mcstrans: fix memory leaks reported by clang's static analyzer

There are many memory leaks in mcstrans. Clean them up in order to
reduce the noise in clang's static analyzer report. Some are remaining,
because they are more complex to fix.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>

mcstrans/src/mcstrans.c

@@ -708,6 +708,7 @@ append(affix_t **affixes, const char *val) {
 
 err:
 	log_error("allocation error %s", strerror(errno));
+	free(affix);
 	return -1;
 }
 
@@ -1517,21 +1518,26 @@ trans_context(const security_context_t incon, security_context_t *rcon) {
 		} else {
 			trans = compute_trans_from_raw(range, domain);
 			if (trans)
-				if (add_cache(domain, range, trans) < 0)
+				if (add_cache(domain, range, trans) < 0) {
+					free(range);
 					return -1;
+				}
 		}
 
 		if (lrange && urange) {
 			ltrans = find_in_hashtable(lrange, domain, domain->raw_to_trans);
 			if (! ltrans) {
 				ltrans = compute_trans_from_raw(lrange, domain);
 				if (ltrans) {
-					if (add_cache(domain, lrange, ltrans) < 0)
+					if (add_cache(domain, lrange, ltrans) < 0) {
+						free(range);
 						return -1;
+					}
 				} else {
 					ltrans = strdup(lrange);
 					if (! ltrans) {
 						log_error("strdup failed %s", strerror(errno));
+						free(range);
 						return -1;
 					}
 				}
@@ -1541,25 +1547,36 @@ trans_context(const security_context_t incon, security_context_t *rcon) {
 			if (! utrans) {
 				utrans = compute_trans_from_raw(urange, domain);
 				if (utrans) {
-					if (add_cache(domain, urange, utrans) < 0)
+					if (add_cache(domain, urange, utrans) < 0) {
+						free(ltrans);
+						free(range);
 						return -1;
+					}
 				} else {
 					utrans = strdup(urange);
 					if (! utrans) {
 						log_error("strdup failed %s", strerror(errno));
- 						return -1;
- 					}
- 				}
+						free(ltrans);
+						free(range);
+						return -1;
+					}
+				}
 			}
 
 			if (strcmp(ltrans, utrans) == 0) {
 				if (asprintf(&trans, "%s", ltrans) < 0) {
 					log_error("asprintf failed %s", strerror(errno));
+					free(utrans);
+					free(ltrans);
+					free(range);
 					return -1;
 				}
 			} else {
 				if (asprintf(&trans, "%s-%s", ltrans, utrans) < 0) {
 					log_error("asprintf failed %s", strerror(errno));
+					free(utrans);
+					free(ltrans);
+					free(range);
 					return -1;
 				}
 			}
@@ -1629,13 +1646,17 @@ untrans_context(const security_context_t incon, security_context_t *rcon) {
 				if (!canonical) {
 					canonical = compute_trans_from_raw(raw, domain);
 					if (canonical && strcmp(canonical, range))
-						if (add_cache(domain, raw, canonical) < 0)
+						if (add_cache(domain, raw, canonical) < 0) {
+							free(range);
 							return -1;
+						}
 				}
 				if (canonical)
 					free(canonical);
-				if (add_cache(domain, raw, range) < 0)
+				if (add_cache(domain, raw, range) < 0) {
+					free(range);
 					return -1;
+				}
 			} else {
 				log_debug("untrans_context unable to compute raw context %s\n", range);
 			}
@@ -1650,17 +1671,24 @@ untrans_context(const security_context_t incon, security_context_t *rcon) {
 					if (!canonical) {
 						canonical = compute_trans_from_raw(lraw, domain);
 						if (canonical)
-							if (add_cache(domain, lraw, canonical) < 0)
+							if (add_cache(domain, lraw, canonical) < 0) {
+								free(lraw);
+								free(range);
 								return -1;
+							}
 					}
 					if (canonical)
 						free(canonical);
-					if (add_cache(domain, lraw, lrange) < 0)
+					if (add_cache(domain, lraw, lrange) < 0) {
+						free(lraw);
+						free(range);
 						return -1;
+					}
 				} else {
 					lraw = strdup(lrange);
 					if (! lraw) {
 						log_error("strdup failed %s", strerror(errno));
+						free(range);
 						return -1;
 					}
 				}
@@ -1674,17 +1702,27 @@ untrans_context(const security_context_t incon, security_context_t *rcon) {
 					if (!canonical) {
 						canonical = compute_trans_from_raw(uraw, domain);
 						if (canonical)
-							if (add_cache(domain, uraw, canonical) < 0)
+							if (add_cache(domain, uraw, canonical) < 0) {
+								free(uraw);
+								free(lraw);
+								free(range);
 								return -1;
 							}
+					}
 					if (canonical)
 						free(canonical);
-					if (add_cache(domain, uraw, urange) < 0)
+					if (add_cache(domain, uraw, urange) < 0) {
+						free(uraw);
+						free(lraw);
+						free(range);
 						return -1;
+					}
 				} else {
 					uraw = strdup(urange);
 					if (! uraw) {
 						log_error("strdup failed %s", strerror(errno));
+						free(lraw);
+						free(range);
 						return -1;
 					}
 				}
@@ -1694,11 +1732,17 @@ untrans_context(const security_context_t incon, security_context_t *rcon) {
 			if (strcmp(lraw, uraw) == 0) {
 				if (asprintf(&raw, "%s", lraw) < 0) {
 					log_error("asprintf failed %s", strerror(errno));
+					free(uraw);
+					free(lraw);
+					free(range);
 					return -1;
 				}
 			} else {
 				if (asprintf(&raw, "%s-%s", lraw, uraw) < 0) {
 					log_error("asprintf failed %s", strerror(errno));
+					free(uraw);
+					free(lraw);
+					free(range);
 					return -1;
 				}
 			}