ALSA: wavefront: Fix integer overflow in sample size validation

commit 0c4a13b upstream.

The wavefront_send_sample() function has an integer overflow issue
when validating sample size. The header->size field is u32 but gets
cast to int for comparison with dev->freemem

Fix by using unsigned comparison to avoid integer overflow.

Fixes: 1da177e ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Junrui Luo <moonafterrain@outlook.com>
Link: https://patch.msgid.link/SYBPR01MB7881B47789D1B060CE8BF4C3AFC2A@SYBPR01MB7881.ausprd01.prod.outlook.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: avasummer

sound/isa/wavefront/wavefront_synth.c

@@ -950,9 +950,9 @@ wavefront_send_sample (snd_wavefront_t *dev,
 	if (header->size) {
 		dev->freemem = wavefront_freemem (dev);
 
-		if (dev->freemem < (int)header->size) {
+		if (dev->freemem < 0 || dev->freemem < header->size) {
 			dev_err(dev->card->dev,
-				"insufficient memory to load %d byte sample.\n",
+				"insufficient memory to load %u byte sample.\n",
 				header->size);
 			return -ENOMEM;
 		}