scsi: sd: Fix sshdr use in cache_type_store

If scsi_execute_cmd returns < 0, it doesn't initialize the sshdr, so we
shouldn't access the sshdr. If it returns 0, then the cmd executed
successfully, so there is no need to check the sshdr. This has us access
the sshdr when we get a return value > 0.

Signed-off-by: Mike Christie <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: John Garry <[email protected]>
Reviewed-by: Martin Wilck <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>

Author: mikechristie

drivers/scsi/sd.c

@@ -143,7 +143,7 @@ cache_type_store(struct device *dev, struct device_attribute *attr,
 	struct scsi_mode_data data;
 	struct scsi_sense_hdr sshdr;
 	static const char temp[] = "temporary ";
-	int len;
+	int len, ret;
 
 	if (sdp->type != TYPE_DISK && sdp->type != TYPE_ZBC)
 		/* no cache control on RBC devices; theoretically they
@@ -190,9 +190,10 @@ cache_type_store(struct device *dev, struct device_attribute *attr,
 	 */
 	data.device_specific = 0;
 
-	if (scsi_mode_select(sdp, 1, sp, buffer_data, len, SD_TIMEOUT,
-			     sdkp->max_retries, &data, &sshdr)) {
-		if (scsi_sense_valid(&sshdr))
+	ret = scsi_mode_select(sdp, 1, sp, buffer_data, len, SD_TIMEOUT,
+			       sdkp->max_retries, &data, &sshdr);
+	if (ret) {
+		if (ret > 0 && scsi_sense_valid(&sshdr))
 			sd_print_sense_hdr(sdkp, &sshdr);
 		return -EINVAL;
 	}