KCSAN: data-race in futex_hash_allocate / futex_hash

ID	Workflow	Result	Correct	Bug	Created	Started	Finished	Revision	Error
b18fd553-ae7c-443c-a970-84912b0e0b16	assessment-kcsan	Benign: ✅ Confident: ✅	❓	KCSAN: data-race in futex_hash_allocate / futex_hash_allocate (3)	2026/02/24 18:20	2026/02/24 18:20	2026/02/24 18:29	305c0ec5cd886e2d13738e28e1b2df9b0ec20fc9
0c497ce0-49eb-415e-9e55-8a5fe1f96655	assessment-kcsan		🏃	KCSAN: data-race in futex_hash_allocate / futex_hash_allocate (3)	2026/02/12 16:24	2026/02/13 12:52		3f45136dc7eb71e0f74e923b9f5ca8ecd555f59a

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in futex_hash_allocate / futex_hash_allocate kernel	6				1	199d	199d	0/29	auto-obsoleted due to no activity on 2025/10/11 04:10
upstream	KCSAN: data-race in futex_hash_allocate / futex_hash_allocate (2) kernel	6				1	140d	140d	0/29	auto-obsoleted due to no activity on 2025/12/09 12:22

Kernel

Title

Rank 🛈

upstream

KCSAN: data-race in futex_hash_allocate / futex_hash_allocate kernel

199d

0/29

auto-obsoleted due to no activity on 2025/10/11 04:10

upstream

KCSAN: data-race in futex_hash_allocate / futex_hash_allocate (2) kernel

140d

0/29

auto-obsoleted due to no activity on 2025/12/09 12:22

================================================================== BUG: KCSAN: data-race in futex_hash_allocate / futex_hash_allocate read-write to 0xffff88810c5a74c0 of 8 bytes by task 12336 on cpu 0: futex_hash_allocate+0x673/0x9d0 kernel/futex/core.c:1839 futex_hash_prctl+0xd8/0xf0 kernel/futex/core.c:1958 __do_sys_prctl kernel/sys.c:2870 [inline] __se_sys_prctl+0x914/0x1320 kernel/sys.c:2519 __x64_sys_prctl+0x67/0x80 kernel/sys.c:2519 x64_sys_call+0x2533/0x3020 arch/x86/include/generated/asm/syscalls_64.h:158 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff88810c5a74c0 of 8 bytes by task 12335 on cpu 1: futex_pivot_pending kernel/futex/core.c:1748 [inline] futex_hash_allocate+0x5fa/0x9d0 kernel/futex/core.c:1829 futex_hash_prctl+0xd8/0xf0 kernel/futex/core.c:1958 __do_sys_prctl kernel/sys.c:2870 [inline] __se_sys_prctl+0x914/0x1320 kernel/sys.c:2519 __x64_sys_prctl+0x67/0x80 kernel/sys.c:2519 x64_sys_call+0x2533/0x3020 arch/x86/include/generated/asm/syscalls_64.h:158 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0xffff88811bf79cc0 -> 0x0000000000000000 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 12335 Comm: syz.8.2051 Tainted: G W syzkaller #0 PREEMPT(full) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 ==================================================================

Crashes (1):
Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Assets (help?)	Manager	Title
2026/02/11 09:45	upstream	dc855b77719f	441e25b7	.config	console log	report			info	[disk image] [vmlinux] [kernel image]	ci2-upstream-kcsan-gce	KCSAN: data-race in futex_hash_allocate / futex_hash_allocate

Crashes (1):

Assets (help?)