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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 01e21037d8feb5c04e6aedee608e9cdedc0d87bd..00a5656765835d81b518aecbdfb9ebfe17ffc39a 100644 (file)
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -1021,6 +1021,9 @@ _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;