================================================================== BUG: KASAN: use-after-free in f2fs_stop_gc_thread+0x5d/0xb0 fs/f2fs/gc.c:199 Read of size 8 at addr ffff888105fecd00 by task syz.4.2419/10480 CPU: 1 PID: 10480 Comm: syz.4.2419 Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x169/0x1d8 lib/dump_stack.c:118 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0xe2/0x130 mm/kasan/report.c:452 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309 f2fs_stop_gc_thread+0x5d/0xb0 fs/f2fs/gc.c:199 f2fs_ioc_shutdown fs/f2fs/file.c:2374 [inline] __f2fs_ioctl+0x6f1b/0xca50 fs/f2fs/file.c:4343 f2fs_ioctl+0x149/0x240 fs/f2fs/file.c:4428 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0x121/0x1a0 fs/ioctl.c:739 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:739 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7ff64802afc9 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff646a93038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ff648281fa0 RCX: 00007ff64802afc9 RDX: 0000200000000080 RSI: 000000008004587d RDI: 0000000000000010 RBP: 00007ff6480adf91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff648282038 R14: 00007ff648281fa0 R15: 00007fff61f010c8 Allocated by task 10484: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:430 [inline] ____kasan_kmalloc mm/kasan/common.c:509 [inline] __kasan_kmalloc+0xda/0x110 mm/kasan/common.c:518 kasan_kmalloc include/linux/kasan.h:254 [inline] kmem_cache_alloc_trace+0x184/0x2e0 mm/slub.c:2979 kmalloc include/linux/slab.h:552 [inline] f2fs_kmalloc fs/f2fs/f2fs.h:3357 [inline] f2fs_start_gc_thread+0xa3/0x380 fs/f2fs/gc.c:166 f2fs_fill_super+0x5ef3/0x6c70 fs/f2fs/super.c:4478 mount_bdev+0x28b/0x3a0 fs/super.c:1442 f2fs_mount+0x34/0x40 fs/f2fs/super.c:4595 legacy_get_tree+0xed/0x190 fs/fs_context.c:593 vfs_get_tree+0x89/0x260 fs/super.c:1572 do_new_mount+0x25a/0xa20 fs/namespace.c:2997 path_mount+0x572/0xc80 fs/namespace.c:3327 do_mount fs/namespace.c:3340 [inline] __do_sys_mount fs/namespace.c:3548 [inline] __se_sys_mount+0x318/0x380 fs/namespace.c:3525 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3525 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 10484: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4a/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:362 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370 kasan_slab_free include/linux/kasan.h:220 [inline] slab_free_hook mm/slub.c:1600 [inline] slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1626 slab_free mm/slub.c:3208 [inline] kfree+0xc0/0x270 mm/slub.c:4196 f2fs_stop_gc_thread+0x7f/0xb0 fs/f2fs/gc.c:201 f2fs_ioc_shutdown fs/f2fs/file.c:2374 [inline] __f2fs_ioctl+0x6f1b/0xca50 fs/f2fs/file.c:4343 f2fs_ioctl+0x149/0x240 fs/f2fs/file.c:4428 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0x121/0x1a0 fs/ioctl.c:739 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:739 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358 __call_rcu kernel/rcu/tree.c:2980 [inline] call_rcu+0x10e/0x1050 kernel/rcu/tree.c:3054 tnode_free net/ipv4/fib_trie.c:495 [inline] replace+0x1a1/0x450 net/ipv4/fib_trie.c:521 inflate net/ipv4/fib_trie.c:623 [inline] resize+0x10ec/0x2450 net/ipv4/fib_trie.c:868 trie_rebalance net/ipv4/fib_trie.c:1059 [inline] fib_insert_node net/ipv4/fib_trie.c:1103 [inline] fib_insert_alias+0x98f/0x1020 net/ipv4/fib_trie.c:1117 fib_table_insert+0x6d5/0x1bb0 net/ipv4/fib_trie.c:1309 fib_magic net/ipv4/fib_frontend.c:1107 [inline] fib_add_ifaddr+0x31b/0xed0 net/ipv4/fib_frontend.c:1129 fib_inetaddr_event+0x15d/0x310 net/ipv4/fib_frontend.c:1445 notifier_call_chain kernel/notifier.c:83 [inline] blocking_notifier_call_chain+0xba/0x140 kernel/notifier.c:337 __inet_insert_ifa+0x87e/0xa70 net/ipv4/devinet.c:567 inet_rtm_newaddr+0xc34/0x1510 net/ipv4/devinet.c:967 rtnetlink_rcv_msg+0x9db/0xb90 net/core/rtnetlink.c:5610 netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2503 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5628 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x876/0xa40 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x88d/0xb30 net/netlink/af_netlink.c:1914 sock_sendmsg_nosec net/socket.c:652 [inline] __sock_sendmsg net/socket.c:664 [inline] __sys_sendto+0x41d/0x580 net/socket.c:2006 __do_sys_sendto net/socket.c:2018 [inline] __se_sys_sendto net/socket.c:2014 [inline] __x64_sys_sendto+0xe5/0x100 net/socket.c:2014 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff888105fecd00 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 0 bytes inside of 96-byte region [ffff888105fecd00, ffff888105fecd60) The buggy address belongs to the page: page:ffffea000417fb00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x105fec flags: 0x4000000000000200(slab) raw: 4000000000000200 ffffea00047649c0 0000000a0000000a ffff888100043680 raw: 0000000000000000 0000000000200020 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 1, ts 1613890225, free_ts 0 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x179/0x180 mm/page_alloc.c:2462 get_page_from_freelist+0x2235/0x23d0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x268/0x5f0 mm/page_alloc.c:5370 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1813 [inline] new_slab+0x84/0x3f0 mm/slub.c:1874 new_slab_objects mm/slub.c:2632 [inline] ___slab_alloc+0x2a6/0x450 mm/slub.c:2796 __slab_alloc+0x63/0xa0 mm/slub.c:2836 slab_alloc_node mm/slub.c:2918 [inline] slab_alloc mm/slub.c:2960 [inline] kmem_cache_alloc_trace+0x1b3/0x2e0 mm/slub.c:2977 kmalloc include/linux/slab.h:552 [inline] kzalloc include/linux/slab.h:664 [inline] acpi_os_allocate_zeroed include/acpi/platform/aclinuxex.h:57 [inline] acpi_evaluate_object+0x10b/0xa00 drivers/acpi/acpica/nsxfeval.c:177 acpi_evaluate_integer+0xf5/0x1c0 drivers/acpi/utils.c:279 acpi_find_child_device+0x115/0x5b0 drivers/acpi/glue.c:128 acpi_pci_find_companion+0xde/0x120 drivers/pci/pci-acpi.c:1171 acpi_device_notify drivers/acpi/glue.c:308 [inline] acpi_platform_notify+0x238/0x3d0 drivers/acpi/glue.c:367 device_platform_notify drivers/base/core.c:1955 [inline] device_add+0x424/0xbf0 drivers/base/core.c:3213 pci_device_add+0x11bf/0x19f0 drivers/pci/probe.c:2515 pci_scan_single_device+0x36b/0x440 drivers/pci/probe.c:2533 pci_scan_slot+0x19b/0x780 drivers/pci/probe.c:2608 page_owner free stack trace missing Memory state around the buggy address: ffff888105fecc00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888105fecc80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff888105fecd00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff888105fecd80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888105fece00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ================================================================== ------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 1 PID: 10480 at lib/refcount.c:25 refcount_warn_saturate+0x104/0x1a0 lib/refcount.c:25 Modules linked in: CPU: 1 PID: 10480 Comm: syz.4.2419 Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:refcount_warn_saturate+0x104/0x1a0 lib/refcount.c:25 Code: 04 01 48 c7 c7 e0 0e 20 85 e8 88 e5 34 02 0f 0b eb df e8 7f 3b 29 ff c6 05 7c 0a 66 04 01 48 c7 c7 20 0e 20 85 e8 6c e5 34 02 <0f> 0b eb c3 e8 63 3b 29 ff c6 05 61 0a 66 04 01 48 c7 c7 80 0e 20 RSP: 0018:ffffc90000e07878 EFLAGS: 00010246 RAX: 991a45e8f71a8a00 RBX: 0000000000000002 RCX: ffff888149fccf00 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: ffffc90000e07888 R08: dffffc0000000000 R09: fffff520001c0e41 R10: fffff520001c0e41 R11: 1ffff920001c0e40 R12: 1ffff1102093a925 R13: dffffc0000000000 R14: 0000000000000002 R15: 0000000000000000 FS: 00007ff646a936c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f411ae72000 CR3: 000000011f99a000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_add include/linux/refcount.h:-1 [inline] __refcount_inc include/linux/refcount.h:250 [inline] refcount_inc include/linux/refcount.h:267 [inline] get_task_struct include/linux/sched/task.h:108 [inline] kthread_stop+0x1b5/0x3e0 kernel/kthread.c:640 f2fs_stop_gc_thread+0x65/0xb0 fs/f2fs/gc.c:199 f2fs_ioc_shutdown fs/f2fs/file.c:2374 [inline] __f2fs_ioctl+0x6f1b/0xca50 fs/f2fs/file.c:4343 f2fs_ioctl+0x149/0x240 fs/f2fs/file.c:4428 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0x121/0x1a0 fs/ioctl.c:739 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:739 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7ff64802afc9 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff646a93038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ff648281fa0 RCX: 00007ff64802afc9 RDX: 0000200000000080 RSI: 000000008004587d RDI: 0000000000000010 RBP: 00007ff6480adf91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff648282038 R14: 00007ff648281fa0 R15: 00007fff61f010c8 ---[ end trace 2a3e6e750e0bc7c3 ]--- ------------[ cut here ]------------ WARNING: CPU: 1 PID: 10480 at kernel/kthread.c:83 to_kthread kernel/kthread.c:83 [inline] WARNING: CPU: 1 PID: 10480 at kernel/kthread.c:83 kthread_stop+0x19c/0x3e0 kernel/kthread.c:641 Modules linked in: CPU: 1 PID: 10480 Comm: syz.4.2419 Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:to_kthread kernel/kthread.c:83 [inline] RIP: 0010:kthread_stop+0x19c/0x3e0 kernel/kthread.c:641 Code: 00 0f 1f 44 00 00 e8 a3 ea 21 00 44 89 f8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 90 ea 21 00 be 02 00 00 00 eb 16 e8 84 ea 21 00 <0f> 0b e9 12 ff ff ff e8 78 ea 21 00 be 01 00 00 00 4c 89 f7 e8 fb RSP: 0018:ffffc90000e07898 EFLAGS: 00010293 RAX: ffffffff8141bb1c RBX: ffff8881242f5000 RCX: ffff888149fccf00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000e078c0 R08: dffffc0000000000 R09: fffff520001c0e41 R10: fffff520001c0e41 R11: 1ffff920001c0e40 R12: 1ffff1102093a925 R13: dffffc0000000000 R14: ffff8881242f5020 R15: 0000000000000000 FS: 00007ff646a936c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f411ae69000 CR3: 000000011f99a000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: f2fs_stop_gc_thread+0x65/0xb0 fs/f2fs/gc.c:199 f2fs_ioc_shutdown fs/f2fs/file.c:2374 [inline] __f2fs_ioctl+0x6f1b/0xca50 fs/f2fs/file.c:4343 f2fs_ioctl+0x149/0x240 fs/f2fs/file.c:4428 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0x121/0x1a0 fs/ioctl.c:739 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:739 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7ff64802afc9 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff646a93038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ff648281fa0 RCX: 00007ff64802afc9 RDX: 0000200000000080 RSI: 000000008004587d RDI: 0000000000000010 RBP: 00007ff6480adf91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff648282038 R14: 00007ff648281fa0 R15: 00007fff61f010c8 ---[ end trace 2a3e6e750e0bc7c4 ]--- BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 11211d067 P4D 11211d067 PUD 0 Oops: 0002 [#1] PREEMPT SMP KASAN CPU: 1 PID: 10480 Comm: syz.4.2419 Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:arch_set_bit include/linux/instrumented.h:86 [inline] RIP: 0010:set_bit include/asm-generic/bitops/instrumented-atomic.h:29 [inline] RIP: 0010:kthread_stop+0xe3/0x3e0 kernel/kthread.c:642 Code: 06 00 00 48 89 f8 48 c1 e8 03 42 80 3c 28 00 74 05 e8 11 db 5b 00 4c 8b bb 60 06 00 00 4c 89 ff be 08 00 00 00 e8 fd dc 5b 00 41 80 0f 02 48 89 df e8 30 fb ff ff 48 89 df e8 b8 09 02 00 49 RSP: 0018:ffffc90000e07898 EFLAGS: 00010202 RAX: 0000000000000001 RBX: ffff8881242f5000 RCX: 0000000000000286 RDX: 0000000000000001 RSI: 0000000000000008 RDI: 0000000000000000 RBP: ffffc90000e078c0 R08: 0000000000000000 R09: fffff520001c0e41 R10: fffff520001c0e41 R11: 1ffff920001c0e40 R12: 1ffff1102093a925 R13: dffffc0000000000 R14: ffff8881242f5020 R15: 0000000000000000 FS: 00007ff646a936c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000011f99a000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: f2fs_stop_gc_thread+0x65/0xb0 fs/f2fs/gc.c:199 f2fs_ioc_shutdown fs/f2fs/file.c:2374 [inline] __f2fs_ioctl+0x6f1b/0xca50 fs/f2fs/file.c:4343 f2fs_ioctl+0x149/0x240 fs/f2fs/file.c:4428 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0x121/0x1a0 fs/ioctl.c:739 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:739 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7ff64802afc9 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff646a93038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ff648281fa0 RCX: 00007ff64802afc9 RDX: 0000200000000080 RSI: 000000008004587d RDI: 0000000000000010 RBP: 00007ff6480adf91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff648282038 R14: 00007ff648281fa0 R15: 00007fff61f010c8 Modules linked in: CR2: 0000000000000000 ---[ end trace 2a3e6e750e0bc7c5 ]--- RIP: 0010:arch_set_bit include/linux/instrumented.h:86 [inline] RIP: 0010:set_bit include/asm-generic/bitops/instrumented-atomic.h:29 [inline] RIP: 0010:kthread_stop+0xe3/0x3e0 kernel/kthread.c:642 Code: 06 00 00 48 89 f8 48 c1 e8 03 42 80 3c 28 00 74 05 e8 11 db 5b 00 4c 8b bb 60 06 00 00 4c 89 ff be 08 00 00 00 e8 fd dc 5b 00 41 80 0f 02 48 89 df e8 30 fb ff ff 48 89 df e8 b8 09 02 00 49 RSP: 0018:ffffc90000e07898 EFLAGS: 00010202 RAX: 0000000000000001 RBX: ffff8881242f5000 RCX: 0000000000000286 RDX: 0000000000000001 RSI: 0000000000000008 RDI: 0000000000000000 RBP: ffffc90000e078c0 R08: 0000000000000000 R09: fffff520001c0e41 R10: fffff520001c0e41 R11: 1ffff920001c0e40 R12: 1ffff1102093a925 R13: dffffc0000000000 R14: ffff8881242f5020 R15: 0000000000000000 FS: 00007ff646a936c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000011f99a000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 00 00 add %al,(%rax) 2: 48 89 f8 mov %rdi,%rax 5: 48 c1 e8 03 shr $0x3,%rax 9: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) e: 74 05 je 0x15 10: e8 11 db 5b 00 call 0x5bdb26 15: 4c 8b bb 60 06 00 00 mov 0x660(%rbx),%r15 1c: 4c 89 ff mov %r15,%rdi 1f: be 08 00 00 00 mov $0x8,%esi 24: e8 fd dc 5b 00 call 0x5bdd26 * 29: f0 41 80 0f 02 lock orb $0x2,(%r15) <-- trapping instruction 2e: 48 89 df mov %rbx,%rdi 31: e8 30 fb ff ff call 0xfffffb66 36: 48 89 df mov %rbx,%rdi 39: e8 b8 09 02 00 call 0x209f6 3e: 49 rex.WB