syzbot

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BUG: KCSAN: data-race in fifo_open / wait_for_partner

read-write to 0xffff88813f0ad42c of 4 bytes by task 4981 on cpu 1:
 fifo_open+0x86/0x5d0 fs/pipe.c:1132
 do_dentry_open+0x54b/0xa60 fs/open.c:962
 vfs_open+0x37/0x1e0 fs/open.c:1094
 do_open fs/namei.c:4637 [inline]
 path_openat+0x1de9/0x23c0 fs/namei.c:4796
 do_filp_open+0x15d/0x280 fs/namei.c:4823
 do_sys_openat2+0xa6/0x150 fs/open.c:1430
 __do_sys_openat2 fs/open.c:1479 [inline]
 __se_sys_openat2+0x193/0x1f0 fs/open.c:1455
 __x64_sys_openat2+0x55/0x70 fs/open.c:1455
 x64_sys_call+0x2c04/0x3000 arch/x86/include/generated/asm/syscalls_64.h:438
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc0/0x2a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88813f0ad42c of 4 bytes by task 4965 on cpu 0:
 pipe_unlock fs/pipe.c:97 [inline]
 wait_for_partner+0xd5/0x1e0 fs/pipe.c:1106
 fifo_open+0x4b1/0x5d0 fs/pipe.c:1197
 do_dentry_open+0x54b/0xa60 fs/open.c:962
 vfs_open+0x37/0x1e0 fs/open.c:1094
 do_open fs/namei.c:4637 [inline]
 path_openat+0x1de9/0x23c0 fs/namei.c:4796
 do_filp_open+0x15d/0x280 fs/namei.c:4823
 do_sys_openat2+0xa6/0x150 fs/open.c:1430
 do_sys_open fs/open.c:1436 [inline]
 __do_sys_openat fs/open.c:1452 [inline]
 __se_sys_openat fs/open.c:1447 [inline]
 __x64_sys_openat+0xf2/0x120 fs/open.c:1447
 x64_sys_call+0x2b07/0x3000 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc0/0x2a0 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: 0 UID: 0 PID: 4965 Comm: syz.1.480 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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