====================================================== WARNING: possible circular locking dependency detected 5.10.207 #1 Not tainted ------------------------------------------------------ syz-executor.4/7025 is trying to acquire lock: ffff888018208ae8 ((work_completion)(&hdev->tx_work)){+.+.}-{0:0}, at: __flush_work+0xdd/0xa90 kernel/workqueue.c:3050 but task is already holding lock: ffff888018208f40 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0xef/0x1240 net/bluetooth/hci_core.c:1734 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&hdev->req_lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:968 [inline] __mutex_lock+0x13d/0x10b0 kernel/locking/mutex.c:1109 hci_dev_do_close+0xef/0x1240 net/bluetooth/hci_core.c:1734 hci_rfkill_set_block+0x166/0x1a0 net/bluetooth/hci_core.c:2223 rfkill_set_block+0x1fd/0x540 net/rfkill/core.c:341 rfkill_fop_write+0x253/0x4b0 net/rfkill/core.c:1240 vfs_write+0x29a/0xa70 fs/read_write.c:603 ksys_write+0x1f6/0x260 fs/read_write.c:658 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x62/0xc7 -> #2 (rfkill_global_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:968 [inline] __mutex_lock+0x13d/0x10b0 kernel/locking/mutex.c:1109 rfkill_register+0x36/0xa10 net/rfkill/core.c:1016 hci_register_dev+0x42e/0xc00 net/bluetooth/hci_core.c:3773 __vhci_create_device+0x2c8/0x5c0 drivers/bluetooth/hci_vhci.c:129 vhci_create_device drivers/bluetooth/hci_vhci.c:153 [inline] vhci_open_timeout+0x38/0x50 drivers/bluetooth/hci_vhci.c:310 process_one_work+0x9a9/0x14b0 kernel/workqueue.c:2282 worker_thread+0x61d/0x1310 kernel/workqueue.c:2428 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 kthread+0x38f/0x470 kernel/kthread.c:313 ret_from_fork+0x22/0x30 arch/x86/entry/entry_64.S:299 CPU: 1 PID: 7030 Comm: syz-executor.1 Not tainted 5.10.207 #1 -> #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 ( Call Trace: &data->open_mutex __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x107/0x167 lib/dump_stack.c:118 ){+.+.}-{3:3} fail_dump lib/fault-inject.c:52 [inline] should_fail.cold+0x5/0xa lib/fault-inject.c:146 : __mutex_lock_common kernel/locking/mutex.c:968 [inline] __mutex_lock+0x13d/0x10b0 kernel/locking/mutex.c:1109 vhci_send_frame+0x63/0xa0 drivers/bluetooth/hci_vhci.c:71 should_failslab+0x5/0x20 mm/slab_common.c:1193 hci_send_frame+0x1b9/0x320 net/bluetooth/hci_core.c:4060 slab_pre_alloc_hook mm/slab.h:515 [inline] slab_alloc_node mm/slub.c:2821 [inline] __kmalloc_node+0x76/0x420 mm/slub.c:4015 hci_sched_acl_pkt net/bluetooth/hci_core.c:4585 [inline] hci_sched_acl net/bluetooth/hci_core.c:4670 [inline] hci_tx_work+0x10af/0x1660 net/bluetooth/hci_core.c:4741 kmalloc_node include/linux/slab.h:575 [inline] kvmalloc_node+0xc0/0x170 mm/util.c:607 process_one_work+0x9a9/0x14b0 kernel/workqueue.c:2282 kvmalloc include/linux/mm.h:765 [inline] kvmalloc_array include/linux/mm.h:783 [inline] __ptr_ring_init_queue_alloc include/linux/ptr_ring.h:471 [inline] ptr_ring_init include/linux/ptr_ring.h:489 [inline] skb_array_init include/linux/skb_array.h:182 [inline] pfifo_fast_init+0xea/0x3d0 net/sched/sch_generic.c:779 worker_thread+0x61d/0x1310 kernel/workqueue.c:2428 kthread+0x38f/0x470 kernel/kthread.c:313 qdisc_create_dflt+0x103/0x370 net/sched/sch_generic.c:931 ret_from_fork+0x22/0x30 arch/x86/entry/entry_64.S:299 attach_one_default_qdisc net/sched/sch_generic.c:1087 [inline] netdev_for_each_tx_queue include/linux/netdevice.h:2286 [inline] attach_default_qdiscs net/sched/sch_generic.c:1105 [inline] dev_activate+0x7c3/0xd70 net/sched/sch_generic.c:1164 -> #0 __dev_open+0x38a/0x4e0 net/core/dev.c:1544 ( (work_completion)(&hdev->tx_work) ){+.+.}-{0:0} __dev_change_flags+0x521/0x6e0 net/core/dev.c:8507 : check_prev_add kernel/locking/lockdep.c:2988 [inline] check_prevs_add kernel/locking/lockdep.c:3113 [inline] validate_chain kernel/locking/lockdep.c:3729 [inline] __lock_acquire+0x29e7/0x5b00 kernel/locking/lockdep.c:4955 lock_acquire kernel/locking/lockdep.c:5566 [inline] lock_acquire+0x197/0x470 kernel/locking/lockdep.c:5531 __flush_work+0x105/0xa90 kernel/workqueue.c:3053 dev_change_flags+0x8a/0x160 net/core/dev.c:8578 hci_dev_do_close+0x131/0x1240 net/bluetooth/hci_core.c:1745 devinet_ioctl+0x14de/0x1db0 net/ipv4/devinet.c:1143 hci_rfkill_set_block+0x166/0x1a0 net/bluetooth/hci_core.c:2223 rfkill_set_block+0x1fd/0x540 net/rfkill/core.c:341 inet_ioctl+0x34f/0x390 net/ipv4/af_inet.c:969 rfkill_fop_write+0x253/0x4b0 net/rfkill/core.c:1240 vfs_write+0x29a/0xa70 fs/read_write.c:603 ksys_write+0x1f6/0x260 fs/read_write.c:658 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x62/0xc7 other info that might help us debug this: Chain exists of: packet_ioctl+0xb3/0x260 net/packet/af_packet.c:4206 (work_completion)(&hdev->tx_work) sock_do_ioctl+0xd3/0x300 net/socket.c:1064 --> rfkill_global_mutex --> &hdev->req_lock Possible unsafe locking scenario: sock_ioctl+0x3ea/0x700 net/socket.c:1204 CPU0 CPU1 ---- ---- lock( &hdev->req_lock vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x19a/0x210 fs/ioctl.c:739 ); do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 lock( entry_SYSCALL_64_after_hwframe+0x62/0xc7 rfkill_global_mutex RIP: 0033:0x7f86bc084b19 ); Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48 lock( RSP: 002b:00007f86b95fa188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 &hdev->req_lock RAX: ffffffffffffffda RBX: 00007f86bc197f60 RCX: 00007f86bc084b19 RDX: 00000000200001c0 RSI: 0000000000008914 RDI: 0000000000000004 ); RBP: 00007f86b95fa1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 lock( R13: 00007ffe4669ad8f R14: 00007f86b95fa300 R15: 0000000000022000 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 (work_completion)(&hdev->tx_work)); *** DEADLOCK *** 2 locks held by syz-executor.4/7025: CPU: 1 PID: 7032 Comm: syz-executor.5 Not tainted 5.10.207 #1 #0: Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: ffffffff85619628 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x107/0x167 lib/dump_stack.c:118 ( fail_dump lib/fault-inject.c:52 [inline] should_fail.cold+0x5/0xa lib/fault-inject.c:146 rfkill_global_mutex ){+.+.}-{3:3} should_failslab+0x5/0x20 mm/slab_common.c:1193 , at: rfkill_fop_write+0xff/0x4b0 net/rfkill/core.c:1232 slab_pre_alloc_hook mm/slab.h:515 [inline] slab_alloc_node mm/slub.c:2821 [inline] slab_alloc mm/slub.c:2904 [inline] kmem_cache_alloc+0x5b/0x310 mm/slub.c:2909 mem_pool_alloc mm/kmemleak.c:423 [inline] create_object.isra.0+0x3a/0xa20 mm/kmemleak.c:578 #1: kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline] slab_post_alloc_hook mm/slab.h:534 [inline] slab_alloc_node mm/slub.c:2896 [inline] kmem_cache_alloc_node+0x169/0x330 mm/slub.c:2932 ffff888018208f40 __alloc_skb+0x6d/0x5b0 net/core/skbuff.c:198 ( alloc_skb include/linux/skbuff.h:1102 [inline] alloc_skb_with_frags+0x92/0x570 net/core/skbuff.c:5907 &hdev->req_lock){+.+.}-{3:3} , at: hci_dev_do_close+0xef/0x1240 net/bluetooth/hci_core.c:1734 stack backtrace: sock_alloc_send_pskb+0x7af/0x930 net/core/sock.c:2363 unix_dgram_sendmsg+0x3d6/0x1a10 net/unix/af_unix.c:1740 sock_sendmsg_nosec net/socket.c:651 [inline] __sock_sendmsg net/socket.c:663 [inline] sock_sendmsg+0x2af/0x310 net/socket.c:685 sock_no_sendpage+0x12c/0x1a0 net/core/sock.c:2867 kernel_sendpage.part.0+0x146/0x290 net/socket.c:3546 kernel_sendpage net/socket.c:3543 [inline] sock_sendpage+0xe5/0x140 net/socket.c:961 pipe_to_sendpage+0x2af/0x380 fs/splice.c:364 splice_from_pipe_feed fs/splice.c:418 [inline] __splice_from_pipe+0x43d/0x890 fs/splice.c:562 splice_from_pipe fs/splice.c:597 [inline] generic_splice_sendpage+0xd5/0x140 fs/splice.c:743 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0x10f/0x170 fs/splice.c:933 splice_direct_to_actor+0x387/0x980 fs/splice.c:888 do_splice_direct+0x1c4/0x290 fs/splice.c:976 do_sendfile+0x553/0x1090 fs/read_write.c:1257 __do_sys_sendfile64 fs/read_write.c:1318 [inline] __se_sys_sendfile64 fs/read_write.c:1304 [inline] __x64_sys_sendfile64+0x1d1/0x210 fs/read_write.c:1304 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x62/0xc7 RIP: 0033:0x7f2ae505db19 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2ae25d3188 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f2ae5170f60 RCX: 00007f2ae505db19 RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000004 RBP: 00007f2ae25d31d0 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000b052 R11: 0000000000000246 R12: 0000000000000002 R13: 00007fff580a8eaf R14: 00007f2ae25d3300 R15: 0000000000022000 CPU: 0 PID: 7025 Comm: syz-executor.4 Not tainted 5.10.207 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x107/0x167 lib/dump_stack.c:118 check_noncircular+0x263/0x2e0 kernel/locking/lockdep.c:2123 check_prev_add kernel/locking/lockdep.c:2988 [inline] check_prevs_add kernel/locking/lockdep.c:3113 [inline] validate_chain kernel/locking/lockdep.c:3729 [inline] __lock_acquire+0x29e7/0x5b00 kernel/locking/lockdep.c:4955 lock_acquire kernel/locking/lockdep.c:5566 [inline] lock_acquire+0x197/0x470 kernel/locking/lockdep.c:5531 __flush_work+0x105/0xa90 kernel/workqueue.c:3053 hci_dev_do_close+0x131/0x1240 net/bluetooth/hci_core.c:1745 hci_rfkill_set_block+0x166/0x1a0 net/bluetooth/hci_core.c:2223 rfkill_set_block+0x1fd/0x540 net/rfkill/core.c:341 rfkill_fop_write+0x253/0x4b0 net/rfkill/core.c:1240 vfs_write+0x29a/0xa70 fs/read_write.c:603 ksys_write+0x1f6/0x260 fs/read_write.c:658 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x62/0xc7 RIP: 0033:0x7fbe2d7b4b19 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fbe2ad09188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fbe2d8c8020 RCX: 00007fbe2d7b4b19 device veth0_vlan entered promiscuous mode RDX: 0000000000000008 RSI: 00000000200000c0 RDI: 0000000000000006 RBP: 00007fbe2d80ef6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe395eb77f R14: 00007fbe2ad09300 R15: 0000000000022000 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 1 PID: 7050 Comm: syz-executor.5 Not tainted 5.10.207 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x107/0x167 lib/dump_stack.c:118 fail_dump lib/fault-inject.c:52 [inline] should_fail.cold+0x5/0xa lib/fault-inject.c:146 should_failslab+0x5/0x20 mm/slab_common.c:1193 slab_pre_alloc_hook mm/slab.h:515 [inline] slab_alloc_node mm/slub.c:2821 [inline] kmem_cache_alloc_node+0x55/0x330 mm/slub.c:2932 __alloc_skb+0x6d/0x5b0 net/core/skbuff.c:198 alloc_skb include/linux/skbuff.h:1102 [inline] alloc_skb_with_frags+0x92/0x570 net/core/skbuff.c:5907 sock_alloc_send_pskb+0x7af/0x930 net/core/sock.c:2363 unix_dgram_sendmsg+0x3d6/0x1a10 net/unix/af_unix.c:1740 sock_sendmsg_nosec net/socket.c:651 [inline] __sock_sendmsg net/socket.c:663 [inline] sock_sendmsg+0x2af/0x310 net/socket.c:685 sock_no_sendpage+0x12c/0x1a0 net/core/sock.c:2867 kernel_sendpage.part.0+0x146/0x290 net/socket.c:3546 kernel_sendpage net/socket.c:3543 [inline] sock_sendpage+0xe5/0x140 net/socket.c:961 pipe_to_sendpage+0x2af/0x380 fs/splice.c:364 splice_from_pipe_feed fs/splice.c:418 [inline] __splice_from_pipe+0x43d/0x890 fs/splice.c:562 splice_from_pipe fs/splice.c:597 [inline] generic_splice_sendpage+0xd5/0x140 fs/splice.c:743 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0x10f/0x170 fs/splice.c:933 splice_direct_to_actor+0x387/0x980 fs/splice.c:888 do_splice_direct+0x1c4/0x290 fs/splice.c:976 do_sendfile+0x553/0x1090 fs/read_write.c:1257 __do_sys_sendfile64 fs/read_write.c:1318 [inline] __se_sys_sendfile64 fs/read_write.c:1304 [inline] __x64_sys_sendfile64+0x1d1/0x210 fs/read_write.c:1304 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x62/0xc7 RIP: 0033:0x7f2ae505db19 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2ae25d3188 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f2ae5170f60 RCX: 00007f2ae505db19 RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000004 RBP: 00007f2ae25d31d0 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000b052 R11: 0000000000000246 R12: 0000000000000002 R13: 00007fff580a8eaf R14: 00007f2ae25d3300 R15: 0000000000022000 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 1 PID: 7049 Comm: syz-executor.1 Not tainted 5.10.207 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x107/0x167 lib/dump_stack.c:118 fail_dump lib/fault-inject.c:52 [inline] should_fail.cold+0x5/0xa lib/fault-inject.c:146 should_failslab+0x5/0x20 mm/slab_common.c:1193 slab_pre_alloc_hook mm/slab.h:515 [inline] slab_alloc_node mm/slub.c:2821 [inline] slab_alloc mm/slub.c:2904 [inline] kmem_cache_alloc+0x5b/0x310 mm/slub.c:2909 mem_pool_alloc mm/kmemleak.c:423 [inline] create_object.isra.0+0x3a/0xa20 mm/kmemleak.c:578 kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline] slab_post_alloc_hook mm/slab.h:534 [inline] slab_alloc_node mm/slub.c:2896 [inline] __kmalloc_node+0x1ae/0x420 mm/slub.c:4015 kmalloc_node include/linux/slab.h:575 [inline] kvmalloc_node+0xc0/0x170 mm/util.c:607 kvmalloc include/linux/mm.h:765 [inline] kvmalloc_array include/linux/mm.h:783 [inline] __ptr_ring_init_queue_alloc include/linux/ptr_ring.h:471 [inline] ptr_ring_init include/linux/ptr_ring.h:489 [inline] skb_array_init include/linux/skb_array.h:182 [inline] pfifo_fast_init+0xea/0x3d0 net/sched/sch_generic.c:779 qdisc_create_dflt+0x103/0x370 net/sched/sch_generic.c:931 attach_one_default_qdisc net/sched/sch_generic.c:1087 [inline] netdev_for_each_tx_queue include/linux/netdevice.h:2286 [inline] attach_default_qdiscs net/sched/sch_generic.c:1105 [inline] dev_activate+0x7c3/0xd70 net/sched/sch_generic.c:1164 __dev_open+0x38a/0x4e0 net/core/dev.c:1544 __dev_change_flags+0x521/0x6e0 net/core/dev.c:8507 dev_change_flags+0x8a/0x160 net/core/dev.c:8578 devinet_ioctl+0x14de/0x1db0 net/ipv4/devinet.c:1143 inet_ioctl+0x34f/0x390 net/ipv4/af_inet.c:969 packet_ioctl+0xb3/0x260 net/packet/af_packet.c:4206 sock_do_ioctl+0xd3/0x300 net/socket.c:1064 sock_ioctl+0x3ea/0x700 net/socket.c:1204 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x19a/0x210 fs/ioctl.c:739 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x62/0xc7 RIP: 0033:0x7f86bc084b19 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f86b95fa188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f86bc197f60 RCX: 00007f86bc084b19 RDX: 00000000200001c0 RSI: 0000000000008914 RDI: 0000000000000004 RBP: 00007f86b95fa1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffe4669ad8f R14: 00007f86b95fa300 R15: 0000000000022000 device veth0_vlan entered promiscuous mode ieee802154 phy0 wpan0: encryption failed: -22 ieee802154 phy0 wpan0: encryption failed: -22 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: ff c3 inc %ebx 2: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1) 9: 00 00 00 c: 0f 1f 40 00 nopl 0x0(%rax) 10: 48 89 f8 mov %rdi,%rax 13: 48 89 f7 mov %rsi,%rdi 16: 48 89 d6 mov %rdx,%rsi 19: 48 89 ca mov %rcx,%rdx 1c: 4d 89 c2 mov %r8,%r10 1f: 4d 89 c8 mov %r9,%r8 22: 4c 8b 4c 24 08 mov 0x8(%rsp),%r9 27: 0f 05 syscall * 29: 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax <-- trapping instruction 2f: 73 01 jae 0x32 31: c3 retq 32: 48 c7 c1 bc ff ff ff mov $0xffffffffffffffbc,%rcx 39: f7 d8 neg %eax 3b: 64 89 01 mov %eax,%fs:(%rcx) 3e: 48 rex.W