firmware_class: make sure fw requests contain a name

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@oracle.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 701212ba38b7fc8fb1568e44a5d0c789a4ed73fa..ec85b816fd5ac9b88ab3d61a806c0473bb890d02 100644 (file)
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -1063,6 +1063,9 @@ _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;