diff --git a/security/tomoyo/Kconfig b/security/tomoyo/Kconfig
index 404dce66952a..a00ab7eb6181 100644
--- a/security/tomoyo/Kconfig
+++ b/security/tomoyo/Kconfig
@@ -74,3 +74,13 @@ config SECURITY_TOMOYO_ACTIVATION_TRIGGER
 	  You can override this setting via TOMOYO_trigger= kernel command line
 	  option. For example, if you pass init=/bin/systemd option, you may
 	  want to also pass TOMOYO_trigger=/bin/systemd option.
+
+config SECURITY_TOMOYO_INSECURE_BUILTIN_SETTING
+	bool "Use insecure built-in settings for fuzzing tests."
+	default n
+	depends on SECURITY_TOMOYO
+	select SECURITY_TOMOYO_OMIT_USERSPACE_LOADER
+	help
+	  Enabling this option forces minimal built-in policy and disables
+	  domain/program checks for run-time policy modifications. Please enable
+	  this option only if this kernel is built for doing fuzzing tests.
diff --git a/security/tomoyo/common.c b/security/tomoyo/common.c
index 57988d95d33d..dd3d5942e669 100644
--- a/security/tomoyo/common.c
+++ b/security/tomoyo/common.c
@@ -940,7 +940,7 @@ static bool tomoyo_manager(void)
 	const char *exe;
 	const struct task_struct *task = current;
 	const struct tomoyo_path_info *domainname = tomoyo_domain()->domainname;
-	bool found = false;
+	bool found = IS_ENABLED(CONFIG_SECURITY_TOMOYO_INSECURE_BUILTIN_SETTING);
 
 	if (!tomoyo_policy_loaded)
 		return true;
@@ -2810,6 +2810,16 @@ void tomoyo_check_profile(void)
  */
 void __init tomoyo_load_builtin_policy(void)
 {
+#ifdef CONFIG_SECURITY_TOMOYO_INSECURE_BUILTIN_SETTING
+	static char tomoyo_builtin_profile[] __initdata =
+		"PROFILE_VERSION=20150505\n"
+		"0-CONFIG={ mode=learning grant_log=no reject_log=yes }\n";
+	static char tomoyo_builtin_exception_policy[] __initdata =
+		"aggregator proc:/self/exe /proc/self/exe\n";
+	static char tomoyo_builtin_domain_policy[] __initdata = "";
+	static char tomoyo_builtin_manager[] __initdata = "";
+	static char tomoyo_builtin_stat[] __initdata = "";
+#else
 	/*
 	 * This include file is manually created and contains built-in policy
 	 * named "tomoyo_builtin_profile", "tomoyo_builtin_exception_policy",
@@ -2817,6 +2827,7 @@ void __init tomoyo_load_builtin_policy(void)
 	 * "tomoyo_builtin_stat" in the form of "static char [] __initdata".
 	 */
 #include "builtin-policy.h"
+#endif
 	u8 i;
 	const int idx = tomoyo_read_lock();
 
diff --git a/security/tomoyo/network.c b/security/tomoyo/network.c
index 9094f4b3b367..f9ff121d7e1e 100644
--- a/security/tomoyo/network.c
+++ b/security/tomoyo/network.c
@@ -505,6 +505,8 @@ static int tomoyo_check_inet_address(const struct sockaddr *addr,
 {
 	struct tomoyo_inet_addr_info *i = &address->inet;
 
+	if (addr_len < offsetofend(struct sockaddr, sa_family))
+		return 0;
 	switch (addr->sa_family) {
 	case AF_INET6:
 		if (addr_len < SIN6_LEN_RFC2133)
@@ -594,6 +596,8 @@ static int tomoyo_check_unix_address(struct sockaddr *addr,
 {
 	struct tomoyo_unix_addr_info *u = &address->unix0;
 
+	if (addr_len < offsetofend(struct sockaddr, sa_family))
+		return 0;
 	if (addr->sa_family != AF_UNIX)
 		return 0;
 	u->addr = ((struct sockaddr_un *) addr)->sun_path;
diff --git a/security/tomoyo/realpath.c b/security/tomoyo/realpath.c
index 85e6e31dd1e5..e7832448d721 100644
--- a/security/tomoyo/realpath.c
+++ b/security/tomoyo/realpath.c
@@ -295,7 +295,8 @@ char *tomoyo_realpath_from_path(const struct path *path)
 		 * or dentry without vfsmount.
 		 */
 		if (!path->mnt ||
-		    (!inode->i_op->rename))
+		    (!inode->i_op->rename &&
+		     !(sb->s_type->fs_flags & FS_REQUIRES_DEV)))
 			pos = tomoyo_get_local_path(path->dentry, buf,
 						    buf_len - 1);
 		/* Get absolute name for the rest. */
diff --git a/security/tomoyo/util.c b/security/tomoyo/util.c
index 0517cbdd7275..52752e1a84ed 100644
--- a/security/tomoyo/util.c
+++ b/security/tomoyo/util.c
@@ -1076,8 +1076,10 @@ bool tomoyo_domain_quota_is_ok(struct tomoyo_request_info *r)
 		domain->flags[TOMOYO_DIF_QUOTA_WARNED] = true;
 		/* r->granted = false; */
 		tomoyo_write_log(r, "%s", tomoyo_dif[TOMOYO_DIF_QUOTA_WARNED]);
+#ifndef CONFIG_SECURITY_TOMOYO_INSECURE_BUILTIN_SETTING
 		pr_warn("WARNING: Domain '%s' has too many ACLs to hold. Stopped learning mode.\n",
 			domain->domainname->name);
+#endif
 	}
 	return false;
 }