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>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 5401814c874df066833c8b5c3ac2dc28e2842490..b7a4fe586f8a34ee1f1157fdf1876160efd222ec 100644 (file)
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -588,6 +588,9 @@ request_firmware(const struct firmware **firmware_p, const char *name,
        struct firmware_priv *fw_priv;
        int ret;
 
+       if (!name || name[0] == '\0')
+               return -EINVAL;
+
        fw_priv = _request_firmware_prepare(firmware_p, name, device, true,
                                            false);
        if (IS_ERR_OR_NULL(fw_priv))