selinux: declare data arrays const

The arrays for the policy capability names, the initial sid identifiers
and the class and permission names are not changed at runtime.  Declare
them const to avoid accidental modification.

Do not override the classmap and the initial sid list in the build time
script genheaders.

Check flose(3) is successful in genheaders.c, otherwise the written data
might be corrupted or incomplete.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
[PM: manual merge due to fuzz, minor style tweaks]
Signed-off-by: Paul Moore <paul@paul-moore.com>

2 files changed, 47 insertions, 32 deletions

diff --git a/scripts/selinux/genheaders/genheaders.c b/scripts/selinux/genheaders/genheaders.c
index f355b3e0e968..15520806889e 100644
--- a/scripts/selinux/genheaders/genheaders.c
+++ b/scripts/selinux/genheaders/genheaders.c
@@ -59,35 +59,27 @@ int main(int argc, char *argv[])
 		exit(2);
 	}
 
-	for (i = 0; secclass_map[i].name; i++) {
-		struct security_class_mapping *map = &secclass_map[i];
-		map->name = stoupperx(map->name);
-		for (j = 0; map->perms[j]; j++)
-			map->perms[j] = stoupperx(map->perms[j]);
-	}
-
-	isids_len = sizeof(initial_sid_to_string) / sizeof (char *);
-	for (i = 1; i < isids_len; i++) {
-		const char *s = initial_sid_to_string[i];
-
-		if (s)
-			initial_sid_to_string[i] = stoupperx(s);
-	}
-
 	fprintf(fout, "/* This file is automatically generated.  Do not edit. */\n");
 	fprintf(fout, "#ifndef _SELINUX_FLASK_H_\n#define _SELINUX_FLASK_H_\n\n");
 
 	for (i = 0; secclass_map[i].name; i++) {
-		struct security_class_mapping *map = &secclass_map[i];
-		fprintf(fout, "#define SECCLASS_%-39s %2d\n", map->name, i+1);
+		char *name = stoupperx(secclass_map[i].name);
+
+		fprintf(fout, "#define SECCLASS_%-39s %2d\n", name, i+1);
+		free(name);
 	}
 
 	fprintf(fout, "\n");
 
+	isids_len = sizeof(initial_sid_to_string) / sizeof(char *);
 	for (i = 1; i < isids_len; i++) {
 		const char *s = initial_sid_to_string[i];
-		if (s)
-			fprintf(fout, "#define SECINITSID_%-39s %2d\n", s, i);
+		if (s) {
+			char *sidname = stoupperx(s);
+
+			fprintf(fout, "#define SECINITSID_%-39s %2d\n", sidname, i);
+			free(sidname);
+		}
 	}
 	fprintf(fout, "\n#define SECINITSID_NUM %d\n", i-1);
 	fprintf(fout, "\nstatic inline bool security_is_socket_class(u16 kern_tclass)\n");
@@ -96,10 +88,14 @@ int main(int argc, char *argv[])
 	fprintf(fout, "\tswitch (kern_tclass) {\n");
 	for (i = 0; secclass_map[i].name; i++) {
 		static char s[] = "SOCKET";
-		struct security_class_mapping *map = &secclass_map[i];
-		int len = strlen(map->name), l = sizeof(s) - 1;
-		if (len >= l && memcmp(map->name + len - l, s, l) == 0)
-			fprintf(fout, "\tcase SECCLASS_%s:\n", map->name);
+		int len, l;
+		char *name = stoupperx(secclass_map[i].name);
+
+		len = strlen(name);
+		l = sizeof(s) - 1;
+		if (len >= l && memcmp(name + len - l, s, l) == 0)
+			fprintf(fout, "\tcase SECCLASS_%s:\n", name);
+		free(name);
 	}
 	fprintf(fout, "\t\tsock = true;\n");
 	fprintf(fout, "\t\tbreak;\n");
@@ -110,33 +106,52 @@ int main(int argc, char *argv[])
 	fprintf(fout, "}\n");
 
 	fprintf(fout, "\n#endif\n");
-	fclose(fout);
+
+	if (fclose(fout) != 0) {
+		fprintf(stderr, "Could not successfully close %s:  %s\n",
+			argv[1], strerror(errno));
+		exit(4);
+	}
 
 	fout = fopen(argv[2], "w");
 	if (!fout) {
 		fprintf(stderr, "Could not open %s for writing:  %s\n",
 			argv[2], strerror(errno));
-		exit(4);
+		exit(5);
 	}
 
 	fprintf(fout, "/* This file is automatically generated.  Do not edit. */\n");
 	fprintf(fout, "#ifndef _SELINUX_AV_PERMISSIONS_H_\n#define _SELINUX_AV_PERMISSIONS_H_\n\n");
 
 	for (i = 0; secclass_map[i].name; i++) {
-		struct security_class_mapping *map = &secclass_map[i];
-		int len = strlen(map->name);
+		const struct security_class_mapping *map = &secclass_map[i];
+		int len;
+		char *name = stoupperx(map->name);
+
+		len = strlen(name);
 		for (j = 0; map->perms[j]; j++) {
+			char *permname;
+
 			if (j >= 32) {
 				fprintf(stderr, "Too many permissions to fit into an access vector at (%s, %s).\n",
 					map->name, map->perms[j]);
 				exit(5);
 			}
-			fprintf(fout, "#define %s__%-*s 0x%08xU\n", map->name,
-				39-len, map->perms[j], 1U<<j);
+			permname = stoupperx(map->perms[j]);
+			fprintf(fout, "#define %s__%-*s 0x%08xU\n", name,
+				39-len, permname, 1U<<j);
+			free(permname);
 		}
+		free(name);
 	}
 
 	fprintf(fout, "\n#endif\n");
-	fclose(fout);
+
+	if (fclose(fout) != 0) {
+		fprintf(stderr, "Could not successfully close %s:  %s\n",
+			argv[2], strerror(errno));
+		exit(6);
+	}
+
 	exit(0);
 }
diff --git a/scripts/selinux/mdp/mdp.c b/scripts/selinux/mdp/mdp.c
index 105c1c31a316..1415604c3d24 100644
--- a/scripts/selinux/mdp/mdp.c
+++ b/scripts/selinux/mdp/mdp.c
@@ -82,7 +82,7 @@ int main(int argc, char *argv[])
 
 	/* print out the class permissions */
 	for (i = 0; secclass_map[i].name; i++) {
-		struct security_class_mapping *map = &secclass_map[i];
+		const struct security_class_mapping *map = &secclass_map[i];
 		fprintf(fout, "class %s\n", map->name);
 		fprintf(fout, "{\n");
 		for (j = 0; map->perms[j]; j++)
@@ -103,7 +103,7 @@ int main(int argc, char *argv[])
 #define SYSTEMLOW "s0"
 #define SYSTEMHIGH "s1:c0.c1"
 		for (i = 0; secclass_map[i].name; i++) {
-			struct security_class_mapping *map = &secclass_map[i];
+			const struct security_class_mapping *map = &secclass_map[i];
 
 			fprintf(fout, "mlsconstrain %s {\n", map->name);
 			for (j = 0; map->perms[j]; j++)