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BUG: KCSAN: data-race in fifo_open / wait_for_partner

read-write to 0xffff88814bbe6de4 of 4 bytes by task 20243 on cpu 0:
 fifo_open+0x86/0x5d0 fs/pipe.c:1132
 do_dentry_open+0x4be/0xa90 fs/open.c:947
 vfs_open+0x37/0x1e0 fs/open.c:1079
 do_open fs/namei.c:4699 [inline]
 path_openat+0x1b70/0x2050 fs/namei.c:4858
 do_file_open+0x16c/0x290 fs/namei.c:4887
 do_sys_openat2+0x94/0x130 fs/open.c:1364
 do_sys_open fs/open.c:1370 [inline]
 __do_sys_openat fs/open.c:1386 [inline]
 __se_sys_openat fs/open.c:1381 [inline]
 __x64_sys_openat+0xf2/0x120 fs/open.c:1381
 x64_sys_call+0x1e39/0x3020 arch/x86/include/generated/asm/syscalls_64.h:258
 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 0xffff88814bbe6de4 of 4 bytes by task 20240 on cpu 1:
 pipe_lock fs/pipe.c:90 [inline]
 wait_for_partner+0x117/0x1e0 fs/pipe.c:1109
 fifo_open+0x462/0x5d0 fs/pipe.c:1176
 do_dentry_open+0x4be/0xa90 fs/open.c:947
 vfs_open+0x37/0x1e0 fs/open.c:1079
 do_open fs/namei.c:4699 [inline]
 path_openat+0x1b70/0x2050 fs/namei.c:4858
 do_file_open+0x16c/0x290 fs/namei.c:4887
 do_sys_openat2+0x94/0x130 fs/open.c:1364
 __do_sys_openat2 fs/open.c:1413 [inline]
 __se_sys_openat2+0x193/0x1f0 fs/open.c:1389
 __x64_sys_openat2+0x55/0x70 fs/open.c:1389
 x64_sys_call+0x2170/0x3020 arch/x86/include/generated/asm/syscalls_64.h:438
 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

value changed: 0x00000001 -> 0x00000002

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 20240 Comm: syz.9.5776 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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