failed to copy 'su.img' to '/data/su.img': Permission denied

failed to copy 'su.img' to '/data/su.img': Permission denied

C:\adb>fastboot getvar all
(bootloader) kernel: lk
(bootloader) product: htc_hiaeul
(bootloader) version: 1.0
(bootloader) imei: 35263707025////
(bootloader) version-main: 1.27.502.5
(bootloader) boot-mode: download
(bootloader) version-baseband: 1.0.U00297.1@51002.2
(bootloader) version-bootloader: 1.0.0.0000
(bootloader) mid: 2PQ912000
(bootloader) cid: CWS__001
all:
finished. total time: 0.028s

getprop ro.build.fingerprint
htc/hiaeul_00502/htc_hiaeul:6.0/MRA58K/656287.5:user/release-keys
shell@htc_hiaeul:/ $

How to solve????

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