[bug report] crypto: marvell - add support for OCTEON TX CPT engine

[Dan Carpenter <dan.carpenter@oracle.com>]

Hello SrujanaChalla,

This is a semi-automatic email about new static checker warnings.

The patch d9110b0b01ff: "crypto: marvell - add support for OCTEON TX 
CPT engine" from Mar 13, 2020, leads to the following Smatch 
complaint:

    drivers/crypto/marvell/octeontx/otx_cptpf_ucode.c:1300 create_engine_group()
    error: we previously assumed 'mirrored_eng_grp' could be null (see line 1256)

drivers/crypto/marvell/octeontx/otx_cptpf_ucode.c
  1255		mirrored_eng_grp = find_mirrored_eng_grp(eng_grp);
  1256		if (mirrored_eng_grp) {
                    ^^^^^^^^^^^^^^^^
The patch adds a check

  1257			/* Setup mirroring */
  1258			setup_eng_grp_mirroring(eng_grp, mirrored_eng_grp);
  1259	
  1260			/*
  1261			 * Update count of requested engines because some
  1262			 * of them might be shared with mirrored group
  1263			 */
  1264			update_requested_engs(mirrored_eng_grp, engs, engs_cnt);
  1265		}
  1266	
  1267		/* Reserve engines */
  1268		ret = reserve_engines(dev, eng_grp, engs, engs_cnt);
  1269		if (ret)
  1270			goto err_ucode_unload;
  1271	
  1272		/* Update ucode pointers used by engines */
  1273		update_ucode_ptrs(eng_grp);
  1274	
  1275		/* Update engine masks used by this group */
  1276		ret = eng_grp_update_masks(dev, eng_grp);
  1277		if (ret)
  1278			goto err_release_engs;
  1279	
  1280		/* Create sysfs entry for engine group info */
  1281		ret = create_sysfs_eng_grps_info(dev, eng_grp);
  1282		if (ret)
  1283			goto err_release_engs;
  1284	
  1285		/* Enable engine group */
  1286		ret = enable_eng_grp(eng_grp, eng_grps->obj);
  1287		if (ret)
  1288			goto err_release_engs;
  1289	
  1290		/*
  1291		 * If this engine group mirrors another engine group
  1292		 * then we need to unload ucode as we will use ucode
  1293		 * from mirrored engine group
  1294		 */
  1295		if (eng_grp->mirror.is_ena)
  1296			ucode_unload(dev, &eng_grp->ucode[0]);
  1297	
  1298		eng_grp->is_enabled = true;
  1299		if (eng_grp->mirror.is_ena)
  1300			dev_info(dev,
  1301				 "Engine_group%d: reuse microcode %s from group %d",
  1302				 eng_grp->idx, mirrored_eng_grp->ucode[0].ver_str,
                                               ^^^^^^^^^^^^^^^^^^
and an unchecked dereference.

regards,
dan carpenter