diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
index 9281191d7920..d54c866facce 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c
@@ -852,6 +852,26 @@ static void fw_abort_batch_reqs(struct firmware *fw)
 	mutex_unlock(&fw_lock);
 }
 
+/*
+ * Reject firmware file names with ".." path components.
+ * There are drivers that construct firmware file names from device-supplied
+ * strings, and we don't want some device to be able to tell us "I would like to
+ * be sent my firmware from ../../../etc/shadow, please".
+ *
+ * Search for ".." surrounded by either '/' or start/end of string.
+ *
+ * This intentionally only looks at the firmware name, not at the firmware base
+ * directory or at symlink contents.
+ */
+static bool name_contains_dotdot(const char *name)
+{
+	size_t name_len = strlen(name);
+
+	return strcmp(name, "..") == 0 || strncmp(name, "../", 3) == 0 ||
+	       strstr(name, "/../") != NULL ||
+	       (name_len >= 3 && strcmp(name+name_len-3, "/..") == 0);
+}
+
 /* called from request_firmware() and request_firmware_work_func() */
 static int
 _request_firmware(const struct firmware **firmware_p, const char *name,
@@ -872,6 +892,14 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
 		goto out;
 	}
 
+	if (name_contains_dotdot(name)) {
+		dev_warn(device,
+			 "Firmware load for '%s' refused, path contains '..' component\n",
+			 name);
+		ret = -EINVAL;
+		goto out;
+	}
+
 	ret = _request_firmware_prepare(&fw, name, device, buf, size,
 					offset, opt_flags);
 	if (ret <= 0) /* error or already assigned */
@@ -947,6 +975,8 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
  *      @name will be used as $FIRMWARE in the uevent environment and
  *      should be distinctive enough not to be confused with any other
  *      firmware image for this or any other device.
+ *	It must not contain any ".." path components - "foo/bar..bin" is
+ *	allowed, but "foo/../bar.bin" is not.
  *
  *	Caller must hold the reference count of @device.
  *