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 d276e33880be1e632a95f5a960e4c0eab6c7f983..2a1d1ae5c11d454f57f957d02ed0904d41af3d30 100644 (file)
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -1086,6 +1086,9 @@ _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;