aboutsummaryrefslogtreecommitdiffstats
path: root/sound/usb/format.c
diff options
context:
space:
mode:
authorXi Wang <xi.wang@gmail.com>2012-02-14 05:18:48 -0500
committerTakashi Iwai <tiwai@suse.de>2012-02-15 08:58:15 -0500
commit8866f405efd4171f9d9c91901d2dd02f01bacb60 (patch)
tree414b07ed6d979f9aad804dc16b4f280247741eaf /sound/usb/format.c
parent27c3afe6e1cf129faac90405121203962da08ff4 (diff)
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/format.c')
-rw-r--r--sound/usb/format.c4
1 files changed, 1 insertions, 3 deletions
diff --git a/sound/usb/format.c b/sound/usb/format.c
index e09aba19375c..ddfef57c4c9f 100644
--- a/sound/usb/format.c
+++ b/sound/usb/format.c
@@ -209,8 +209,6 @@ static int parse_audio_format_rates_v1(struct snd_usb_audio *chip, struct audiof
209 return 0; 209 return 0;
210} 210}
211 211
212#define MAX_UAC2_NR_RATES 1024
213
214/* 212/*
215 * Helper function to walk the array of sample rate triplets reported by 213 * Helper function to walk the array of sample rate triplets reported by
216 * the device. The problem is that we need to parse whole array first to 214 * the device. The problem is that we need to parse whole array first to
@@ -255,7 +253,7 @@ static int parse_uac2_sample_rate_range(struct audioformat *fp, int nr_triplets,
255 fp->rates |= snd_pcm_rate_to_rate_bit(rate); 253 fp->rates |= snd_pcm_rate_to_rate_bit(rate);
256 254
257 nr_rates++; 255 nr_rates++;
258 if (nr_rates >= MAX_UAC2_NR_RATES) { 256 if (nr_rates >= MAX_NR_RATES) {
259 snd_printk(KERN_ERR "invalid uac2 rates\n"); 257 snd_printk(KERN_ERR "invalid uac2 rates\n");
260 break; 258 break;
261 } 259 }