diff --git a/libselinux/src/avc_sidtab.c b/libselinux/src/avc_sidtab.c
index 9669264..a46cfa7 100644
--- a/libselinux/src/avc_sidtab.c
+++ b/libselinux/src/avc_sidtab.c
@@ -81,6 +81,11 @@ sidtab_context_to_sid(struct sidtab *s,
 	int hvalue, rc = 0;
 	struct sidtab_node *cur;
 
+	if (! ctx) {
+		errno = EINVAL;
+		return -1;
+	}
+
 	*sid = NULL;
 	hvalue = sidtab_hash(ctx);
 
diff --git a/libselinux/src/canonicalize_context.c b/libselinux/src/canonicalize_context.c
index 7cf3139..9d8dc86 100644
--- a/libselinux/src/canonicalize_context.c
+++ b/libselinux/src/canonicalize_context.c
@@ -17,6 +17,11 @@ int security_canonicalize_context_raw(const char * con,
 	size_t size;
 	int fd, ret;
 
+	if (! con) {
+		errno = EINVAL;
+		return -1;
+	}
+
 	if (!selinux_mnt) {
 		errno = ENOENT;
 		return -1;
diff --git a/libselinux/src/check_context.c b/libselinux/src/check_context.c
index 52063fa..9637dd7 100644
--- a/libselinux/src/check_context.c
+++ b/libselinux/src/check_context.c
@@ -14,6 +14,11 @@ int security_check_context_raw(const char * con)
 	char path[PATH_MAX];
 	int fd, ret;
 
+	if (! con) {
+		errno = EINVAL;
+		return -1;
+	}
+
 	if (!selinux_mnt) {
 		errno = ENOENT;
 		return -1;
diff --git a/libselinux/src/compute_av.c b/libselinux/src/compute_av.c
index 937e5c3..e67b3d3 100644
--- a/libselinux/src/compute_av.c
+++ b/libselinux/src/compute_av.c
@@ -26,6 +26,11 @@ int security_compute_av_flags_raw(const char * scon,
 		return -1;
 	}
 
+	if ((! scon) || (! tcon)) {
+		errno = EINVAL;
+		return -1;
+	}
+
 	snprintf(path, sizeof path, "%s/access", selinux_mnt);
 	fd = open(path, O_RDWR);
 	if (fd < 0)
diff --git a/libselinux/src/compute_create.c b/libselinux/src/compute_create.c
index 9559d42..7de721a 100644
--- a/libselinux/src/compute_create.c
+++ b/libselinux/src/compute_create.c
@@ -64,6 +64,11 @@ int security_compute_create_name_raw(const char * scon,
 		return -1;
 	}
 
+	if ((! scon) || (! tcon)) {
+		errno = EINVAL;
+		return -1;
+	}
+
 	snprintf(path, sizeof path, "%s/create", selinux_mnt);
 	fd = open(path, O_RDWR);
 	if (fd < 0)
diff --git a/libselinux/src/compute_member.c b/libselinux/src/compute_member.c
index 1fc7e41..4ff2173 100644
--- a/libselinux/src/compute_member.c
+++ b/libselinux/src/compute_member.c
@@ -25,6 +25,11 @@ int security_compute_member_raw(const char * scon,
 		return -1;
 	}
 
+	if ((! scon) || (! tcon)) {
+		errno = EINVAL;
+		return -1;
+	}
+
 	snprintf(path, sizeof path, "%s/member", selinux_mnt);
 	fd = open(path, O_RDWR);
 	if (fd < 0)
diff --git a/libselinux/src/compute_relabel.c b/libselinux/src/compute_relabel.c
index 4615aee..6a37acf 100644
--- a/libselinux/src/compute_relabel.c
+++ b/libselinux/src/compute_relabel.c
@@ -25,6 +25,11 @@ int security_compute_relabel_raw(const char * scon,
 		return -1;
 	}
 
+	if ((! scon) || (! tcon)) {
+		errno = EINVAL;
+		return -1;
+	}
+
 	snprintf(path, sizeof path, "%s/relabel", selinux_mnt);
 	fd = open(path, O_RDWR);
 	if (fd < 0)
diff --git a/libselinux/src/compute_user.c b/libselinux/src/compute_user.c
index b37c5d3..3737c28 100644
--- a/libselinux/src/compute_user.c
+++ b/libselinux/src/compute_user.c
@@ -24,6 +24,11 @@ int security_compute_user_raw(const char * scon,
 		return -1;
 	}
 
+	if (! scon) {
+		errno = EINVAL;
+		return -1;
+	}
+
 	snprintf(path, sizeof path, "%s/user", selinux_mnt);
 	fd = open(path, O_RDWR);
 	if (fd < 0)
diff --git a/libselinux/src/fsetfilecon.c b/libselinux/src/fsetfilecon.c
index 52707d0..83c138e 100644
--- a/libselinux/src/fsetfilecon.c
+++ b/libselinux/src/fsetfilecon.c
@@ -9,8 +9,12 @@
 
 int fsetfilecon_raw(int fd, const char * context)
 {
-	int rc = fsetxattr(fd, XATTR_NAME_SELINUX, context, strlen(context) + 1,
-			 0);
+	int rc;
+	if (! context) {
+		errno = EINVAL;
+		return -1;
+	}
+	rc = fsetxattr(fd, XATTR_NAME_SELINUX, context, strlen(context) + 1, 0);
 	if (rc < 0 && errno == ENOTSUP) {
 		char * ccontext = NULL;
 		int err = errno;
diff --git a/libselinux/src/lsetfilecon.c b/libselinux/src/lsetfilecon.c
index 1d3b28a..278e42a 100644
--- a/libselinux/src/lsetfilecon.c
+++ b/libselinux/src/lsetfilecon.c
@@ -9,8 +9,13 @@
 
 int lsetfilecon_raw(const char *path, const char * context)
 {
-	int rc = lsetxattr(path, XATTR_NAME_SELINUX, context, strlen(context) + 1,
-			 0);
+	int rc;
+	if (! context) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	rc = lsetxattr(path, XATTR_NAME_SELINUX, context, strlen(context) + 1, 0);
 	if (rc < 0 && errno == ENOTSUP) {
 		char * ccontext = NULL;
 		int err = errno;
diff --git a/libselinux/src/setfilecon.c b/libselinux/src/setfilecon.c
index d05969c..dddce3c 100644
--- a/libselinux/src/setfilecon.c
+++ b/libselinux/src/setfilecon.c
@@ -9,8 +9,12 @@
 
 int setfilecon_raw(const char *path, const char * context)
 {
-	int rc = setxattr(path, XATTR_NAME_SELINUX, context, strlen(context) + 1,
-			0);
+	int rc;
+	if (! context) {
+		errno = EINVAL;
+		return -1;
+	}
+	rc = setxattr(path, XATTR_NAME_SELINUX, context, strlen(context) + 1, 0);
 	if (rc < 0 && errno == ENOTSUP) {
 		char * ccontext = NULL;
 		int err = errno;
