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BUG: KCSAN: data-race in fifo_open / pipe_wait

write to 0xffff88809d0041ec of 4 bytes by task 30139 on cpu 0:
 put_pipe_info fs/pipe.c:707 [inline]
 fifo_open+0x30a/0x7b0 fs/pipe.c:1177
 do_dentry_open+0x580/0x8e0 fs/open.c:828
 vfs_open+0x43/0x50 fs/open.c:942
 do_open fs/namei.c:3243 [inline]
 path_openat+0x185f/0x20e0 fs/namei.c:3360
 do_filp_open+0xbd/0x1d0 fs/namei.c:3387
 do_sys_openat2+0x33c/0x4a0 fs/open.c:1179
 do_sys_open fs/open.c:1195 [inline]
 ksys_open include/linux/syscalls.h:1388 [inline]
 __do_sys_open fs/open.c:1201 [inline]
 __se_sys_open fs/open.c:1199 [inline]
 __x64_sys_open+0xe2/0x110 fs/open.c:1199
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88809d0041ec of 4 bytes by task 30150 on cpu 1:
 pipe_lock_nested fs/pipe.c:65 [inline]
 pipe_lock fs/pipe.c:74 [inline]
 pipe_wait+0xf8/0x140 fs/pipe.c:125
 wait_for_partner fs/pipe.c:1043 [inline]
 fifo_open+0x58b/0x7b0 fs/pipe.c:1111
 do_dentry_open+0x580/0x8e0 fs/open.c:828
 vfs_open+0x43/0x50 fs/open.c:942
 do_open fs/namei.c:3243 [inline]
 path_openat+0x185f/0x20e0 fs/namei.c:3360
 do_filp_open+0xbd/0x1d0 fs/namei.c:3387
 do_sys_openat2+0x33c/0x4a0 fs/open.c:1179
 do_sys_open fs/open.c:1195 [inline]
 ksys_open include/linux/syscalls.h:1388 [inline]
 __do_sys_open fs/open.c:1201 [inline]
 __se_sys_open fs/open.c:1199 [inline]
 __x64_sys_open+0xe2/0x110 fs/open.c:1199
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 30150 Comm: syz-executor.4 Not tainted 5.8.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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