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BUG: KCSAN: data-race in alloc_fd / do_select

write to 0xffff88811d1cc960 of 8 bytes by task 3924 on cpu 1:
 instrument_write include/linux/instrumented.h:41 [inline]
 ___set_bit include/asm-generic/bitops/instrumented-non-atomic.h:28 [inline]
 __set_open_fd fs/file.c:262 [inline]
 alloc_fd+0x1d5/0x370 fs/file.c:538
 __get_unused_fd_flags fs/file.c:559 [inline]
 get_unused_fd_flags+0x44/0x50 fs/file.c:564
 __do_sys_memfd_secret mm/secretmem.c:247 [inline]
 __se_sys_memfd_secret+0xc5/0x2c0 mm/secretmem.c:231
 __x64_sys_memfd_secret+0x1f/0x30 mm/secretmem.c:231
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff88811d1cc960 of 8 bytes by task 3925 on cpu 0:
 max_select_fd fs/select.c:447 [inline]
 do_select+0x2a2/0xf90 fs/select.c:490
 core_sys_select+0x361/0x520 fs/select.c:681
 do_pselect fs/select.c:763 [inline]
 __do_sys_pselect6 fs/select.c:804 [inline]
 __se_sys_pselect6+0x213/0x280 fs/select.c:795
 __x64_sys_pselect6+0x78/0x90 fs/select.c:795
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0001ffffffffffff -> 0x003fffffffffffff

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 3925 Comm: syz-executor.1 Not tainted 6.5.0-rc7-syzkaller-00004-gf7757129e3de #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
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