From 2d54514a4f6437b67829717c05472d2e3300a258 Mon Sep 17 00:00:00 2001
From: Fabian Greffrath <fabian@greffrath.com>
Date: Wed, 27 Sep 2017 14:46:17 +0200
Subject: [PATCH] sfe_copy_data_fp: check value of "max" variable for being
 normal

and check elements of the data[] array for being finite.

Both checks use functions provided by the <math.h> header as declared
by the C99 standard.

Fixes #317
CVE-2017-14245
CVE-2017-14246
---
 programs/common.c          | 20 ++++++++++++++++----
 programs/common.h          |  2 +-
 programs/sndfile-convert.c |  6 +++++-
 3 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/programs/common.c b/programs/common.c
index a21e62ca..a249a585 100644
--- a/programs/common.c
+++ b/programs/common.c
@@ -36,6 +36,7 @@
 #include <string.h>
 #include <ctype.h>
 #include <stdint.h>
+#include <math.h>
 
 #include <sndfile.h>
 
@@ -45,7 +46,7 @@
 
 #define	MIN(x, y)	((x) < (y) ? (x) : (y))
 
-void
+int
 sfe_copy_data_fp (SNDFILE *outfile, SNDFILE *infile, int channels, int normalize)
 {	static double	data [BUFFER_LEN], max ;
 	int		frames, readcount, k ;
@@ -54,6 +55,8 @@ sfe_copy_data_fp (SNDFILE *outfile, SNDFILE *infile, int channels, int normalize
 	readcount = frames ;
 
 	sf_command (infile, SFC_CALC_SIGNAL_MAX, &max, sizeof (max)) ;
+	if (!isnormal (max)) /* neither zero, subnormal, infinite, nor NaN */
+		return 1 ;
 
 	if (!normalize && max < 1.0)
 	{	while (readcount > 0)
@@ -67,12 +70,16 @@ sfe_copy_data_fp (SNDFILE *outfile, SNDFILE *infile, int channels, int normalize
 		while (readcount > 0)
 		{	readcount = sf_readf_double (infile, data, frames) ;
 			for (k = 0 ; k < readcount * channels ; k++)
-				data [k] /= max ;
+			{	data [k] /= max ;
+
+				if (!isfinite (data [k])) /* infinite or NaN */
+					return 1;
+				}
 			sf_writef_double (outfile, data, readcount) ;
 			} ;
 		} ;
 
-	return ;
+	return 0 ;
 } /* sfe_copy_data_fp */
 
 void
@@ -252,7 +259,12 @@ sfe_apply_metadata_changes (const char * filenames [2], const METADATA_INFO * in
 
 		/* If the input file is not the same as the output file, copy the data. */
 		if ((infileminor == SF_FORMAT_DOUBLE) || (infileminor == SF_FORMAT_FLOAT))
-			sfe_copy_data_fp (outfile, infile, sfinfo.channels, SF_FALSE) ;
+		{	if (sfe_copy_data_fp (outfile, infile, sfinfo.channels, SF_FALSE) != 0)
+			{	printf ("Error : Not able to decode input file '%s'\n", filenames [0]) ;
+				error_code = 1 ;
+				goto cleanup_exit ;
+				} ;
+			}
 		else
 			sfe_copy_data_int (outfile, infile, sfinfo.channels) ;
 		} ;
diff --git a/programs/common.h b/programs/common.h
index eda2d7d7..986277ee 100644
--- a/programs/common.h
+++ b/programs/common.h
@@ -62,7 +62,7 @@ typedef SF_BROADCAST_INFO_VAR (2048) SF_BROADCAST_INFO_2K ;
 
 void sfe_apply_metadata_changes (const char * filenames [2], const METADATA_INFO * info) ;
 
-void sfe_copy_data_fp (SNDFILE *outfile, SNDFILE *infile, int channels, int normalize) ;
+int sfe_copy_data_fp (SNDFILE *outfile, SNDFILE *infile, int channels, int normalize) ;
 
 void sfe_copy_data_int (SNDFILE *outfile, SNDFILE *infile, int channels) ;
 
diff --git a/programs/sndfile-convert.c b/programs/sndfile-convert.c
index dff7f793..e6de5935 100644
--- a/programs/sndfile-convert.c
+++ b/programs/sndfile-convert.c
@@ -335,7 +335,11 @@ main (int argc, char * argv [])
 			|| (outfileminor == SF_FORMAT_DOUBLE) || (outfileminor == SF_FORMAT_FLOAT)
 			|| (infileminor == SF_FORMAT_DOUBLE) || (infileminor == SF_FORMAT_FLOAT)
 			|| (infileminor == SF_FORMAT_VORBIS) || (outfileminor == SF_FORMAT_VORBIS))
-		sfe_copy_data_fp (outfile, infile, sfinfo.channels, normalize) ;
+	{	if (sfe_copy_data_fp (outfile, infile, sfinfo.channels, normalize) != 0)
+		{	printf ("Error : Not able to decode input file %s.\n", infilename) ;
+			return 1 ;
+			} ;
+		}
 	else
 		sfe_copy_data_int (outfile, infile, sfinfo.channels) ;