usx2y: don't bother with access_ok() in ->dsp_load() (fc1c428e) · Commits · 戴 / test

memdup_user() checks it, so the only effect would be failing with -EINVAL instead of -EFAULT in case when access_ok() is false. However, the caller has already checked access_ok() itself (and would have buggered off with -EFAULT), so the check is completely pointless. Removing it both simplifies the only instance of ->dsp_load() and allows to get rid of the check in caller - its sole effect used to be in preventing a bogus error value from access_ok() in the instance. Let memdup_user() do the right thing instead... Signed-off-by:

Al Viro <viro@zeniv.linux.org.uk>

sound/usb/usx2y/usX2Yhwdep.c

+13 −15

Original line number	Diff line number	Diff line
		@@ -198,13 +198,12 @@ static int snd_usX2Y_hwdep_dsp_load(struct snd_hwdep *hw,
		struct snd_hwdep_dsp_image *dsp)
		{
		struct usX2Ydev *priv = hw->private_data;
		int lret, err = -EINVAL;
		snd_printdd( "dsp_load %s\n", dsp->name);

		if (access_ok(VERIFY_READ, dsp->image, dsp->length)) {
		struct usb_device* dev = priv->dev;
		int lret, err;
		char *buf;

		snd_printdd( "dsp_load %s\n", dsp->name);

		buf = memdup_user(dsp->image, dsp->length);
		if (IS_ERR(buf))
		return PTR_ERR(buf);
		@@ -215,7 +214,6 @@ static int snd_usX2Y_hwdep_dsp_load(struct snd_hwdep *hw,
		else
		err = usb_bulk_msg(dev, usb_sndbulkpipe(dev, 2), buf, dsp->length, &lret, 6000);
		kfree(buf);
		}
		if (err)
		return err;
		if (dsp->index == 1) {

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