.c:706
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0xe3/0x8c0 arch/x86/entry/syscall_32.c:307
do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf6fdef6c
Code: d2 74 05 c1 e8 0c 89 02 8b 5d fc 31 c0 c9 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 2e 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 58 b8
RSP: 002b:00000000f53cd50c EFLAGS: 00000292 ORIG_RAX: 000000000000000f
RAX: ffffffffffffffda RBX: 0000000080000040 RCX: 000000009526c7ac
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
----------------
Code disassembly (best guess):
0: d2 74 05 c1 shlb %cl,-0x3f(%rbp,%rax,1)
4: e8 0c 89 02 8b call 0x8b028915
9: 5d pop %rbp
a: fc cld
b: 31 c0 xor %eax,%eax
d: c9 leave
e: c3 ret
f: 90 nop
10: 90 nop
11: 90 nop
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: 90 nop
1e: 0f 1f 00 nopl (%rax)
21: 51 push %rcx
22: 52 push %rdx
23: 55 push %rbp
24: 89 e5 mov %esp,%ebp
26: 0f 34 sysenter
28: cd 80 int $0x80
* 2a: 5d pop %rbp <-- trapping instruction
2b: 5a pop %rdx
2c: 59 pop %rcx
2d: c3 ret
2e: 90 nop
2f: 2e 8d b4 26 00 00 00 cs lea 0x0(%rsi,%riz,1),%esi
36: 00
37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi
3e: 58 pop %rax
3f: b8 .byte 0xb8