Doug / smarc-fsl-linux-kernel

Download as
Browse Code ยป

Commit 8866f405efd4171f9d9c91901d2dd02f01bacb60

Authored by Xi Wang
Committed by Takashi Iwai
1 parent 27c3afe6e1
Exists in smarc-l5.0.0_1.0.0-ga and in 5 other branches imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga

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>

Showing 3 changed files with 7 additions and 4 deletions Side-by-side Diff

1 1 #ifndef __USBAUDIO_CARD_H
2 2 #define __USBAUDIO_CARD_H
3 3  
  4 +#define MAX_NR_RATES 1024
4 5 #define MAX_PACKS 20
5 6 #define MAX_PACKS_HS (MAX_PACKS * 8) /* in high speed mode */
6 7 #define MAX_URBS 8
... ... @@ -209,8 +209,6 @@
209 209 return 0;
210 210 }
211 211  
212   -#define MAX_UAC2_NR_RATES 1024
213   -
214 212 /*
215 213 * Helper function to walk the array of sample rate triplets reported by
216 214 * the device. The problem is that we need to parse whole array first to
... ... @@ -255,7 +253,7 @@
255 253 fp->rates |= snd_pcm_rate_to_rate_bit(rate);
256 254  
257 255 nr_rates++;
258   - if (nr_rates >= MAX_UAC2_NR_RATES) {
  256 + if (nr_rates >= MAX_NR_RATES) {
259 257 snd_printk(KERN_ERR "invalid uac2 rates\n");
260 258 break;
261 259 }
... ... @@ -132,9 +132,13 @@
132 132 unsigned *rate_table = NULL;
133 133  
134 134 fp = kmemdup(quirk->data, sizeof(*fp), GFP_KERNEL);
135   - if (! fp) {
  135 + if (!fp) {
136 136 snd_printk(KERN_ERR "cannot memdup\n");
137 137 return -ENOMEM;
  138 + }
  139 + if (fp->nr_rates > MAX_NR_RATES) {
  140 + kfree(fp);
  141 + return -EINVAL;
138 142 }
139 143 if (fp->nr_rates > 0) {
140 144 rate_table = kmemdup(fp->rate_table,