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authorXi Wang <xi.wang@gmail.com>2012-02-14 05:18:48 -0500
committerTakashi Iwai <tiwai@suse.de>2012-02-15 14:58:15 +0100
commit8866f405efd4171f9d9c91901d2dd02f01bacb60 (patch)
tree414b07ed6d979f9aad804dc16b4f280247741eaf /sound/usb/quirks.c
parent27c3afe6e1cf129faac90405121203962da08ff4 (diff)
downloadlinux-8866f405efd4171f9d9c91901d2dd02f01bacb60.tar.gz
ALSA: usb-audio: avoid integer overflow in create_fixed_stream_quirk()
A malicious USB device could feed in a large nr_rates value.  This would
cause the subsequent call to kmemdup() to allocate a smaller buffer than
expected, leading to out-of-bounds access.

This patch validates the nr_rates value and reuses the limit introduced
in commit 4fa0e81b ("ALSA: usb-audio: fix possible hang and overflow
in parse_uac2_sample_rate_range()").

Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb/quirks.c')
-rw-r--r--sound/usb/quirks.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index a3ddac0deffd..27817266867a 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -132,10 +132,14 @@ static int create_fixed_stream_quirk(struct snd_usb_audio *chip,
 	unsigned *rate_table = NULL;
 
 	fp = kmemdup(quirk->data, sizeof(*fp), GFP_KERNEL);
-	if (! fp) {
+	if (!fp) {
 		snd_printk(KERN_ERR "cannot memdup\n");
 		return -ENOMEM;
 	}
+	if (fp->nr_rates > MAX_NR_RATES) {
+		kfree(fp);
+		return -EINVAL;
+	}
 	if (fp->nr_rates > 0) {
 		rate_table = kmemdup(fp->rate_table,
 				     sizeof(int) * fp->nr_rates, GFP_KERNEL);