INFO: task syz-executor.1:14558 blocked for more than 143 seconds. Not tainted 5.15.0-rc6-next-20211020-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.1 state:D stack:25048 pid:14558 ppid: 6557 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:4965 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6246 schedule+0xd2/0x260 kernel/sched/core.c:6319 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6378 __mutex_lock_common kernel/locking/mutex.c:672 [inline] __mutex_lock+0xa32/0x12f0 kernel/locking/mutex.c:732 tun_detach drivers/net/tun.c:684 [inline] tun_chr_close+0x3a/0x180 drivers/net/tun.c:3397 __fput+0x286/0x9f0 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0xc14/0x2b40 kernel/exit.c:832 do_group_exit+0x125/0x310 kernel/exit.c:929 get_signal+0x47d/0x2160 kernel/signal.c:2833 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:863 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f83234d0a39 RSP: 002b:00007f8320a46218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f83235d3f68 RCX: 00007f83234d0a39 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f83235d3f68 RBP: 00007f83235d3f60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f83235d3f6c R13: 00007ffdd9a2ba6f R14: 00007f8320a46300 R15: 0000000000022000 INFO: task syz-executor.0:24510 can't die for more than 143 seconds. task:syz-executor.0 state:D stack:27432 pid:24510 ppid: 6555 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4965 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6246 schedule+0xd2/0x260 kernel/sched/core.c:6319 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6378 __mutex_lock_common kernel/locking/mutex.c:672 [inline] __mutex_lock+0xa32/0x12f0 kernel/locking/mutex.c:732 nl80211_pre_doit+0x23/0x620 net/wireless/nl80211.c:15153 genl_family_rcv_msg_doit+0x1ee/0x320 net/netlink/genetlink.c:726 genl_family_rcv_msg net/netlink/genetlink.c:775 [inline] genl_rcv_msg+0x328/0x580 net/netlink/genetlink.c:792 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2491 genl_rcv+0x24/0x40 net/netlink/genetlink.c:803 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x86d/0xda0 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 __sys_sendto+0x21c/0x320 net/socket.c:2036 __do_sys_sendto net/socket.c:2048 [inline] __se_sys_sendto net/socket.c:2044 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2044 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f32d0d0b7fc RSP: 002b:00007f32ce2ccf80 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f32ce2cd0f0 RCX: 00007f32d0d0b7fc RDX: 0000000000000024 RSI: 00007f32ce2cd140 RDI: 0000000000000004 RBP: 0000000000000000 R08: 00007f32ce2ccfd4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 00007f32ce2cd140 R14: 0000000000000004 R15: 0000000000000000 INFO: task syz-executor.0:24510 blocked for more than 143 seconds. Not tainted 5.15.0-rc6-next-20211020-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:27432 pid:24510 ppid: 6555 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4965 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6246 schedule+0xd2/0x260 kernel/sched/core.c:6319 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6378 __mutex_lock_common kernel/locking/mutex.c:672 [inline] __mutex_lock+0xa32/0x12f0 kernel/locking/mutex.c:732 nl80211_pre_doit+0x23/0x620 net/wireless/nl80211.c:15153 genl_family_rcv_msg_doit+0x1ee/0x320 net/netlink/genetlink.c:726 genl_family_rcv_msg net/netlink/genetlink.c:775 [inline] genl_rcv_msg+0x328/0x580 net/netlink/genetlink.c:792 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2491 genl_rcv+0x24/0x40 net/netlink/genetlink.c:803 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x86d/0xda0 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 __sys_sendto+0x21c/0x320 net/socket.c:2036 __do_sys_sendto net/socket.c:2048 [inline] __se_sys_sendto net/socket.c:2044 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2044 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f32d0d0b7fc RSP: 002b:00007f32ce2ccf80 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f32ce2cd0f0 RCX: 00007f32d0d0b7fc RDX: 0000000000000024 RSI: 00007f32ce2cd140 RDI: 0000000000000004 RBP: 0000000000000000 R08: 00007f32ce2ccfd4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 00007f32ce2cd140 R14: 0000000000000004 R15: 0000000000000000 INFO: task syz-executor.3:24527 can't die for more than 144 seconds. task:syz-executor.3 state:D stack:27432 pid:24527 ppid: 6561 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4965 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6246 schedule+0xd2/0x260 kernel/sched/core.c:6319 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6378 __mutex_lock_common kernel/locking/mutex.c:672 [inline] __mutex_lock+0xa32/0x12f0 kernel/locking/mutex.c:732 nl80211_pre_doit+0x23/0x620 net/wireless/nl80211.c:15153 genl_family_rcv_msg_doit+0x1ee/0x320 net/netlink/genetlink.c:726 genl_family_rcv_msg net/netlink/genetlink.c:775 [inline] genl_rcv_msg+0x328/0x580 net/netlink/genetlink.c:792 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2491 genl_rcv+0x24/0x40 net/netlink/genetlink.c:803 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x86d/0xda0 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 __sys_sendto+0x21c/0x320 net/socket.c:2036 __do_sys_sendto net/socket.c:2048 [inline] __se_sys_sendto net/socket.c:2044 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2044 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fa8bf4f07fc RSP: 002b:00007fa8bcab1f80 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007fa8bcab20f0 RCX: 00007fa8bf4f07fc RDX: 0000000000000024 RSI: 00007fa8bcab2140 RDI: 0000000000000004 RBP: 0000000000000000 R08: 00007fa8bcab1fd4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 00007fa8bcab2140 R14: 0000000000000004 R15: 0000000000000000 INFO: task syz-executor.3:24527 blocked for more than 144 seconds. Not tainted 5.15.0-rc6-next-20211020-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.3 state:D stack:27432 pid:24527 ppid: 6561 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4965 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6246 schedule+0xd2/0x260 kernel/sched/core.c:6319 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6378 __mutex_lock_common kernel/locking/mutex.c:672 [inline] __mutex_lock+0xa32/0x12f0 kernel/locking/mutex.c:732 nl80211_pre_doit+0x23/0x620 net/wireless/nl80211.c:15153 genl_family_rcv_msg_doit+0x1ee/0x320 net/netlink/genetlink.c:726 genl_family_rcv_msg net/netlink/genetlink.c:775 [inline] genl_rcv_msg+0x328/0x580 net/netlink/genetlink.c:792 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2491 genl_rcv+0x24/0x40 net/netlink/genetlink.c:803 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x86d/0xda0 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 __sys_sendto+0x21c/0x320 net/socket.c:2036 __do_sys_sendto net/socket.c:2048 [inline] __se_sys_sendto net/socket.c:2044 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2044 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fa8bf4f07fc RSP: 002b:00007fa8bcab1f80 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007fa8bcab20f0 RCX: 00007fa8bf4f07fc RDX: 0000000000000024 RSI: 00007fa8bcab2140 RDI: 0000000000000004 RBP: 0000000000000000 R08: 00007fa8bcab1fd4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 00007fa8bcab2140 R14: 0000000000000004 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8bb835a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 1 lock held by in:imklog/6235: 2 locks held by kworker/u4:6/8696: 1 lock held by syz-executor.1/14558: #0: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:684 [inline] #0: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3a/0x180 drivers/net/tun.c:3397 2 locks held by kworker/u4:14/18125: #0: ffff8880b9d39a98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2b/0x120 kernel/sched/core.c:478 #1: ffff8880b9d279c8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x3a6/0x490 kernel/sched/psi.c:880 4 locks held by kworker/u4:15/18128: #0: ffff888140753138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888140753138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888140753138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff888140753138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:634 [inline] #0: ffff888140753138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:661 [inline] #0: ffff888140753138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2268 #1: ffffc900187ffdb0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2272 #2: ffffffff8d2e9390 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xb00 net/core/net_namespace.c:555 #3: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_delete_nets+0x8e/0x5b0 net/ipv4/ip_tunnel.c:1118 3 locks held by kworker/1:15/20672: #0: ffff888021d83d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888021d83d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888021d83d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff888021d83d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:634 [inline] #0: ffff888021d83d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:661 [inline] #0: ffff888021d83d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2268 #1: ffffc900164bfdb0 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2272 #2: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4590 1 lock held by systemd-udevd/23087: #0: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x470/0xee0 net/core/dev_ioctl.c:521 1 lock held by systemd-udevd/23094: #0: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x470/0xee0 net/core/dev_ioctl.c:521 1 lock held by systemd-udevd/23227: #0: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x470/0xee0 net/core/dev_ioctl.c:521 1 lock held by systemd-udevd/23232: #0: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x470/0xee0 net/core/dev_ioctl.c:521 2 locks held by syz-executor.0/24510: #0: ffffffff8d38f050 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:802 #1: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: nl80211_pre_doit+0x23/0x620 net/wireless/nl80211.c:15153 2 locks held by syz-executor.3/24527: #0: ffffffff8d38f050 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:802 #1: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: nl80211_pre_doit+0x23/0x620 net/wireless/nl80211.c:15153 1 lock held by syz-executor.2/24554: #0: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3be/0xb80 net/core/rtnetlink.c:5569 1 lock held by syz-executor.5/24555: #0: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3be/0xb80 net/core/rtnetlink.c:5569 1 lock held by syz-executor.4/24556: #0: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3be/0xb80 net/core/rtnetlink.c:5569 1 lock held by syz-executor.1/24600: #0: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d2fcb68 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3be/0xb80 net/core/rtnetlink.c:5569 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.0-rc6-next-20211020-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:254 [inline] watchdog+0xcb7/0xed0 kernel/hung_task.c:339 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 18125 Comm: kworker/u4:14 Not tainted 5.15.0-rc6-next-20211020-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:__local_bh_enable_ip+0x83/0x120 kernel/softirq.c:378 Code: c0 74 53 9c 58 fa f6 c4 02 75 5a 65 8b 05 85 d2 bb 7e 25 00 ff 00 00 3d 00 02 00 00 74 4e 83 eb 01 f7 db 65 01 1d 6d d2 bb 7e <65> 8b 05 66 d2 bb 7e a9 00 ff ff 00 74 45 bf 01 00 00 00 e8 35 36 RSP: 0018:ffffc900187dfc08 EFLAGS: 00000083 RAX: 0000000000000001 RBX: 00000000fffffe00 RCX: 1ffffffff2092938 RDX: 0000000000000000 RSI: 0000000000000201 RDI: 0000000000000000 RBP: ffffffff88e98495 R08: 0000000000000000 R09: ffff888019930743 R10: ffffffff817db6fd R11: 0000000000000000 R12: ffff88807c0997a8 R13: ffff88807c098c80 R14: dffffc0000000000 R15: ffffffff88e98590 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c000295000 CR3: 000000000b88e000 CR4: 00000000003506e0 Call Trace: spin_unlock_bh include/linux/spinlock.h:412 [inline] batadv_nc_purge_paths+0x2a5/0x3a0 net/batman-adv/network-coding.c:473 batadv_nc_worker+0x8f9/0xfa0 net/batman-adv/network-coding.c:722 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2297 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: c0 74 53 9c 58 shlb $0x58,-0x64(%rbx,%rdx,2) 5: fa cli 6: f6 c4 02 test $0x2,%ah 9: 75 5a jne 0x65 b: 65 8b 05 85 d2 bb 7e mov %gs:0x7ebbd285(%rip),%eax # 0x7ebbd297 12: 25 00 ff 00 00 and $0xff00,%eax 17: 3d 00 02 00 00 cmp $0x200,%eax 1c: 74 4e je 0x6c 1e: 83 eb 01 sub $0x1,%ebx 21: f7 db neg %ebx 23: 65 01 1d 6d d2 bb 7e add %ebx,%gs:0x7ebbd26d(%rip) # 0x7ebbd297 * 2a: 65 8b 05 66 d2 bb 7e mov %gs:0x7ebbd266(%rip),%eax # 0x7ebbd297 <-- trapping instruction 31: a9 00 ff ff 00 test $0xffff00,%eax 36: 74 45 je 0x7d 38: bf 01 00 00 00 mov $0x1,%edi 3d: e8 .byte 0xe8 3e: 35 .byte 0x35 3f: 36 ss