KCSAN: data-race in __mmput / copy

ID	Workflow	Result	Correct	Bug	Created	Started	Finished	Revision	Error
751f4600-6dec-4296-a675-8d10b6054911	assessment-security	DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌	❓	KCSAN: data-race in __mmput / copy_mm (3)	2026/05/21 07:10	2026/05/21 07:10	2026/05/21 07:53	cf874a1cf36318c06202027159ddac14acf00db7
4525cc73-aa85-4ce8-bae8-ecf6761d52e2	assessment-kcsan	Benign: ✅	❓	KCSAN: data-race in __mmput / copy_mm (3)	2026/05/08 14:18	2026/05/08 14:18	2026/05/08 14:40	04e3cfe80d8d1595bcb750e55868b0ba3c416767

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in __mmput / copy_mm (2) kernel	6				1	121d	121d	0/29	auto-obsoleted due to no activity on 2026/03/24 11:25
upstream	KCSAN: data-race in __mmput / copy_mm mm	6				1	344d	344d	0/29	auto-obsoleted due to no activity on 2025/08/12 22:58

Kernel

Title

Rank 🛈

upstream

KCSAN: data-race in __mmput / copy_mm (2) kernel

121d

0/29

auto-obsoleted due to no activity on 2026/03/24 11:25

upstream

KCSAN: data-race in __mmput / copy_mm mm

344d

0/29

auto-obsoleted due to no activity on 2025/08/12 22:58

================================================================== BUG: KCSAN: data-race in __mmput / copy_mm write to 0xffff888103c5e6f8 of 8 bytes by task 20512 on cpu 0: __list_del include/linux/list.h:203 [inline] __list_del_entry include/linux/list.h:226 [inline] list_del include/linux/list.h:237 [inline] __mmput+0xe2/0x1c0 kernel/fork.c:1183 mmput+0x40/0x50 kernel/fork.c:1201 exit_mm+0x113/0x1a0 kernel/exit.c:581 do_exit+0x442/0x1530 kernel/exit.c:963 do_group_exit+0x138/0x140 kernel/exit.c:1117 __do_sys_exit_group kernel/exit.c:1128 [inline] __se_sys_exit_group kernel/exit.c:1126 [inline] __x64_sys_exit_group+0x1f/0x20 kernel/exit.c:1126 x64_sys_call+0x3008/0x3020 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff888103c5e540 of 1664 bytes by task 3308 on cpu 1: dup_mm kernel/fork.c:1528 [inline] copy_mm+0xe1/0x370 kernel/fork.c:1586 copy_process+0x1087/0x2370 kernel/fork.c:2264 kernel_clone+0x1a5/0x5e0 kernel/fork.c:2721 __do_sys_clone kernel/fork.c:2862 [inline] __se_sys_clone kernel/fork.c:2846 [inline] __x64_sys_clone+0x143/0x180 kernel/fork.c:2846 x64_sys_call+0x1222/0x3020 arch/x86/include/generated/asm/syscalls_64.h:57 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 3308 Comm: syz-executor Tainted: G W syzkaller #0 PREEMPT(full) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 ==================================================================

Crashes (1):
Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Assets (help?)	Manager	Title
2026/05/08 14:18	upstream	917719c412c4	b2988c17	.config	console log	report			info	[disk image] [vmlinux] [kernel image]	ci2-upstream-kcsan-gce	KCSAN: data-race in __mmput / copy_mm

Crashes (1):

Assets (help?)