From c54147b3ada8c37a536a4df90e8707538021ed20 Mon Sep 17 00:00:00 2001
From: Chris Leech <[email protected]>
Date: Fri, 4 Feb 2022 09:21:47 -0800
Subject: [PATCH] fcoemon: add snprintf string precision modifiers in
 fcm_netif_advance

GCC 12 is warning of potential snprintf truncations

fcm_netif.ifname is an IFNAMSIZ array, but formating with %s doesn't
understand that, so add a precision modifier every time we print it to
limit the output.  This allows the compiler to verify that the output
buffer is of sufficient length to never truncate.

Signed-off-by: Chris Leech <[email protected]>

reference: https://github.com/morbidrsa/fcoe-utils/commit/c54147b3ada8c37a536a4df90e8707538021ed20
---
 fcoemon.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/fcoemon.c b/fcoemon.c
index 8c08bc5a032..b85f276c7df 100644
--- a/fcoemon.c
+++ b/fcoemon.c
@@ -3135,55 +3135,55 @@ static void fcm_netif_advance(struct fcm_netif *ff)
 	case FCD_ERROR:
 		break;
 	case FCD_GET_DCB_STATE:
-		snprintf(buf, sizeof(buf), "%c%x%2.2x%2.2x%2.2x%2.2x%s",
+		snprintf(buf, sizeof(buf), "%c%x%2.2x%2.2x%2.2x%2.2x%.*s",
 			 DCB_CMD, CLIF_RSP_VERSION,
 			 CMD_GET_CONFIG, FEATURE_DCB, 0,
-			 (u_int) strlen(ff->ifname), ff->ifname);
+			 (u_int) strlen(ff->ifname), IFNAMSIZ, ff->ifname);
 		ff->response_pending = fcm_dcbd_request(buf);
 		break;
 	case FCD_SEND_CONF:
 		snprintf(params, sizeof(params), "%x1%x02",
 			 ff->ff_app_info.enable,
 			 ff->ff_app_info.willing);
-		snprintf(buf, sizeof(buf), "%c%x%2.2x%2.2x%2.2x%2.2x%s%s",
+		snprintf(buf, sizeof(buf), "%c%x%2.2x%2.2x%2.2x%2.2x%.*s%s",
 			 DCB_CMD, CLIF_RSP_VERSION,
 			 CMD_SET_CONFIG, FEATURE_APP, APP_FCOE_STYPE,
-			 (u_int) strlen(ff->ifname), ff->ifname, params);
+			 (u_int) strlen(ff->ifname), IFNAMSIZ, ff->ifname, params);
 		ff->response_pending = fcm_dcbd_request(buf);
 		break;
 	case FCD_GET_PFC_CONFIG:
-		snprintf(buf, sizeof(buf), "%c%x%2.2x%2.2x%2.2x%2.2x%s%s",
+		snprintf(buf, sizeof(buf), "%c%x%2.2x%2.2x%2.2x%2.2x%.*s%s",
 			 DCB_CMD, CLIF_RSP_VERSION,
 			 CMD_GET_CONFIG, FEATURE_PFC, 0,
-			 (u_int) strlen(ff->ifname), ff->ifname, "");
+			 (u_int) strlen(ff->ifname), IFNAMSIZ, ff->ifname, "");
 		ff->response_pending = fcm_dcbd_request(buf);
 		break;
 	case FCD_GET_APP_CONFIG:
-		snprintf(buf, sizeof(buf), "%c%x%2.2x%2.2x%2.2x%2.2x%s%s",
+		snprintf(buf, sizeof(buf), "%c%x%2.2x%2.2x%2.2x%2.2x%.*s%s",
 			 DCB_CMD, CLIF_RSP_VERSION,
 			 CMD_GET_CONFIG, FEATURE_APP, APP_FCOE_STYPE,
-			 (u_int) strlen(ff->ifname), ff->ifname, "");
+			 (u_int) strlen(ff->ifname), IFNAMSIZ, ff->ifname, "");
 		ff->response_pending = fcm_dcbd_request(buf);
 		break;
 	case FCD_GET_PFC_OPER:
-		snprintf(buf, sizeof(buf), "%c%x%2.2x%2.2x%2.2x%2.2x%s%s",
+		snprintf(buf, sizeof(buf), "%c%x%2.2x%2.2x%2.2x%2.2x%.*s%s",
 			 DCB_CMD, CLIF_RSP_VERSION,
 			 CMD_GET_OPER, FEATURE_PFC, 0,
-			 (u_int) strlen(ff->ifname), ff->ifname, "");
+			 (u_int) strlen(ff->ifname), IFNAMSIZ, ff->ifname, "");
 		ff->response_pending = fcm_dcbd_request(buf);
 		break;
 	case FCD_GET_APP_OPER:
-		snprintf(buf, sizeof(buf), "%c%x%2.2x%2.2x%2.2x%2.2x%s%s",
+		snprintf(buf, sizeof(buf), "%c%x%2.2x%2.2x%2.2x%2.2x%.*s%s",
 			 DCB_CMD, CLIF_RSP_VERSION,
 			 CMD_GET_OPER, FEATURE_APP, APP_FCOE_STYPE,
-			 (u_int) strlen(ff->ifname), ff->ifname, "");
+			 (u_int) strlen(ff->ifname), IFNAMSIZ, ff->ifname, "");
 		ff->response_pending = fcm_dcbd_request(buf);
 		break;
 	case FCD_GET_PEER:
-		snprintf(buf, sizeof(buf), "%c%x%2.2x%2.2x%2.2x%2.2x%s%s",
+		snprintf(buf, sizeof(buf), "%c%x%2.2x%2.2x%2.2x%2.2x%.*s%s",
 			 DCB_CMD, CLIF_RSP_VERSION,
 			 CMD_GET_PEER, FEATURE_APP, APP_FCOE_STYPE,
-			 (u_int) strlen(ff->ifname), ff->ifname, "");
+			 (u_int) strlen(ff->ifname), IFNAMSIZ, ff->ifname, "");
 		ff->response_pending = fcm_dcbd_request(buf);
 		break;
 	case FCD_DONE:
-- 
2.39.1