From 515b986139183326cc40c67c75f83edc60826a9e Mon Sep 17 00:00:00 2001
From: Mans Rullgard <mans@mansr.com>
Date: Wed, 8 Nov 2017 00:27:46 +0000
Subject: [PATCH] adpcm: fix stack overflow with >4 channels (CVE-2017-15372)
---
src/adpcm.c | 8 +++++++-
src/adpcm.h | 3 +++
src/wav.c | 5 ++++-
3 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/src/adpcm.c b/src/adpcm.c
index 2e13867e..f64b7d5c 100644
--- a/src/adpcm.c
+++ b/src/adpcm.c
@@ -71,6 +71,11 @@ const short lsx_ms_adpcm_i_coef[7][2] = {
{ 392,-232}
};
+extern void *lsx_ms_adpcm_alloc(unsigned chans)
+{
+ return lsx_malloc(chans * sizeof(MsState_t));
+}
+
static inline sox_sample_t AdpcmDecode(sox_sample_t c, MsState_t *state,
sox_sample_t sample1, sox_sample_t sample2)
{
@@ -102,6 +107,7 @@ static inline sox_sample_t AdpcmDecode(sox_sample_t c, MsState_t *state,
/* lsx_ms_adpcm_block_expand_i() outputs interleaved samples into one output buffer */
const char *lsx_ms_adpcm_block_expand_i(
+ void *priv,
unsigned chans, /* total channels */
int nCoef,
const short *coef,
@@ -113,7 +119,7 @@ const char *lsx_ms_adpcm_block_expand_i(
const unsigned char *ip;
unsigned ch;
const char *errmsg = NULL;
- MsState_t state[4]; /* One decompressor state for each channel */
+ MsState_t *state = priv; /* One decompressor state for each channel */
/* Read the four-byte header for each channel */
ip = ibuff;
diff --git a/src/adpcm.h b/src/adpcm.h
index af4d6f08..db5cc615 100644
--- a/src/adpcm.h
+++ b/src/adpcm.h
@@ -29,8 +29,11 @@
/* default coef sets */
extern const short lsx_ms_adpcm_i_coef[7][2];
+extern void *lsx_ms_adpcm_alloc(unsigned chans);
+
/* lsx_ms_adpcm_block_expand_i() outputs interleaved samples into one output buffer */
extern const char *lsx_ms_adpcm_block_expand_i(
+ void *priv,
unsigned chans, /* total channels */
int nCoef,
const short *coef,
diff --git a/src/wav.c b/src/wav.c
index fad334cf..066be6d7 100644
--- a/src/wav.c
+++ b/src/wav.c
@@ -82,6 +82,7 @@ typedef struct {
/* following used by *ADPCM wav files */
unsigned short nCoefs; /* ADPCM: number of coef sets */
short *lsx_ms_adpcm_i_coefs; /* ADPCM: coef sets */
+ void *ms_adpcm_data; /* Private data of adpcm decoder */
unsigned char *packet; /* Temporary buffer for packets */
short *samples; /* interleaved samples buffer */
short *samplePtr; /* Pointer to current sample */
@@ -175,7 +176,7 @@ static unsigned short AdpcmReadBlock(sox_format_t * ft)
}
}
- errmsg = lsx_ms_adpcm_block_expand_i(ft->signal.channels, wav->nCoefs, wav->lsx_ms_adpcm_i_coefs, wav->packet, wav->samples, samplesThisBlock);
+ errmsg = lsx_ms_adpcm_block_expand_i(wav->ms_adpcm_data, ft->signal.channels, wav->nCoefs, wav->lsx_ms_adpcm_i_coefs, wav->packet, wav->samples, samplesThisBlock);
if (errmsg)
lsx_warn("%s", errmsg);
@@ -791,6 +792,7 @@ static int startread(sox_format_t * ft)
/* nCoefs, lsx_ms_adpcm_i_coefs used by adpcm.c */
wav->lsx_ms_adpcm_i_coefs = lsx_malloc(wav->nCoefs * 2 * sizeof(short));
+ wav->ms_adpcm_data = lsx_ms_adpcm_alloc(wChannels);
{
int i, errct=0;
for (i=0; len>=2 && i < 2*wav->nCoefs; i++) {
@@ -1216,6 +1218,7 @@ static int stopread(sox_format_t * ft)
free(wav->packet);
free(wav->samples);
free(wav->lsx_ms_adpcm_i_coefs);
+ free(wav->ms_adpcm_data);
free(wav->comment);
wav->comment = NULL;
--
2.25.0
