[PATCH AUTOSEL 4.19 26/38] scsi: target: core: Do not overwrite CDB byte 1

[Sasha Levin]

From: Bodo Stroesser <bstroesser@xxxxxxxxxxxxxx>

[ Upstream commit 27e84243cb63601a10e366afe3e2d05bb03c1cb5 ]

passthrough_parse_cdb() - used by TCMU and PSCSI - attepts to reset the LUN
field of SCSI-2 CDBs (bits 5,6,7 of byte 1).  The current code is wrong as
for newer commands not having the LUN field it overwrites relevant command
bits (e.g. for SECURITY PROTOCOL IN / OUT). We think this code was
unnecessary from the beginning or at least it is no longer useful. So we
remove it entirely.

Link: https://lore.kernel.org/r/12498eab-76fd-eaad-1316-c2827badb76a@xxxxxxxxxxxxxx
Signed-off-by: Bodo Stroesser <bstroesser@xxxxxxxxxxxxxx>
Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx>
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/target/target_core_device.c | 21 ---------------------
 1 file changed, 21 deletions(-)

diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index 47b5ef153135c..e9ff2a7c0c0e6 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -1128,27 +1128,6 @@ passthrough_parse_cdb(struct se_cmd *cmd,
 	struct se_device *dev = cmd->se_dev;
 	unsigned int size;
 
-	/*
-	 * Clear a lun set in the cdb if the initiator talking to use spoke
-	 * and old standards version, as we can't assume the underlying device
-	 * won't choke up on it.
-	 */
-	switch (cdb[0]) {
-	case READ_10: /* SBC - RDProtect */
-	case READ_12: /* SBC - RDProtect */
-	case READ_16: /* SBC - RDProtect */
-	case SEND_DIAGNOSTIC: /* SPC - SELF-TEST Code */
-	case VERIFY: /* SBC - VRProtect */
-	case VERIFY_16: /* SBC - VRProtect */
-	case WRITE_VERIFY: /* SBC - VRProtect */
-	case WRITE_VERIFY_12: /* SBC - VRProtect */
-	case MAINTENANCE_IN: /* SPC - Parameter Data Format for SA RTPG */
-		break;
-	default:
-		cdb[1] &= 0x1f; /* clear logical unit number */
-		break;
-	}
-
 	/*
 	 * For REPORT LUNS we always need to emulate the response, for everything
 	 * else, pass it up.
-- 
2.20.1