ALSA: sound/pci/asihpi: check adapter index in hpi_ioctl

commit 4a122c10 upstream.

The user-supplied index into the adapters array needs to be checked, or
an out-of-bounds kernel pointer could be accessed and used, leading to
potentially exploitable memory corruption.
Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

sound/pci/asihpi/hpioctl.c

@@ -155,6 +155,11 @@ long asihpi_hpi_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		goto out;
 	}
 
+	if (hm->h.adapter_index >= HPI_MAX_ADAPTERS) {
+		err = -EINVAL;
+		goto out;
+	}
+
 	pa = &adapters[hm->h.adapter_index];
 	hr->h.size = 0;
 	if (hm->h.object == HPI_OBJ_SUBSYSTEM) {