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BUG: KCSAN: data-race in fifo_open / wait_for_partner

read-write to 0xffff888120fee36c of 4 bytes by task 11669 on cpu 0:
 fifo_open+0x86/0x5d0 fs/pipe.c:1132
 do_dentry_open+0x646/0xa20 fs/open.c:965
 vfs_open+0x37/0x1e0 fs/open.c:1097
 do_open fs/namei.c:3975 [inline]
 path_openat+0x1c5e/0x2170 fs/namei.c:4134
 do_filp_open+0x109/0x230 fs/namei.c:4161
 do_sys_openat2+0xa6/0x110 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_openat fs/open.c:1468 [inline]
 __se_sys_openat fs/open.c:1463 [inline]
 __x64_sys_openat+0xf2/0x120 fs/open.c:1463
 x64_sys_call+0x2eab/0x3000 arch/x86/include/generated/asm/syscalls_64.h:258
 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 0xffff888120fee36c of 4 bytes by task 11674 on cpu 1:
 pipe_unlock fs/pipe.c:97 [inline]
 wait_for_partner+0xb5/0x1c0 fs/pipe.c:1106
 fifo_open+0x4b1/0x5d0 fs/pipe.c:1197
 do_dentry_open+0x646/0xa20 fs/open.c:965
 vfs_open+0x37/0x1e0 fs/open.c:1097
 do_open fs/namei.c:3975 [inline]
 path_openat+0x1c5e/0x2170 fs/namei.c:4134
 do_filp_open+0x109/0x230 fs/namei.c:4161
 do_sys_openat2+0xa6/0x110 fs/open.c:1437
 __do_sys_openat2 fs/open.c:1495 [inline]
 __se_sys_openat2+0x194/0x1f0 fs/open.c:1471
 __x64_sys_openat2+0x55/0x70 fs/open.c:1471
 x64_sys_call+0x1121/0x3000 arch/x86/include/generated/asm/syscalls_64.h:438
 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

value changed: 0x00000001 -> 0x00000002

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 11674 Comm: syz.4.2993 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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