ci2 starts bisection 2025-12-18 15:29:50.586271059 +0000 UTC m=+1908002.763394117
bisecting fixing commit since 145c7fad733f13d7a8f4aa156785f40d38e966da
building syzkaller on 44f8051e446824395d02720c745353cd454d9553
ensuring issue is reproducible on original commit 145c7fad733f13d7a8f4aa156785f40d38e966da
testing commit 145c7fad733f13d7a8f4aa156785f40d38e966da gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: 5bdb9c146fc400507195b45cfef1a1ddc058053c727ecc8027fba6522174fdbb
run #0: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #1: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #2: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #3: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #4: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #5: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #6: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #7: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #8: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #9: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #10: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #11: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #18: OK
run #19: OK
representative crash: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread, types: [KASAN-NULL-POINTER-DEREFERENCE-WRITE]
check whether we can drop unnecessary instrumentation
disabling configs for [atomic_sleep hang memleak ubsan bug_or_warning locking], they are not needed
testing commit 145c7fad733f13d7a8f4aa156785f40d38e966da gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: 9980d35ed10d866a261c1995761ada01d4d6c17de6a53a42fde489b835002aca
run #0: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #1: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #2: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #3: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #4: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #5: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #6: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #7: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #8: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #9: OK
representative crash: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread, types: [KASAN-NULL-POINTER-DEREFERENCE-WRITE]
the bug reproduces without the instrumentation
disabling configs for [ubsan bug_or_warning locking atomic_sleep hang memleak], they are not needed
kconfig minimization: base=5186 full=6555 leaves diff=264
split chunks (needed=false): <264>
split chunk #0 of len 264 into 5 parts
testing without sub-chunk 1/5
disabling configs for [hang memleak ubsan bug_or_warning locking atomic_sleep], they are not needed
testing commit 145c7fad733f13d7a8f4aa156785f40d38e966da gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: 67f9a172c51bb25fb9c60982e18e426523f942d9da8785a8ab67918fe6133b2f
run #0: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #1: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #2: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #3: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #4: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #5: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #6: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #7: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #8: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #9: OK
representative crash: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread, types: [KASAN-NULL-POINTER-DEREFERENCE-WRITE]
the chunk can be dropped
testing without sub-chunk 2/5
disabling configs for [ubsan bug_or_warning locking atomic_sleep hang memleak], they are not needed
testing commit 145c7fad733f13d7a8f4aa156785f40d38e966da gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: 4e9e2042064564badd732d45440599ab478ddffbd379557bc62e67081edc0977
run #0: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #1: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #2: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #3: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #4: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #5: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #6: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #7: OK
run #8: OK
run #9: OK
representative crash: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread, types: [KASAN-NULL-POINTER-DEREFERENCE-WRITE]
the chunk can be dropped
testing without sub-chunk 3/5
disabling configs for [atomic_sleep hang memleak ubsan bug_or_warning locking], they are not needed
testing commit 145c7fad733f13d7a8f4aa156785f40d38e966da gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: 2c0ed8d4fd75ce7d8df4de5410cfa1f270d909be604bd4d520f7b202215e36f5
run #0: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #1: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #2: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #3: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #4: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #5: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #6: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #7: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #8: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #9: OK
representative crash: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread, types: [KASAN-NULL-POINTER-DEREFERENCE-WRITE]
the chunk can be dropped
testing without sub-chunk 4/5
disabling configs for [memleak ubsan bug_or_warning locking atomic_sleep hang], they are not needed
testing commit 145c7fad733f13d7a8f4aa156785f40d38e966da gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: 02a608c4cc419f23d2963c0009b5e6624754cb028281ab89e057869ef8279c8b
run #0: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #1: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #2: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #3: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #4: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #5: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #6: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #7: OK
run #8: OK
run #9: OK
representative crash: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread, types: [KASAN-NULL-POINTER-DEREFERENCE-WRITE]
the chunk can be dropped
testing without sub-chunk 5/5
disabling configs for [locking atomic_sleep hang memleak ubsan bug_or_warning], they are not needed
testing commit 145c7fad733f13d7a8f4aa156785f40d38e966da gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
failed building 145c7fad733f13d7a8f4aa156785f40d38e966da: ld.lld: error: undefined symbol: wext_proc_init
ld.lld: error: undefined symbol: wext_proc_exit
ld.lld: error: undefined symbol: wext_handle_ioctl
ld.lld: error: undefined symbol: compat_wext_handle_ioctl
minimized to 52 configs; suspects: [HID_ZEROPLUS USB_NET_CDC_MBIM USB_NET_CDC_SUBSET USB_NET_CDC_SUBSET_ENABLE USB_NET_DM9601 USB_NET_GL620A USB_NET_MCS7830 USB_NET_NET1080 USB_NET_PLUSB USB_NET_RNDIS_HOST USB_NET_SMSC75XX USB_NET_SMSC95XX USB_NET_SR9700 USB_NET_SR9800 USB_NET_ZAURUS USB_OHCI_HCD USB_OHCI_HCD_PCI USB_OHCI_HCD_PLATFORM USB_OTG USB_OTG_FSM USB_PRINTER USB_SERIAL_GENERIC USB_SERIAL_PL2303 USB_STORAGE_ALAUDA USB_STORAGE_CYPRESS_ATACB USB_STORAGE_DATAFAB USB_STORAGE_FREECOM USB_STORAGE_ISD200 USB_STORAGE_JUMPSHOT USB_STORAGE_KARMA USB_STORAGE_ONETOUCH USB_STORAGE_SDDR09 USB_STORAGE_SDDR55 USB_STORAGE_USBAT USB_TRANCEVIBRATOR USB_U_AUDIO USB_U_ETHER USB_U_SERIAL USB_WDM V4L2_ASYNC V4L2_FWNODE VIDEO_CAMERA_SENSOR WLAN WLAN_VENDOR_ATH WLAN_VENDOR_ATMEL WLAN_VENDOR_BROADCOM WLAN_VENDOR_INTERSIL WLAN_VENDOR_MARVELL WLAN_VENDOR_MEDIATEK WLAN_VENDOR_MICROCHIP WLAN_VENDOR_PURELIFI WLAN_VENDOR_RALINK WLAN_VENDOR_REALTEK WLAN_VENDOR_RSI WLAN_VENDOR_SILABS WLAN_VENDOR_ZYDAS ZEROPLUS_FF]
disabling configs for [memleak ubsan bug_or_warning locking atomic_sleep hang], they are not needed
testing current HEAD 72ada78f601d704f44161ace443aa7cd03c257a7
testing commit 72ada78f601d704f44161ace443aa7cd03c257a7 gcc
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
kernel signature: 4d9569f49280a16179221e3a642ad1b6e182fe1431dc3f3d194d1d821c2cc599
run #0: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #1: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #2: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #3: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #4: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #5: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #6: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #7: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #8: crashed: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
run #9: OK
representative crash: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread, types: [KASAN-NULL-POINTER-DEREFERENCE-WRITE]
crash still not fixed/happens on the oldest tested release
revisions tested: 7, total time: 2h10m19.822134362s (build: 26m34.725005549s, test: 1h37m46.048896044s)
crash still not fixed or there were kernel test errors
commit msg: Merge tag 'android14-6.1.158_r00' into android14-6.1
crash: KASAN: null-ptr-deref Write in f2fs_stop_gc_thread
==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
BUG: KASAN: null-ptr-deref in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:116 [inline]
BUG: KASAN: null-ptr-deref in __refcount_add include/linux/refcount.h:193 [inline]
BUG: KASAN: null-ptr-deref in __refcount_inc include/linux/refcount.h:250 [inline]
BUG: KASAN: null-ptr-deref in refcount_inc include/linux/refcount.h:267 [inline]
BUG: KASAN: null-ptr-deref in get_task_struct include/linux/sched/task.h:110 [inline]
BUG: KASAN: null-ptr-deref in kthread_stop+0x2e/0x270 kernel/kthread.c:717
Write of size 4 at addr 0000000000000028 by task syz.6.151/1323
CPU: 0 PID: 1323 Comm: syz.6.151 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
__dump_stack+0x19/0x1c lib/dump_stack.c:88
dump_stack_lvl+0xa3/0xec lib/dump_stack.c:106
print_report+0x3d/0x60 mm/kasan/report.c:423
kasan_report+0x122/0x150 mm/kasan/report.c:524
check_region_inline mm/kasan/generic.c:-1 [inline]
kasan_check_range+0x280/0x290 mm/kasan/generic.c:189
__kasan_check_write+0x14/0x20 mm/kasan/shadow.c:37
instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:116 [inline]
__refcount_add include/linux/refcount.h:193 [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:110 [inline]
kthread_stop+0x2e/0x270 kernel/kthread.c:717
f2fs_stop_gc_thread+0x5b/0xa0 fs/f2fs/gc.c:210
f2fs_ioc_shutdown fs/f2fs/file.c:2402 [inline]
__f2fs_ioctl+0x4e62/0xa040 fs/f2fs/file.c:4385
f2fs_ioctl+0x11d/0x1e0 fs/f2fs/file.c:4466
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xc5/0x110 fs/ioctl.c:856
__x64_sys_ioctl+0x76/0x80 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:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f9bfc78e929
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:00007f9bfd54c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f9bfc9b6080 RCX: 00007f9bfc78e929
RDX: 0000200000000140 RSI: 000000008004587d RDI: 0000000000000005
RBP: 00007f9bfc810ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f9bfc9b6080 R15: 00007ffda0c3dba8
==================================================================
BUG: kernel NULL pointer dereference, address: 0000000000000028
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 12049e067 P4D 12049e067 PUD 0
Oops: 0002 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 1323 Comm: syz.6.151 Tainted: G B syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:arch_atomic_fetch_add arch/x86/include/asm/atomic.h:184 [inline]
RIP: 0010:atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:117 [inline]
RIP: 0010:__refcount_add include/linux/refcount.h:193 [inline]
RIP: 0010:__refcount_inc include/linux/refcount.h:250 [inline]
RIP: 0010:refcount_inc include/linux/refcount.h:267 [inline]
RIP: 0010:get_task_struct include/linux/sched/task.h:110 [inline]
RIP: 0010:kthread_stop+0x38/0x270 kernel/kthread.c:717
Code: 49 bc 00 00 00 00 00 fc ff df 0f 1f 44 00 00 4c 8d 73 28 4c 89 f7 be 04 00 00 00 e8 a2 1a 5c 00 be 01 00 00 00 b8 01 00 00 00 0f c1 43 28 85 c0 0f 84 b9 00 00 00 3d ff ff ff 7f 0f 83 b3 00
RSP: 0018:ffffc90002c778e0 EFLAGS: 00010246
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff8138b663
RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffffffff85cb57e0
RBP: ffffc90002c77900 R08: dffffc0000000000 R09: fffffbfff0b96afd
R10: fffffbfff0b96afd R11: 1ffffffff0b96afc R12: dffffc0000000000
R13: ffff8881185a0000 R14: 0000000000000028 R15: dffffc0000000000
FS: 00007f9bfd54c6c0(0000) GS:ffff8881f7300000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000028 CR3: 000000010cf17000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
f2fs_stop_gc_thread+0x5b/0xa0 fs/f2fs/gc.c:210
f2fs_ioc_shutdown fs/f2fs/file.c:2402 [inline]
__f2fs_ioctl+0x4e62/0xa040 fs/f2fs/file.c:4385
f2fs_ioctl+0x11d/0x1e0 fs/f2fs/file.c:4466
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xc5/0x110 fs/ioctl.c:856
__x64_sys_ioctl+0x76/0x80 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:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f9bfc78e929
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:00007f9bfd54c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f9bfc9b6080 RCX: 00007f9bfc78e929
RDX: 0000200000000140 RSI: 000000008004587d RDI: 0000000000000005
RBP: 00007f9bfc810ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f9bfc9b6080 R15: 00007ffda0c3dba8
Modules linked in:
CR2: 0000000000000028
---[ end trace 0000000000000000 ]---
RIP: 0010:arch_atomic_fetch_add arch/x86/include/asm/atomic.h:184 [inline]
RIP: 0010:atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:117 [inline]
RIP: 0010:__refcount_add include/linux/refcount.h:193 [inline]
RIP: 0010:__refcount_inc include/linux/refcount.h:250 [inline]
RIP: 0010:refcount_inc include/linux/refcount.h:267 [inline]
RIP: 0010:get_task_struct include/linux/sched/task.h:110 [inline]
RIP: 0010:kthread_stop+0x38/0x270 kernel/kthread.c:717
Code: 49 bc 00 00 00 00 00 fc ff df 0f 1f 44 00 00 4c 8d 73 28 4c 89 f7 be 04 00 00 00 e8 a2 1a 5c 00 be 01 00 00 00 b8 01 00 00 00 0f c1 43 28 85 c0 0f 84 b9 00 00 00 3d ff ff ff 7f 0f 83 b3 00
RSP: 0018:ffffc90002c778e0 EFLAGS: 00010246
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff8138b663
RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffffffff85cb57e0
RBP: ffffc90002c77900 R08: dffffc0000000000 R09: fffffbfff0b96afd
R10: fffffbfff0b96afd R11: 1ffffffff0b96afc R12: dffffc0000000000
R13: ffff8881185a0000 R14: 0000000000000028 R15: dffffc0000000000
FS: 00007f9bfd54c6c0(0000) GS:ffff8881f7300000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000028 CR3: 000000010cf17000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 49 bc 00 00 00 00 00 movabs $0xdffffc0000000000,%r12
7: fc ff df
a: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
f: 4c 8d 73 28 lea 0x28(%rbx),%r14
13: 4c 89 f7 mov %r14,%rdi
16: be 04 00 00 00 mov $0x4,%esi
1b: e8 a2 1a 5c 00 call 0x5c1ac2
20: be 01 00 00 00 mov $0x1,%esi
25: b8 01 00 00 00 mov $0x1,%eax
* 2a: f0 0f c1 43 28 lock xadd %eax,0x28(%rbx) <-- trapping instruction
2f: 85 c0 test %eax,%eax
31: 0f 84 b9 00 00 00 je 0xf0
37: 3d ff ff ff 7f cmp $0x7fffffff,%eax
3c: 0f .byte 0xf
3d: 83 .byte 0x83
3e: b3 00 mov $0x0,%bl