fix memory leaks and uninitialized jump

Some error's were reported by valgrind (below) fix them. The test
cases on which these leaks were detected:

1. properly formed file_contexts file.
2. malformed file_contexts file, unknown type.
3. malformed file_contexts file, type that fails on validate callback.
4. malformed file_contexts file, invalid regex.
5. malformed file_contexts file, invalid mode.

==3819== Conditional jump or move depends on uninitialised value(s)
==3819==    at 0x12A682: closef (label_file.c:577)
==3819==    by 0x12A196: selabel_close (label.c:163)
==3819==    by 0x10A2FD: cleanup (checkfc.c:218)
==3819==    by 0x5089258: __run_exit_handlers (exit.c:82)
==3819==    by 0x50892A4: exit (exit.c:104)
==3819==    by 0x10A231: main (checkfc.c:361)
==3819==  Uninitialised value was created by a heap allocation
==3819==    at 0x4C2AB80: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==3819==    by 0x4C2CF1F: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==3819==    by 0x12BB31: process_file (label_file.h:273)
==3819==    by 0x12A2BA: selabel_file_init (label_file.c:522)
==3819==    by 0x12A0BB: selabel_open (label.c:88)
==3819==    by 0x10A038: main (checkfc.c:292)
==3819==
==3819==
==3819== HEAP SUMMARY:
==3819==     in use at exit: 729 bytes in 19 blocks
==3819==   total heap usage: 21,126 allocs, 21,107 frees, 923,854 bytes allocated
==3819==
==3819== 81 bytes in 1 blocks are definitely lost in loss record 1 of 2
==3819==    at 0x4C2AB80: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==3819==    by 0x50D5839: strdup (strdup.c:42)
==3819==    by 0x12A2A6: selabel_file_init (label_file.c:517)
==3819==    by 0x12A0BB: selabel_open (label.c:88)
==3819==    by 0x10A038: main (checkfc.c:292)
==3819==

==4238== 40 bytes in 1 blocks are definitely lost in loss record 1 of 6
==4238==    at 0x4C2AB80: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==4238==    by 0x12A1D2: selabel_file_init (label_file.c:886)
==4238==    by 0x12A0BB: selabel_open (label.c:88)
==4238==    by 0x10A038: main (checkfc.c:292)
==4238==
==4238== 81 bytes in 1 blocks are definitely lost in loss record 2 of 6
==4238==    at 0x4C2AB80: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==4238==    by 0x50D5839: strdup (strdup.c:42)
==4238==    by 0x12A2A6: selabel_file_init (label_file.c:517)
==4238==    by 0x12A0BB: selabel_open (label.c:88)
==4238==    by 0x10A038: main (checkfc.c:292)
==4238==
==4238== 386 bytes in 24 blocks are definitely lost in loss record 3 of 6
==4238==    at 0x4C2AB80: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==4238==    by 0x50D5889: strndup (strndup.c:45)
==4238==    by 0x12CDDF: read_spec_entries (label_support.c:37)
==4238==    by 0x12B72D: process_file (label_file.h:392)
==4238==    by 0x12A2BA: selabel_file_init (label_file.c:522)
==4238==    by 0x12A0BB: selabel_open (label.c:88)
==4238==    by 0x10A038: main (checkfc.c:292)
==4238==
==4238== 648 bytes in 18 blocks are definitely lost in loss record 4 of 6
==4238==    at 0x4C2CC70: calloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==4238==    by 0x117C9B: avtab_insert_node (avtab.c:105)
==4238==    by 0x117C10: avtab_insert (avtab.c:163)
==4238==    by 0x11880A: avtab_read_item (avtab.c:566)
==4238==    by 0x118BD3: avtab_read (avtab.c:600)
==4238==    by 0x125BDD: policydb_read (policydb.c:3854)
==4238==    by 0x109F87: main (checkfc.c:273)
==4238==
==4238== 1,095 bytes in 12 blocks are definitely lost in loss record 5 of 6
==4238==    at 0x4C2AB80: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==4238==    by 0x12D8D1: pcre_compile2 (pcre_compile.c:9217)
==4238==    by 0x12B239: compile_regex (label_file.h:357)
==4238==    by 0x12B9C7: process_file (label_file.h:429)
==4238==    by 0x12A2BA: selabel_file_init (label_file.c:522)
==4238==    by 0x12A0BB: selabel_open (label.c:88)
==4238==    by 0x10A038: main (checkfc.c:292)
==4238==
==4238== 1,296 bytes in 12 blocks are definitely lost in loss record 6 of 6
==4238==    at 0x4C2AB80: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==4238==    by 0x13EBE5: pcre_study (pcre_study.c:1565)
==4238==    by 0x12B25D: compile_regex (label_file.h:366)
==4238==    by 0x12B9C7: process_file (label_file.h:429)
==4238==    by 0x12A2BA: selabel_file_init (label_file.c:522)
==4238==    by 0x12A0BB: selabel_open (label.c:88)
==4238==    by 0x10A038: main (checkfc.c:292)

Change-Id: I2f7ed4ffbdcc3d0646f7caf66187d87347220c60
Signed-off-by: William Roberts <william.c.roberts@intel.com>

src/label.c

@@ -86,6 +86,7 @@ struct selabel_handle *selabel_open(unsigned int backend,
 	rec->validating = selabel_is_validate_set(opts, nopts);
 
 	if ((*initfuncs[backend])(rec, opts, nopts)) {
+		free(rec->spec_file);
 		free(rec);
 		rec = NULL;
 	}
@@ -161,6 +162,7 @@ enum selabel_cmp_result selabel_cmp(struct selabel_handle *h1,
 void selabel_close(struct selabel_handle *rec)
 {
 	rec->func_close(rec);
+	free(rec->spec_file);
 	free(rec);
 }
 

src/label_file.c

@@ -492,6 +492,8 @@ out:
 	return rc;
 }
 
+static void closef(struct selabel_handle *rec);
+
 static int init(struct selabel_handle *rec, const struct selinux_opt *opts,
 		unsigned n)
 {
@@ -543,7 +545,8 @@ static int init(struct selabel_handle *rec, const struct selinux_opt *opts,
 
 finish:
 	if (status)
-		free(data->spec_arr);
+		closef(rec);
+
 	return status;
 }
 

src/label_file.h

@@ -278,6 +278,7 @@ static inline int store_stem(struct saved_data *data, char *buf, int stem_len)
 	}
 	data->stem_arr[num].len = stem_len;
 	data->stem_arr[num].buf = buf;
+	data->stem_arr[num].from_mmap = 0;
 	data->num_stems++;
 
 	return num;
@@ -425,6 +426,18 @@ static inline int process_line(struct selabel_handle *rec,
 	/* process and store the specification in spec. */
 	spec_arr[nspec].stem_id = find_stem_from_spec(data, regex);
 	spec_arr[nspec].regex_str = regex;
+
+	spec_arr[nspec].type_str = type;
+	spec_arr[nspec].mode = 0;
+
+	spec_arr[nspec].lr.ctx_raw = context;
+
+	/*
+	 * bump data->nspecs to cause closef() to cover it in its free
+	 * but do not bump nspec since it's used below.
+	 */
+	data->nspec++;
+
 	if (rec->validating &&
 			    compile_regex(data, &spec_arr[nspec], &errbuf)) {
 		selinux_log(SELINUX_ERROR,
@@ -435,9 +448,6 @@ static inline int process_line(struct selabel_handle *rec,
 		return -1;
 	}
 
-	/* Convert the type string to a mode format */
-	spec_arr[nspec].type_str = type;
-	spec_arr[nspec].mode = 0;
 	if (type) {
 		mode_t mode = string_to_mode(type);
 
@@ -451,8 +461,6 @@ static inline int process_line(struct selabel_handle *rec,
 		spec_arr[nspec].mode = mode;
 	}
 
-	spec_arr[nspec].lr.ctx_raw = context;
-
 	/* Determine if specification has
 	 * any meta characters in the RE */
 	spec_hasMetaChars(&spec_arr[nspec]);
@@ -467,8 +475,6 @@ static inline int process_line(struct selabel_handle *rec,
 		}
 	}
 
-	data->nspec = ++nspec;
-
 	return 0;
 }