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BUG: KCSAN: data-race in do_sendfile / ksys_write

write to 0xffff88813af8ec40 of 8 bytes by task 13304 on cpu 0:
 do_sendfile+0x76b/0x980 fs/read_write.c:1269
 __do_sys_sendfile64 fs/read_write.c:1316 [inline]
 __se_sys_sendfile64 fs/read_write.c:1308 [inline]
 __x64_sys_sendfile64+0xbd/0x150 fs/read_write.c:1308
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

write to 0xffff88813af8ec40 of 8 bytes by task 13302 on cpu 1:
 ksys_write+0x11e/0x1a0 fs/read_write.c:639
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x42/0x50 fs/read_write.c:646
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x0000000000000000 -> 0x00000000000000b6

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 13302 Comm: syz-executor.4 Tainted: G        W          6.7.0-rc4-syzkaller-00009-gbee0e7762ad2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
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