[PATCH 6.12 0801/1102] ksmbd: prevent out-of-bounds reads in share config responses

@@ -88,9 +88,9 @@ static struct ksmbd_share_config *__share_lookup(const char *name)
 
 static int parse_veto_list(struct ksmbd_share_config *share,
 			   char *veto_list,
-			   int veto_list_sz)
+			   size_t veto_list_sz)
 {
-	int sz = 0;
+	size_t sz;
 
 	if (!veto_list_sz)
 		return 0;

@@ -98,7 +98,7 @@ static int parse_veto_list(struct ksmbd_share_config *share,
 	while (veto_list_sz > 0) {
 		struct ksmbd_veto_pattern *p;
 
-		sz = strlen(veto_list);
+		sz = strnlen(veto_list, veto_list_sz);
 		if (!sz)
 			break;
 

@@ -106,7 +106,7 @@ static int parse_veto_list(struct ksmbd_share_config *share,
 		if (!p)
 			return -ENOMEM;
 
-		p->pattern = kstrdup(veto_list, KSMBD_DEFAULT_GFP);
+		p->pattern = kstrndup(veto_list, sz, KSMBD_DEFAULT_GFP);
 		if (!p->pattern) {
 			kfree(p);
 			return -ENOMEM;

@@ -114,6 +114,9 @@ static int parse_veto_list(struct ksmbd_share_config *share,
 
 		list_add(&p->list, &share->veto_list);
 
+		if (sz == veto_list_sz)
+			break;
+
 		veto_list += sz + 1;
 		veto_list_sz -= (sz + 1);
 	}

@@ -165,13 +168,27 @@ static struct ksmbd_share_config *share_config_request(struct ksmbd_work *work,
 	}
 
 	if (!test_share_config_flag(share, KSMBD_SHARE_FLAG_PIPE)) {
-		int path_len = PATH_MAX;
+		size_t path_len;
 
-		if (resp->payload_sz)
+		if (resp->payload_sz <= resp->veto_list_sz) {
+			ret = -EINVAL;
+		} else {
 			path_len = resp->payload_sz - resp->veto_list_sz;
-
-		share->path = kstrndup(ksmbd_share_config_path(resp), path_len,
-				      KSMBD_DEFAULT_GFP);
+			if (resp->veto_list_sz)
+				path_len--;
+
+			if (!path_len) {
+				ret = -EINVAL;
+			} else {
+				share->path = kstrndup(
+					ksmbd_share_config_path(resp),
+					path_len, KSMBD_DEFAULT_GFP);
+				if (!share->path)
+					ret = -ENOMEM;
+				else
+					ret = 0;
+			}
+		}
 		if (share->path) {
 			share->path_sz = strlen(share->path);
 			while (share->path_sz > 1 &&

@@ -184,7 +201,8 @@ static struct ksmbd_share_config *share_config_request(struct ksmbd_work *work,
 		share->force_directory_mode = resp->force_directory_mode;
 		share->force_uid = resp->force_uid;
 		share->force_gid = resp->force_gid;
-		ret = parse_veto_list(share,
+		if (!ret)
+			ret = parse_veto_list(share,
 				      KSMBD_SHARE_CONFIG_VETO_LIST(resp),
 				      resp->veto_list_sz);
 		if (!ret && share->path) {

@@ -524,14 +524,21 @@ static int ipc_validate_msg(struct ipc_msg_table_entry *entry)
 		if (entry->msg_sz < sizeof(struct ksmbd_share_config_response))
 			return -EINVAL;
 
-		if (resp->payload_sz) {
-			if (resp->payload_sz < resp->veto_list_sz)
-				return -EINVAL;
+		if (strnlen(resp->share_name, sizeof(resp->share_name)) ==
+		    sizeof(resp->share_name))
+			return -EINVAL;
 
-			if (check_add_overflow(sizeof(struct ksmbd_share_config_response),
-					       resp->payload_sz, &msg_sz))
-				return -EINVAL;
-		}
+		if (resp->veto_list_sz > resp->payload_sz)
+			return -EINVAL;
+
+		if (resp->flags != KSMBD_SHARE_FLAG_INVALID &&
+		    !(resp->flags & KSMBD_SHARE_FLAG_PIPE) &&
+		    resp->payload_sz <= resp->veto_list_sz)
+			return -EINVAL;
+
+		if (check_add_overflow(sizeof(struct ksmbd_share_config_response),
+				       resp->payload_sz, &msg_sz))
+			return -EINVAL;
 		break;
 	}
 	case KSMBD_EVENT_LOGIN_REQUEST_EXT: