KCSAN: data-race in copy_mm / copy_page

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in copy_mm / copy_page_range mm	6				3	142d	197d	0/29	auto-obsoleted due to no activity on 2025/08/17 07:05
upstream	KCSAN: data-race in copy_mm / copy_page_range (2) mm	6				1	64d	64d	0/29	auto-obsoleted due to no activity on 2025/11/03 02:56

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BUG: KCSAN: data-race in copy_mm / copy_page_range

read-write to 0xffff88810cb99e60 of 4 bytes by task 17026 on cpu 0:
 do_raw_write_seqcount_begin include/linux/seqlock.h:431 [inline]
 copy_page_range+0x25e/0x3be0 mm/memory.c:1528
 dup_mmap+0x885/0xf20 mm/mmap.c:1834
 dup_mm kernel/fork.c:1489 [inline]
 copy_mm+0x11a/0x370 kernel/fork.c:1541
 copy_process+0xd08/0x2000 kernel/fork.c:2181
 kernel_clone+0x16c/0x5c0 kernel/fork.c:2609
 __do_sys_clone kernel/fork.c:2750 [inline]
 __se_sys_clone kernel/fork.c:2734 [inline]
 __x64_sys_clone+0xe6/0x120 kernel/fork.c:2734
 x64_sys_call+0x119c/0x3000 arch/x86/include/generated/asm/syscalls_64.h:57
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88810cb99cc0 of 1408 bytes by task 17027 on cpu 1:
 dup_mm kernel/fork.c:1483 [inline]
 copy_mm+0xe2/0x370 kernel/fork.c:1541
 copy_process+0xd08/0x2000 kernel/fork.c:2181
 kernel_clone+0x16c/0x5c0 kernel/fork.c:2609
 __do_sys_clone kernel/fork.c:2750 [inline]
 __se_sys_clone kernel/fork.c:2734 [inline]
 __x64_sys_clone+0xe6/0x120 kernel/fork.c:2734
 x64_sys_call+0x119c/0x3000 arch/x86/include/generated/asm/syscalls_64.h:57
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 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: 17027 Comm: syz.0.4534 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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