kobject_uevent: Fix OOB access within zap_modalias_env()

commit dd6e9894 upstream.

zap_modalias_env() wrongly calculates size of memory block to move, so
will cause OOB memory access issue if variable MODALIAS is not the last
one within its @env parameter, fixed by correcting size to memmove.

Fixes: 9b3fa47d ("kobject: fix suppressing modalias in uevents delivered over netlink")
Cc: stable@vger.kernel.org
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Reviewed-by: Lk Sii <lk_sii@163.com>
Link: https://lore.kernel.org/r/1717074877-11352-1-git-send-email-quic_zijuhu@quicinc.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>