ALSA: wavefront: Fix integer overflow in sample size validation

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: 1da177e4c3f4 ("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>

diff --git a/sound/isa/wavefront/wavefront_synth.c b/sound/isa/wavefront/wavefront_synth.c
index cd5c177943aa0d77c6177c21049d7d0cd301661e..0d78533e1cfd6b474f2d01d501f87b13a03b070d 100644 (file)
--- a/sound/isa/wavefront/wavefront_synth.c
+++ b/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;
                }