scsi: target: iscsi: Fix buffer overflow in lio_target_nacl_info_show()

In the Linux kernel, the following vulnerability has been resolved:

scsi: target: iscsi: Fix buffer overflow in lio_target_nacl_info_show()

The function lio_target_nacl_info_show() uses sprintf() in a loop to print details for every iSCSI connection in a session without checking for the buffer length. With enough iSCSI connections it's possible to overflow the buffer provided by configfs and corrupt the memory.

This patch replaces sprintf() with sysfs_emit_at() that checks for buffer boundries.