ALSA: hwdep: prevent a harmless shift wrapping bug

The "info.index" variable represents a bit in hw->dsp_loaded which is
an unsigned int.  If it's higher than 31 we hit a shift wrapping bug.
This seems harmless, but I wanted to silence the static checker warning.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/core/hwdep.c b/sound/core/hwdep.c
index a73baa1..8faae3d 100644 (file)
--- a/sound/core/hwdep.c
+++ b/sound/core/hwdep.c
@@ -228,6 +228,8 @@ static int snd_hwdep_dsp_load(struct snd_hwdep *hw,
        memset(&info, 0, sizeof(info));
        if (copy_from_user(&info, _info, sizeof(info)))
                return -EFAULT;
+       if (info.index >= 32)
+               return -EINVAL;
        /* check whether the dsp was already loaded */
        if (hw->dsp_loaded & (1 << info.index))
                return -EBUSY;