[PATCH 3.13 032/105] firmware_class: make sure fw requests contain a name

[Kamal Mostafa]

3.13.11.10 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Kees Cook <keescook at chromium.org>

commit 471b095dfe0d693a8d624cbc716d1ee4d74eb437 upstream.

An empty firmware request name will trigger warnings when building
device names. Make sure this is caught earlier and rejected.

The warning was visible via the test_firmware.ko module interface:

echo -ne "\x00" > /sys/devices/virtual/misc/test_firmware/trigger_request

Reported-by: Sasha Levin <sasha.levin at oracle.com>
Signed-off-by: Kees Cook <keescook at chromium.org>
Tested-by: Sasha Levin <sasha.levin at oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/base/firmware_class.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index e2b51f8..88c4812 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -1070,6 +1070,9 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
 	if (!firmware_p)
 		return -EINVAL;
 
+	if (!name || name[0] == '\0')
+		return -EINVAL;
+
 	ret = _request_firmware_prepare(&fw, name, device);
 	if (ret <= 0) /* error or already assigned */
 		goto out;
-- 
1.9.1