scsi: lpfc: change snprintf to scnprintf for possible overflow

Change snprintf to scnprintf. There are generally two cases where using
snprintf causes problems.

1) Uses of size += snprintf(buf, SIZE - size, fmt, ...)
In this case, if snprintf would have written more characters than what the
buffer size (SIZE) is, then size will end up larger than SIZE. In later
uses of snprintf, SIZE - size will result in a negative number, leading
to problems. Note that size might already be too large by using
size = snprintf before the code reaches a case of size += snprintf.

2) If size is ultimately used as a length parameter for a copy back to user
space, then it will potentially allow for a buffer overflow and information
disclosure when size is greater than SIZE. When the size is used to index
the buffer directly, we can have memory corruption. This also means when
size = snprintf... is used, it may also cause problems since size may become
large.  Copying to userspace is mitigated by the HARDENED_USERCOPY kernel
configuration.

The solution to these issues is to use scnprintf which returns the number of
characters actually written to the buffer, so the size variable will never
exceed SIZE.

Signed-off-by: Silvio Cesare <silvio.cesare@gmail.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: James Smart <james.smart@broadcom.com>
Cc: Dick Kennedy <dick.kennedy@broadcom.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 100 insertions, 96 deletions

diff --git a/drivers/scsi/lpfc/lpfc_attr.c b/drivers/scsi/lpfc/lpfc_attr.c
index 0612da04181b..786413cbb907 100644
--- a/drivers/scsi/lpfc/lpfc_attr.c
+++ b/drivers/scsi/lpfc/lpfc_attr.c
@@ -114,7 +114,7 @@ static ssize_t
 lpfc_drvr_version_show(struct device *dev, struct device_attribute *attr,
 		       char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, LPFC_MODULE_DESC "\n");
+	return scnprintf(buf, PAGE_SIZE, LPFC_MODULE_DESC "\n");
 }
 
 /**
@@ -134,9 +134,9 @@ lpfc_enable_fip_show(struct device *dev, struct device_attribute *attr,
 	struct lpfc_hba   *phba = vport->phba;
 
 	if (phba->hba_flag & HBA_FIP_SUPPORT)
-		return snprintf(buf, PAGE_SIZE, "1\n");
+		return scnprintf(buf, PAGE_SIZE, "1\n");
 	else
-		return snprintf(buf, PAGE_SIZE, "0\n");
+		return scnprintf(buf, PAGE_SIZE, "0\n");
 }
 
 static ssize_t
@@ -564,14 +564,15 @@ lpfc_bg_info_show(struct device *dev, struct device_attribute *attr,
 	struct lpfc_vport *vport = (struct lpfc_vport *) shost->hostdata;
 	struct lpfc_hba   *phba = vport->phba;
 
-	if (phba->cfg_enable_bg)
+	if (phba->cfg_enable_bg) {
 		if (phba->sli3_options & LPFC_SLI3_BG_ENABLED)
-			return snprintf(buf, PAGE_SIZE, "BlockGuard Enabled\n");
+			return scnprintf(buf, PAGE_SIZE,
+					"BlockGuard Enabled\n");
 		else
-			return snprintf(buf, PAGE_SIZE,
+			return scnprintf(buf, PAGE_SIZE,
 					"BlockGuard Not Supported\n");
-	else
-			return snprintf(buf, PAGE_SIZE,
+	} else
+		return scnprintf(buf, PAGE_SIZE,
 					"BlockGuard Disabled\n");
 }
 
@@ -583,7 +584,7 @@ lpfc_bg_guard_err_show(struct device *dev, struct device_attribute *attr,
 	struct lpfc_vport *vport = (struct lpfc_vport *) shost->hostdata;
 	struct lpfc_hba   *phba = vport->phba;
 
-	return snprintf(buf, PAGE_SIZE, "%llu\n",
+	return scnprintf(buf, PAGE_SIZE, "%llu\n",
 			(unsigned long long)phba->bg_guard_err_cnt);
 }
 
@@ -595,7 +596,7 @@ lpfc_bg_apptag_err_show(struct device *dev, struct device_attribute *attr,
 	struct lpfc_vport *vport = (struct lpfc_vport *) shost->hostdata;
 	struct lpfc_hba   *phba = vport->phba;
 
-	return snprintf(buf, PAGE_SIZE, "%llu\n",
+	return scnprintf(buf, PAGE_SIZE, "%llu\n",
 			(unsigned long long)phba->bg_apptag_err_cnt);
 }
 
@@ -607,7 +608,7 @@ lpfc_bg_reftag_err_show(struct device *dev, struct device_attribute *attr,
 	struct lpfc_vport *vport = (struct lpfc_vport *) shost->hostdata;
 	struct lpfc_hba   *phba = vport->phba;
 
-	return snprintf(buf, PAGE_SIZE, "%llu\n",
+	return scnprintf(buf, PAGE_SIZE, "%llu\n",
 			(unsigned long long)phba->bg_reftag_err_cnt);
 }
 
@@ -625,7 +626,7 @@ lpfc_info_show(struct device *dev, struct device_attribute *attr,
 {
 	struct Scsi_Host *host = class_to_shost(dev);
 
-	return snprintf(buf, PAGE_SIZE, "%s\n",lpfc_info(host));
+	return scnprintf(buf, PAGE_SIZE, "%s\n", lpfc_info(host));
 }
 
 /**
@@ -644,7 +645,7 @@ lpfc_serialnum_show(struct device *dev, struct device_attribute *attr,
 	struct lpfc_vport *vport = (struct lpfc_vport *) shost->hostdata;
 	struct lpfc_hba   *phba = vport->phba;
 
-	return snprintf(buf, PAGE_SIZE, "%s\n",phba->SerialNumber);
+	return scnprintf(buf, PAGE_SIZE, "%s\n", phba->SerialNumber);
 }
 
 /**
@@ -666,7 +667,7 @@ lpfc_temp_sensor_show(struct device *dev, struct device_attribute *attr,
 	struct Scsi_Host *shost = class_to_shost(dev);
 	struct lpfc_vport *vport = (struct lpfc_vport *) shost->hostdata;
 	struct lpfc_hba   *phba = vport->phba;
-	return snprintf(buf, PAGE_SIZE, "%d\n",phba->temp_sensor_support);
+	return scnprintf(buf, PAGE_SIZE, "%d\n", phba->temp_sensor_support);
 }
 
 /**
@@ -685,7 +686,7 @@ lpfc_modeldesc_show(struct device *dev, struct device_attribute *attr,
 	struct lpfc_vport *vport = (struct lpfc_vport *) shost->hostdata;
 	struct lpfc_hba   *phba = vport->phba;
 
-	return snprintf(buf, PAGE_SIZE, "%s\n",phba->ModelDesc);
+	return scnprintf(buf, PAGE_SIZE, "%s\n", phba->ModelDesc);
 }
 
 /**
@@ -704,7 +705,7 @@ lpfc_modelname_show(struct device *dev, struct device_attribute *attr,
 	struct lpfc_vport *vport = (struct lpfc_vport *) shost->hostdata;
 	struct lpfc_hba   *phba = vport->phba;
 
-	return snprintf(buf, PAGE_SIZE, "%s\n",phba->ModelName);
+	return scnprintf(buf, PAGE_SIZE, "%s\n", phba->ModelName);
 }
 
 /**
@@ -723,7 +724,7 @@ lpfc_programtype_show(struct device *dev, struct device_attribute *attr,
 	struct lpfc_vport *vport = (struct lpfc_vport *) shost->hostdata;
 	struct lpfc_hba   *phba = vport->phba;
 
-	return snprintf(buf, PAGE_SIZE, "%s\n",phba->ProgramType);
+	return scnprintf(buf, PAGE_SIZE, "%s\n", phba->ProgramType);
 }
 
 /**
@@ -741,7 +742,7 @@ lpfc_mlomgmt_show(struct device *dev, struct device_attribute *attr, char *buf)
 	struct lpfc_vport *vport = (struct lpfc_vport *)shost->hostdata;
 	struct lpfc_hba   *phba = vport->phba;
 
-	return snprintf(buf, PAGE_SIZE, "%d\n",
+	return scnprintf(buf, PAGE_SIZE, "%d\n",
 		(phba->sli.sli_flag & LPFC_MENLO_MAINT));
 }
 
@@ -761,7 +762,7 @@ lpfc_vportnum_show(struct device *dev, struct device_attribute *attr,
 	struct lpfc_vport *vport = (struct lpfc_vport *) shost->hostdata;
 	struct lpfc_hba   *phba = vport->phba;
 
-	return snprintf(buf, PAGE_SIZE, "%s\n",phba->Port);
+	return scnprintf(buf, PAGE_SIZE, "%s\n", phba->Port);
 }
 
 /**
@@ -789,10 +790,10 @@ lpfc_fwrev_show(struct device *dev, struct device_attribute *attr,
 	sli_family = phba->sli4_hba.pc_sli4_params.sli_family;
 
 	if (phba->sli_rev < LPFC_SLI_REV4)
-		len = snprintf(buf, PAGE_SIZE, "%s, sli-%d\n",
+		len = scnprintf(buf, PAGE_SIZE, "%s, sli-%d\n",
 			       fwrev, phba->sli_rev);
 	else
-		len = snprintf(buf, PAGE_SIZE, "%s, sli-%d:%d:%x\n",
+		len = scnprintf(buf, PAGE_SIZE, "%s, sli-%d:%d:%x\n",
 			       fwrev, phba->sli_rev, if_type, sli_family);
 
 	return len;
@@ -816,7 +817,7 @@ lpfc_hdw_show(struct device *dev, struct device_attribute *attr, char *buf)
 	lpfc_vpd_t *vp = &phba->vpd;
 
 	lpfc_jedec_to_ascii(vp->rev.biuRev, hdw);
-	return snprintf(buf, PAGE_SIZE, "%s\n", hdw);
+	return scnprintf(buf, PAGE_SIZE, "%s\n", hdw);
 }
 
 /**
@@ -837,10 +838,11 @@ lpfc_option_rom_version_show(struct device *dev, struct device_attribute *attr,
 	char fwrev[FW_REV_STR_SIZE];
 
 	if (phba->sli_rev < LPFC_SLI_REV4)
-		return snprintf(buf, PAGE_SIZE, "%s\n", phba->OptionROMVersion);
+		return scnprintf(buf, PAGE_SIZE, "%s\n",
+				phba->OptionROMVersion);
 
 	lpfc_decode_firmware_rev(phba, fwrev, 1);
-	return snprintf(buf, PAGE_SIZE, "%s\n", fwrev);
+	return scnprintf(buf, PAGE_SIZE, "%s\n", fwrev);
 }
 
 /**
@@ -871,20 +873,20 @@ lpfc_link_state_show(struct device *dev, struct device_attribute *attr,
 	case LPFC_LINK_DOWN:
 	case LPFC_HBA_ERROR:
 		if (phba->hba_flag & LINK_DISABLED)
-			len += snprintf(buf + len, PAGE_SIZE-len,
+			len += scnprintf(buf + len, PAGE_SIZE-len,
 				"Link Down - User disabled\n");
 		else
-			len += snprintf(buf + len, PAGE_SIZE-len,
+			len += scnprintf(buf + len, PAGE_SIZE-len,
 				"Link Down\n");
 		break;
 	case LPFC_LINK_UP:
 	case LPFC_CLEAR_LA:
 	case LPFC_HBA_READY:
-		len += snprintf(buf + len, PAGE_SIZE-len, "Link Up - ");
+		len += scnprintf(buf + len, PAGE_SIZE-len, "Link Up - ");
 
 		switch (vport->port_state) {
 		case LPFC_LOCAL_CFG_LINK:
-			len += snprintf(buf + len, PAGE_SIZE-len,
+			len += scnprintf(buf + len, PAGE_SIZE-len,
 					"Configuring Link\n");
 			break;
 		case LPFC_FDISC:
@@ -894,38 +896,40 @@ lpfc_link_state_show(struct device *dev, struct device_attribute *attr,
 		case LPFC_NS_QRY:
 		case LPFC_BUILD_DISC_LIST:
 		case LPFC_DISC_AUTH:
-			len += snprintf(buf + len, PAGE_SIZE - len,
+			len += scnprintf(buf + len, PAGE_SIZE - len,
 					"Discovery\n");
 			break;
 		case LPFC_VPORT_READY:
-			len += snprintf(buf + len, PAGE_SIZE - len, "Ready\n");
+			len += scnprintf(buf + len, PAGE_SIZE - len,
+					"Ready\n");
 			break;
 
 		case LPFC_VPORT_FAILED:
-			len += snprintf(buf + len, PAGE_SIZE - len, "Failed\n");
+			len += scnprintf(buf + len, PAGE_SIZE - len,
+					"Failed\n");
 			break;
 
 		case LPFC_VPORT_UNKNOWN:
-			len += snprintf(buf + len, PAGE_SIZE - len,
+			len += scnprintf(buf + len, PAGE_SIZE - len,
 					"Unknown\n");
 			break;
 		}
 		if (phba->sli.sli_flag & LPFC_MENLO_MAINT)
-			len += snprintf(buf + len, PAGE_SIZE-len,
+			len += scnprintf(buf + len, PAGE_SIZE-len,
 					"   Menlo Maint Mode\n");
 		else if (phba->fc_topology == LPFC_TOPOLOGY_LOOP) {
 			if (vport->fc_flag & FC_PUBLIC_LOOP)
-				len += snprintf(buf + len, PAGE_SIZE-len,
+				len += scnprintf(buf + len, PAGE_SIZE-len,
 						"   Public Loop\n");
 			else
-				len += snprintf(buf + len, PAGE_SIZE-len,
+				len += scnprintf(buf + len, PAGE_SIZE-len,
 						"   Private Loop\n");
 		} else {
 			if (vport->fc_flag & FC_FABRIC)
-				len += snprintf(buf + len, PAGE_SIZE-len,
+				len += scnprintf(buf + len, PAGE_SIZE-len,
 						"   Fabric\n");
 			else
-				len += snprintf(buf + len, PAGE_SIZE-len,
+				len += scnprintf(buf + len, PAGE_SIZE-len,
 						"   Point-2-Point\n");
 		}
 	}
@@ -937,28 +941,28 @@ lpfc_link_state_show(struct device *dev, struct device_attribute *attr,
 		struct lpfc_trunk_link link = phba->trunk_link;
 
 		if (bf_get(lpfc_conf_trunk_port0, &phba->sli4_hba))
-			len += snprintf(buf + len, PAGE_SIZE - len,
+			len += scnprintf(buf + len, PAGE_SIZE - len,
 				"Trunk port 0: Link %s %s\n",
 				(link.link0.state == LPFC_LINK_UP) ?
 				 "Up" : "Down. ",
 				trunk_errmsg[link.link0.fault]);
 
 		if (bf_get(lpfc_conf_trunk_port1, &phba->sli4_hba))
-			len += snprintf(buf + len, PAGE_SIZE - len,
+			len += scnprintf(buf + len, PAGE_SIZE - len,
 				"Trunk port 1: Link %s %s\n",
 				(link.link1.state == LPFC_LINK_UP) ?
 				 "Up" : "Down. ",
 				trunk_errmsg[link.link1.fault]);
 
 		if (bf_get(lpfc_conf_trunk_port2, &phba->sli4_hba))
-			len += snprintf(buf + len, PAGE_SIZE - len,
+			len += scnprintf(buf + len, PAGE_SIZE - len,
 				"Trunk port 2: Link %s %s\n",
 				(link.link2.state == LPFC_LINK_UP) ?
 				 "Up" : "Down. ",
 				trunk_errmsg[link.link2.fault]);
 
 		if (bf_get(lpfc_conf_trunk_port3, &phba->sli4_hba))
-			len += snprintf(buf + len, PAGE_SIZE - len,
+			len += scnprintf(buf + len, PAGE_SIZE - len,
 				"Trunk port 3: Link %s %s\n",
 				(link.link3.state == LPFC_LINK_UP) ?
 				 "Up" : "Down. ",
@@ -986,15 +990,15 @@ lpfc_sli4_protocol_show(struct device *dev, struct device_attribute *attr,
 	struct lpfc_hba *phba = vport->phba;
 
 	if (phba->sli_rev < LPFC_SLI_REV4)
-		return snprintf(buf, PAGE_SIZE, "fc\n");
+		return scnprintf(buf, PAGE_SIZE, "fc\n");
 
 	if (phba->sli4_hba.lnk_info.lnk_dv == LPFC_LNK_DAT_VAL) {
 		if (phba->sli4_hba.lnk_info.lnk_tp == LPFC_LNK_TYPE_GE)
-			return snprintf(buf, PAGE_SIZE, "fcoe\n");
+			return scnprintf(buf, PAGE_SIZE, "fcoe\n");
 		if (phba->sli4_hba.lnk_info.lnk_tp == LPFC_LNK_TYPE_FC)
-			return snprintf(buf, PAGE_SIZE, "fc\n");
+			return scnprintf(buf, PAGE_SIZE, "fc\n");
 	}
-	return snprintf(buf, PAGE_SIZE, "unknown\n");
+	return scnprintf(buf, PAGE_SIZE, "unknown\n");
 }
 
 /**
@@ -1014,7 +1018,7 @@ lpfc_oas_supported_show(struct device *dev, struct device_attribute *attr,
 	struct lpfc_vport *vport = (struct lpfc_vport *)shost->hostdata;
 	struct lpfc_hba *phba = vport->phba;
 
-	return snprintf(buf, PAGE_SIZE, "%d\n",
+	return scnprintf(buf, PAGE_SIZE, "%d\n",
 			phba->sli4_hba.pc_sli4_params.oas_supported);
 }
 
@@ -1072,7 +1076,7 @@ lpfc_num_discovered_ports_show(struct device *dev,
 	struct Scsi_Host  *shost = class_to_shost(dev);
 	struct lpfc_vport *vport = (struct lpfc_vport *) shost->hostdata;
 
-	return snprintf(buf, PAGE_SIZE, "%d\n",
+	return scnprintf(buf, PAGE_SIZE, "%d\n",
 			vport->fc_map_cnt + vport->fc_unmap_cnt);
 }
 
@@ -1605,7 +1609,7 @@ lpfc_nport_evt_cnt_show(struct device *dev, struct device_attribute *attr,
 	struct lpfc_vport *vport = (struct lpfc_vport *) shost->hostdata;
 	struct lpfc_hba   *phba = vport->phba;
 
-	return snprintf(buf, PAGE_SIZE, "%d\n", phba->nport_event_cnt);
+	return scnprintf(buf, PAGE_SIZE, "%d\n", phba->nport_event_cnt);
 }
 
 int
@@ -1694,7 +1698,7 @@ lpfc_board_mode_show(struct device *dev, struct device_attribute *attr,
 	else
 		state = "online";
 
-	return snprintf(buf, PAGE_SIZE, "%s\n", state);
+	return scnprintf(buf, PAGE_SIZE, "%s\n", state);
 }
 
 /**
@@ -1920,8 +1924,8 @@ lpfc_max_rpi_show(struct device *dev, struct device_attribute *attr,
 	uint32_t cnt;
 
 	if (lpfc_get_hba_info(phba, NULL, NULL, &cnt, NULL, NULL, NULL))
-		return snprintf(buf, PAGE_SIZE, "%d\n", cnt);
-	return snprintf(buf, PAGE_SIZE, "Unknown\n");
+		return scnprintf(buf, PAGE_SIZE, "%d\n", cnt);
+	return scnprintf(buf, PAGE_SIZE, "Unknown\n");
 }
 
 /**
@@ -1948,8 +1952,8 @@ lpfc_used_rpi_show(struct device *dev, struct device_attribute *attr,
 	uint32_t cnt, acnt;
 
 	if (lpfc_get_hba_info(phba, NULL, NULL, &cnt, &acnt, NULL, NULL))
-		return snprintf(buf, PAGE_SIZE, "%d\n", (cnt - acnt));
-	return snprintf(buf, PAGE_SIZE, "Unknown\n");
+		return scnprintf(buf, PAGE_SIZE, "%d\n", (cnt - acnt));
+	return scnprintf(buf, PAGE_SIZE, "Unknown\n");
 }
 
 /**
@@ -1976,8 +1980,8 @@ lpfc_max_xri_show(struct device *dev, struct device_attribute *attr,
 	uint32_t cnt;
 
 	if (lpfc_get_hba_info(phba, &cnt, NULL, NULL, NULL, NULL, NULL))
-		return snprintf(buf, PAGE_SIZE, "%d\n", cnt);
-	return snprintf(buf, PAGE_SIZE, "Unknown\n");
+		return scnprintf(buf, PAGE_SIZE, "%d\n", cnt);
+	return scnprintf(buf, PAGE_SIZE, "Unknown\n");
 }
 
 /**
@@ -2004,8 +2008,8 @@ lpfc_used_xri_show(struct device *dev, struct device_attribute *attr,
 	uint32_t cnt, acnt;
 
 	if (lpfc_get_hba_info(phba, &cnt, &acnt, NULL, NULL, NULL, NULL))
-		return snprintf(buf, PAGE_SIZE, "%d\n", (cnt - acnt));
-	return snprintf(buf, PAGE_SIZE, "Unknown\n");
+		return scnprintf(buf, PAGE_SIZE, "%d\n", (cnt - acnt));
+	return scnprintf(buf, PAGE_SIZE, "Unknown\n");
 }
 
 /**
@@ -2032,8 +2036,8 @@ lpfc_max_vpi_show(struct device *dev, struct device_attribute *attr,
 	uint32_t cnt;
 
 	if (lpfc_get_hba_info(phba, NULL, NULL, NULL, NULL, &cnt, NULL))
-		return snprintf(buf, PAGE_SIZE, "%d\n", cnt);
-	return snprintf(buf, PAGE_SIZE, "Unknown\n");
+		return scnprintf(buf, PAGE_SIZE, "%d\n", cnt);
+	return scnprintf(buf, PAGE_SIZE, "Unknown\n");
 }
 
 /**
@@ -2060,8 +2064,8 @@ lpfc_used_vpi_show(struct device *dev, struct device_attribute *attr,
 	uint32_t cnt, acnt;
 
 	if (lpfc_get_hba_info(phba, NULL, NULL, NULL, NULL, &cnt, &acnt))
-		return snprintf(buf, PAGE_SIZE, "%d\n", (cnt - acnt));
-	return snprintf(buf, PAGE_SIZE, "Unknown\n");
+		return scnprintf(buf, PAGE_SIZE, "%d\n", (cnt - acnt));
+	return scnprintf(buf, PAGE_SIZE, "Unknown\n");
 }
 
 /**
@@ -2086,10 +2090,10 @@ lpfc_npiv_info_show(struct device *dev, struct device_attribute *attr,
 	struct lpfc_hba   *phba = vport->phba;
 
 	if (!(phba->max_vpi))
-		return snprintf(buf, PAGE_SIZE, "NPIV Not Supported\n");
+		return scnprintf(buf, PAGE_SIZE, "NPIV Not Supported\n");
 	if (vport->port_type == LPFC_PHYSICAL_PORT)
-		return snprintf(buf, PAGE_SIZE, "NPIV Physical\n");
-	return snprintf(buf, PAGE_SIZE, "NPIV Virtual (VPI %d)\n", vport->vpi);
+		return scnprintf(buf, PAGE_SIZE, "NPIV Physical\n");
+	return scnprintf(buf, PAGE_SIZE, "NPIV Virtual (VPI %d)\n", vport->vpi);
 }
 
 /**
@@ -2111,7 +2115,7 @@ lpfc_poll_show(struct device *dev, struct device_attribute *attr,
 	struct lpfc_vport *vport = (struct lpfc_vport *) shost->hostdata;
 	struct lpfc_hba   *phba = vport->phba;
 
-	return snprintf(buf, PAGE_SIZE, "%#x\n", phba->cfg_poll);
+	return scnprintf(buf, PAGE_SIZE, "%#x\n", phba->cfg_poll);
 }
 
 /**
@@ -2215,7 +2219,7 @@ lpfc_fips_level_show(struct device *dev,  struct device_attribute *attr,
 	struct lpfc_vport *vport = (struct lpfc_vport *) shost->hostdata;
 	struct lpfc_hba   *phba = vport->phba;
 
-	return snprintf(buf, PAGE_SIZE, "%d\n", phba->fips_level);
+	return scnprintf(buf, PAGE_SIZE, "%d\n", phba->fips_level);
 }
 
 /**
@@ -2234,7 +2238,7 @@ lpfc_fips_rev_show(struct device *dev,  struct device_attribute *attr,
 	struct lpfc_vport *vport = (struct lpfc_vport *) shost->hostdata;
 	struct lpfc_hba   *phba = vport->phba;
 
-	return snprintf(buf, PAGE_SIZE, "%d\n", phba->fips_spec_rev);
+	return scnprintf(buf, PAGE_SIZE, "%d\n", phba->fips_spec_rev);
 }
 
 /**
@@ -2253,7 +2257,7 @@ lpfc_dss_show(struct device *dev, struct device_attribute *attr,
 	struct lpfc_vport *vport = (struct lpfc_vport *) shost->hostdata;
 	struct lpfc_hba   *phba = vport->phba;
 
-	return snprintf(buf, PAGE_SIZE, "%s - %sOperational\n",
+	return scnprintf(buf, PAGE_SIZE, "%s - %sOperational\n",
 			(phba->cfg_enable_dss) ? "Enabled" : "Disabled",
 			(phba->sli3_options & LPFC_SLI3_DSS_ENABLED) ?
 				"" : "Not ");
@@ -2282,7 +2286,7 @@ lpfc_sriov_hw_max_virtfn_show(struct device *dev,
 	uint16_t max_nr_virtfn;
 
 	max_nr_virtfn = lpfc_sli_sriov_nr_virtfn_get(phba);
-	return snprintf(buf, PAGE_SIZE, "%d\n", max_nr_virtfn);
+	return scnprintf(buf, PAGE_SIZE, "%d\n", max_nr_virtfn);
 }
 
 static inline bool lpfc_rangecheck(uint val, uint min, uint max)
@@ -2342,7 +2346,7 @@ lpfc_##attr##_show(struct device *dev, struct device_attribute *attr, \
 	struct Scsi_Host  *shost = class_to_shost(dev);\
 	struct lpfc_vport *vport = (struct lpfc_vport *) shost->hostdata;\
 	struct lpfc_hba   *phba = vport->phba;\
-	return snprintf(buf, PAGE_SIZE, "%d\n",\
+	return scnprintf(buf, PAGE_SIZE, "%d\n",\
 			phba->cfg_##attr);\
 }
 
@@ -2370,7 +2374,7 @@ lpfc_##attr##_show(struct device *dev, struct device_attribute *attr, \
 	struct lpfc_hba   *phba = vport->phba;\
 	uint val = 0;\
 	val = phba->cfg_##attr;\
-	return snprintf(buf, PAGE_SIZE, "%#x\n",\
+	return scnprintf(buf, PAGE_SIZE, "%#x\n",\
 			phba->cfg_##attr);\
 }
 
@@ -2506,7 +2510,7 @@ lpfc_##attr##_show(struct device *dev, struct device_attribute *attr, \
 { \
 	struct Scsi_Host  *shost = class_to_shost(dev);\
 	struct lpfc_vport *vport = (struct lpfc_vport *) shost->hostdata;\
-	return snprintf(buf, PAGE_SIZE, "%d\n", vport->cfg_##attr);\
+	return scnprintf(buf, PAGE_SIZE, "%d\n", vport->cfg_##attr);\
 }
 
 /**
@@ -2531,7 +2535,7 @@ lpfc_##attr##_show(struct device *dev, struct device_attribute *attr, \
 { \
 	struct Scsi_Host  *shost = class_to_shost(dev);\
 	struct lpfc_vport *vport = (struct lpfc_vport *) shost->hostdata;\
-	return snprintf(buf, PAGE_SIZE, "%#x\n", vport->cfg_##attr);\
+	return scnprintf(buf, PAGE_SIZE, "%#x\n", vport->cfg_##attr);\
 }
 
 /**
@@ -2803,7 +2807,7 @@ lpfc_soft_wwpn_show(struct device *dev, struct device_attribute *attr,
 	struct lpfc_vport *vport = (struct lpfc_vport *) shost->hostdata;
 	struct lpfc_hba   *phba = vport->phba;
 
-	return snprintf(buf, PAGE_SIZE, "0x%llx\n",
+	return scnprintf(buf, PAGE_SIZE, "0x%llx\n",
 			(unsigned long long)phba->cfg_soft_wwpn);
 }
 
@@ -2900,7 +2904,7 @@ lpfc_soft_wwnn_show(struct device *dev, struct device_attribute *attr,
 {
 	struct Scsi_Host *shost = class_to_shost(dev);
 	struct lpfc_hba *phba = ((struct lpfc_vport *)shost->hostdata)->phba;
-	return snprintf(buf, PAGE_SIZE, "0x%llx\n",
+	return scnprintf(buf, PAGE_SIZE, "0x%llx\n",
 			(unsigned long long)phba->cfg_soft_wwnn);
 }
 
@@ -2966,7 +2970,7 @@ lpfc_oas_tgt_show(struct device *dev, struct device_attribute *attr,
 	struct Scsi_Host *shost = class_to_shost(dev);
 	struct lpfc_hba *phba = ((struct lpfc_vport *)shost->hostdata)->phba;
 
-	return snprintf(buf, PAGE_SIZE, "0x%llx\n",
+	return scnprintf(buf, PAGE_SIZE, "0x%llx\n",
 			wwn_to_u64(phba->cfg_oas_tgt_wwpn));
 }
 
@@ -3034,7 +3038,7 @@ lpfc_oas_priority_show(struct device *dev, struct device_attribute *attr,
 	struct Scsi_Host *shost = class_to_shost(dev);
 	struct lpfc_hba *phba = ((struct lpfc_vport *)shost->hostdata)->phba;
 
-	return snprintf(buf, PAGE_SIZE, "%d\n", phba->cfg_oas_priority);
+	return scnprintf(buf, PAGE_SIZE, "%d\n", phba->cfg_oas_priority);
 }
 
 /**
@@ -3097,7 +3101,7 @@ lpfc_oas_vpt_show(struct device *dev, struct device_attribute *attr,
 	struct Scsi_Host *shost = class_to_shost(dev);
 	struct lpfc_hba *phba = ((struct lpfc_vport *)shost->hostdata)->phba;
 
-	return snprintf(buf, PAGE_SIZE, "0x%llx\n",
+	return scnprintf(buf, PAGE_SIZE, "0x%llx\n",
 			wwn_to_u64(phba->cfg_oas_vpt_wwpn));
 }
 
@@ -3168,7 +3172,7 @@ lpfc_oas_lun_state_show(struct device *dev, struct device_attribute *attr,
 	struct Scsi_Host *shost = class_to_shost(dev);
 	struct lpfc_hba *phba = ((struct lpfc_vport *)shost->hostdata)->phba;
 
-	return snprintf(buf, PAGE_SIZE, "%d\n", phba->cfg_oas_lun_state);
+	return scnprintf(buf, PAGE_SIZE, "%d\n", phba->cfg_oas_lun_state);
 }
 
 /**
@@ -3232,7 +3236,7 @@ lpfc_oas_lun_status_show(struct device *dev, struct device_attribute *attr,
 	if (!(phba->cfg_oas_flags & OAS_LUN_VALID))
 		return -EFAULT;
 
-	return snprintf(buf, PAGE_SIZE, "%d\n", phba->cfg_oas_lun_status);
+	return scnprintf(buf, PAGE_SIZE, "%d\n", phba->cfg_oas_lun_status);
 }
 static DEVICE_ATTR(lpfc_xlane_lun_status, S_IRUGO,
 		   lpfc_oas_lun_status_show, NULL);
@@ -3384,7 +3388,7 @@ lpfc_oas_lun_show(struct device *dev, struct device_attribute *attr,
 	if (oas_lun != NOT_OAS_ENABLED_LUN)
 		phba->cfg_oas_flags |= OAS_LUN_VALID;
 
-	len += snprintf(buf + len, PAGE_SIZE-len, "0x%llx", oas_lun);
+	len += scnprintf(buf + len, PAGE_SIZE-len, "0x%llx", oas_lun);
 
 	return len;
 }
@@ -3518,7 +3522,7 @@ lpfc_iocb_hw_show(struct device *dev, struct device_attribute *attr, char *buf)
 	struct Scsi_Host  *shost = class_to_shost(dev);
 	struct lpfc_hba   *phba = ((struct lpfc_vport *) shost->hostdata)->phba;
 
-	return snprintf(buf, PAGE_SIZE, "%d\n", phba->iocb_max);
+	return scnprintf(buf, PAGE_SIZE, "%d\n", phba->iocb_max);
 }
 
 static DEVICE_ATTR(iocb_hw, S_IRUGO,
@@ -3530,7 +3534,7 @@ lpfc_txq_hw_show(struct device *dev, struct device_attribute *attr, char *buf)
 	struct lpfc_hba   *phba = ((struct lpfc_vport *) shost->hostdata)->phba;
 	struct lpfc_sli_ring *pring = lpfc_phba_elsring(phba);
 
-	return snprintf(buf, PAGE_SIZE, "%d\n",
+	return scnprintf(buf, PAGE_SIZE, "%d\n",
 			pring ? pring->txq_max : 0);
 }
 
@@ -3544,7 +3548,7 @@ lpfc_txcmplq_hw_show(struct device *dev, struct device_attribute *attr,
 	struct lpfc_hba   *phba = ((struct lpfc_vport *) shost->hostdata)->phba;
 	struct lpfc_sli_ring *pring = lpfc_phba_elsring(phba);
 
-	return snprintf(buf, PAGE_SIZE, "%d\n",
+	return scnprintf(buf, PAGE_SIZE, "%d\n",
 			pring ? pring->txcmplq_max : 0);
 }
 
@@ -3580,7 +3584,7 @@ lpfc_nodev_tmo_show(struct device *dev, struct device_attribute *attr,
 	struct Scsi_Host  *shost = class_to_shost(dev);
 	struct lpfc_vport *vport = (struct lpfc_vport *) shost->hostdata;
 
-	return snprintf(buf, PAGE_SIZE, "%d\n",	vport->cfg_devloss_tmo);
+	return scnprintf(buf, PAGE_SIZE, "%d\n",	vport->cfg_devloss_tmo);
 }
 
 /**
@@ -5188,12 +5192,12 @@ lpfc_fcp_cpu_map_show(struct device *dev, struct device_attribute *attr,
 
 	switch (phba->cfg_fcp_cpu_map) {
 	case 0:
-		len += snprintf(buf + len, PAGE_SIZE-len,
+		len += scnprintf(buf + len, PAGE_SIZE-len,
 				"fcp_cpu_map: No mapping (%d)\n",
 				phba->cfg_fcp_cpu_map);
 		return len;
 	case 1:
-		len += snprintf(buf + len, PAGE_SIZE-len,
+		len += scnprintf(buf + len, PAGE_SIZE-len,
 				"fcp_cpu_map: HBA centric mapping (%d): "
 				"%d of %d CPUs online from %d possible CPUs\n",
 				phba->cfg_fcp_cpu_map, num_online_cpus(),
@@ -5207,12 +5211,12 @@ lpfc_fcp_cpu_map_show(struct device *dev, struct device_attribute *attr,
 		cpup = &phba->sli4_hba.cpu_map[phba->sli4_hba.curr_disp_cpu];
 
 		if (!cpu_present(phba->sli4_hba.curr_disp_cpu))
-			len += snprintf(buf + len, PAGE_SIZE - len,
+			len += scnprintf(buf + len, PAGE_SIZE - len,
 					"CPU %02d not present\n",
 					phba->sli4_hba.curr_disp_cpu);
 		else if (cpup->irq == LPFC_VECTOR_MAP_EMPTY) {
 			if (cpup->hdwq == LPFC_VECTOR_MAP_EMPTY)
-				len += snprintf(
+				len += scnprintf(
 					buf + len, PAGE_SIZE - len,
 					"CPU %02d hdwq None "
 					"physid %d coreid %d ht %d\n",
@@ -5220,7 +5224,7 @@ lpfc_fcp_cpu_map_show(struct device *dev, struct device_attribute *attr,
 					cpup->phys_id,
 					cpup->core_id, cpup->hyper);
 			else
-				len += snprintf(
+				len += scnprintf(
 					buf + len, PAGE_SIZE - len,
 					"CPU %02d EQ %04d hdwq %04d "
 					"physid %d coreid %d ht %d\n",
@@ -5229,7 +5233,7 @@ lpfc_fcp_cpu_map_show(struct device *dev, struct device_attribute *attr,
 					cpup->core_id, cpup->hyper);
 		} else {
 			if (cpup->hdwq == LPFC_VECTOR_MAP_EMPTY)
-				len += snprintf(
+				len += scnprintf(
 					buf + len, PAGE_SIZE - len,
 					"CPU %02d hdwq None "
 					"physid %d coreid %d ht %d IRQ %d\n",
@@ -5237,7 +5241,7 @@ lpfc_fcp_cpu_map_show(struct device *dev, struct device_attribute *attr,
 					cpup->phys_id,
 					cpup->core_id, cpup->hyper, cpup->irq);
 			else
-				len += snprintf(
+				len += scnprintf(
 					buf + len, PAGE_SIZE - len,
 					"CPU %02d EQ %04d hdwq %04d "
 					"physid %d coreid %d ht %d IRQ %d\n",
@@ -5252,7 +5256,7 @@ lpfc_fcp_cpu_map_show(struct device *dev, struct device_attribute *attr,
 		if (phba->sli4_hba.curr_disp_cpu <
 				phba->sli4_hba.num_possible_cpu &&
 				(len >= (PAGE_SIZE - 64))) {
-			len += snprintf(buf + len,
+			len += scnprintf(buf + len,
 					PAGE_SIZE - len, "more...\n");
 			break;
 		}
@@ -5772,10 +5776,10 @@ lpfc_sg_seg_cnt_show(struct device *dev, struct device_attribute *attr,
 	struct lpfc_hba   *phba = vport->phba;
 	int len;
 
-	len = snprintf(buf, PAGE_SIZE, "SGL sz: %d  total SGEs: %d\n",
+	len = scnprintf(buf, PAGE_SIZE, "SGL sz: %d  total SGEs: %d\n",
 		       phba->cfg_sg_dma_buf_size, phba->cfg_total_seg_cnt);
 
-	len += snprintf(buf + len, PAGE_SIZE, "Cfg: %d  SCSI: %d  NVME: %d\n",
+	len += scnprintf(buf + len, PAGE_SIZE, "Cfg: %d  SCSI: %d  NVME: %d\n",
 			phba->cfg_sg_seg_cnt, phba->cfg_scsi_seg_cnt,
 			phba->cfg_nvme_seg_cnt);
 	return len;
@@ -6774,7 +6778,7 @@ lpfc_show_rport_##field (struct device *dev,				\
 {									\
 	struct fc_rport *rport = transport_class_to_rport(dev);		\
 	struct lpfc_rport_data *rdata = rport->hostdata;		\
-	return snprintf(buf, sz, format_string,				\
+	return scnprintf(buf, sz, format_string,			\
 		(rdata->target) ? cast rdata->target->field : 0);	\
 }