[moderation] [lsm?] KCSAN: data-race in copy_creds / prepare_creds (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 502d801f0ab0 Merge tag 'erofs-for-7.2-rc1' of git://git.ke..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12ad501c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=4d0f6c16a80c07db
dashboard link: https://syzkaller.appspot.com/bug?extid=5227aabe7c8960628bea
compiler: Debian clang version 22.1.6 (++20260514074242+fc4aad7b5db3-1~exp1~20260514074407.73), Debian LLD 22.1.6
CC: [linux-...@vger.kernel.org linux-secu...@vger.kernel.org pa...@paul-moore.com ser...@kernel.org]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7a2ab34be1f7/disk-502d801f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/344e858ce175/vmlinux-502d801f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/269d734808e7/bzImage-502d801f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5227aa...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in copy_creds / prepare_creds

write to 0xffff888103fc6b28 of 4 bytes by task 9782 on cpu 0:
get_cred_many include/linux/cred.h:222 [inline]
copy_creds+0x78/0x340 kernel/cred.c:278
copy_process+0x8b8/0x2350 kernel/fork.c:2148
kernel_clone+0x1c0/0x5f0 kernel/fork.c:2746
__do_sys_clone3 kernel/fork.c:3048 [inline]
__se_sys_clone3+0x1f5/0x230 kernel/fork.c:3027
__x64_sys_clone3+0x31/0x40 kernel/fork.c:3027
x64_sys_call+0x580/0x3020 arch/x86/include/generated/asm/syscalls_64.h:436
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888103fc6a80 of 184 bytes by task 9783 on cpu 1:
prepare_creds+0x71/0x550 kernel/cred.c:192
__do_sys_capset kernel/capability.c:247 [inline]
__se_sys_capset+0x2da/0x480 kernel/capability.c:216
__x64_sys_capset+0x31/0x40 kernel/capability.c:216
x64_sys_call+0x2aac/0x3020 arch/x86/include/generated/asm/syscalls_64.h:127
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x136/0x3c0 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: 9783 Comm: syz.5.1734 Tainted: G W syzkaller #0 PREEMPT(lazy)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
==================================================================


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