From fd0484aba8e51d16af1e3a880f9b8b857b385eb3 Mon Sep 17 00:00:00 2001
From: Erik de Castro Lopo <erikd@mega-nerd.com>
Date: Wed, 12 Apr 2017 19:45:30 +1000
Subject: [PATCH] FLAC: Fix a buffer read overrun
Buffer read overrun occurs when reading a FLAC file that switches
from 2 channels to one channel mid-stream. Only option is to
abort the read.
Closes: https://github.com/erikd/libsndfile/issues/230
---
src/common.h | 1 +
src/flac.c | 13 +++++++++++++
src/sndfile.c | 1 +
3 files changed, 15 insertions(+)
diff --git a/src/common.h b/src/common.h
index 0bd810c3..e2669b6a 100644
--- a/src/common.h
+++ b/src/common.h
@@ -725,6 +725,7 @@ enum
SFE_FLAC_INIT_DECODER,
SFE_FLAC_LOST_SYNC,
SFE_FLAC_BAD_SAMPLE_RATE,
+ SFE_FLAC_CHANNEL_COUNT_CHANGED,
SFE_FLAC_UNKOWN_ERROR,
SFE_WVE_NOT_WVE,
diff --git a/src/flac.c b/src/flac.c
index 84de0e26..986a7b8f 100644
--- a/src/flac.c
+++ b/src/flac.c
@@ -434,6 +434,19 @@ sf_flac_meta_callback (const FLAC__StreamDecoder * UNUSED (decoder), const FLAC_
switch (metadata->type)
{ case FLAC__METADATA_TYPE_STREAMINFO :
+ if (psf->sf.channels > 0 && psf->sf.channels != (int) metadata->data.stream_info.channels)
+ { psf_log_printf (psf, "Error: FLAC stream changed from %d to %d channels\n"
+ "Nothing to be but to error out.\n" ,
+ psf->sf.channels, metadata->data.stream_info.channels) ;
+ psf->error = SFE_FLAC_CHANNEL_COUNT_CHANGED ;
+ return ;
+ } ;
+
+ if (psf->sf.channels > 0 && psf->sf.samplerate != (int) metadata->data.stream_info.sample_rate)
+ { psf_log_printf (psf, "Warning: FLAC stream changed sample rates from %d to %d.\n"
+ "Carrying on as if nothing happened.",
+ psf->sf.samplerate, metadata->data.stream_info.sample_rate) ;
+ } ;
psf->sf.channels = metadata->data.stream_info.channels ;
psf->sf.samplerate = metadata->data.stream_info.sample_rate ;
psf->sf.frames = metadata->data.stream_info.total_samples ;
diff --git a/src/sndfile.c b/src/sndfile.c
index 41875610..e2a87be8 100644
--- a/src/sndfile.c
+++ b/src/sndfile.c
@@ -245,6 +245,7 @@ ErrorStruct SndfileErrors [] =
{ SFE_FLAC_INIT_DECODER , "Error : problem with initialization of the flac decoder." },
{ SFE_FLAC_LOST_SYNC , "Error : flac decoder lost sync." },
{ SFE_FLAC_BAD_SAMPLE_RATE, "Error : flac does not support this sample rate." },
+ { SFE_FLAC_CHANNEL_COUNT_CHANGED, "Error : flac channel changed mid stream." },
{ SFE_FLAC_UNKOWN_ERROR , "Error : unknown error in flac decoder." },
{ SFE_WVE_NOT_WVE , "Error : not a WVE file." },