double64_init: Check psf->sf.channels against upper bound

This prevents division by zero later in the code. While the trivial case to catch this (i.e. sf.channels < 1) has already been covered, a crafted file may report a number of channels that is so high (i.e. > INT_MAX/sizeof(double)) that it "somehow" gets miscalculated to zero (if this makes sense) in the determination of the blockwidth. Since we only support a limited number of channels anyway, make sure to check here as well. CVE-2017-14634 Closes: #318 Signed-off-by: Erik de Castro Lopo <erikd@mega-nerd.com>
libsndfile · Sep 30, 2017 · 85c877d · 85c877d
1 parent ef888c6
commit 85c877d
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/src/double64.c b/src/double64.c
@@ -91,7 +91,7 @@ int
 double64_init	(SF_PRIVATE *psf)
 {	static int double64_caps ;
 
-	if (psf->sf.channels < 1)
+	if (psf->sf.channels < 1 || psf->sf.channels > SF_MAX_CHANNELS)
 	{	psf_log_printf (psf, "double64_init : internal error : channels = %d\n", psf->sf.channels) ;
 		return SFE_INTERNAL ;
 		} ;