CVE-2022-21546

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

scsi: target: Fix WRITE_SAME No Data Buffer crash

In newer version of the SBC specs, we have a NDOB bit that indicates there

is no data buffer that gets written out. If this bit is set using commands

like "sg_write_same --ndob" we will crash in target_core_iblock/file's

execute_write_same handlers when we go to access the se_cmd->t_data_sg

because its NULL.

This patch adds a check for the NDOB bit in the common WRITE SAME code

because we don't support it. And, it adds a check for zero SG elements in

each handler in case the initiator tries to send a normal WRITE SAME with

no data buffer.