From 00aeede6bdba3cb74943932b24accc7ba61d2cb0 Mon Sep 17 00:00:00 2001
From: Even Rouault <even.rouault@spatialys.com>
Date: Sat, 10 Aug 2019 18:25:03 +0200
Subject: [PATCH] (CVE-2019-14973) Fix integer overflow in _TIFFCheckMalloc()
and other implementation-defined behaviour (CVE-2019-14973)
_TIFFCheckMalloc()/_TIFFCheckRealloc() used a unsafe way to detect overflow
in the multiplication of nmemb and elem_size (which are of type tmsize_t, thus
signed), which was especially easily triggered on 32-bit builds (with recent
enough compilers that assume that signed multiplication cannot overflow, since
this is undefined behaviour by the C standard). The original issue which lead to
this fix was trigged from tif_fax3.c
There were also unsafe (implementation defied), and broken in practice on 64bit
builds, ways of checking that a uint64 fits of a (signed) tmsize_t by doing
(uint64)(tmsize_t)uint64_var != uint64_var comparisons. Those have no known
at that time exploits, but are better to fix in a more bullet-proof way.
Or similarly use of (int64)uint64_var <= 0.
(cherry picked from commit 1b5e3b6a23827c33acf19ad50ce5ce78f12b3773)
---
libtiff/tif_aux.c | 49 +++++++++++++++++++++++++++++++++++++-----
libtiff/tif_getimage.c | 6 ++----
libtiff/tif_luv.c | 8 +------
libtiff/tif_pixarlog.c | 7 +-----
libtiff/tif_read.c | 38 +++++++++-----------------------
libtiff/tif_strip.c | 35 ++++--------------------------
libtiff/tif_tile.c | 27 +++--------------------
libtiff/tiffiop.h | 7 +++++-
8 files changed, 71 insertions(+), 106 deletions(-)
diff --git a/libtiff/tif_aux.c b/libtiff/tif_aux.c
index 10b8d00c..38a98b67 100644
--- a/libtiff/tif_aux.c
+++ b/libtiff/tif_aux.c
@@ -59,18 +59,57 @@ _TIFFMultiply64(TIFF* tif, uint64 first, uint64 second, const char* where)
return bytes;
}
+tmsize_t
+_TIFFMultiplySSize(TIFF* tif, tmsize_t first, tmsize_t second, const char* where)
+{
+ if( first <= 0 || second <= 0 )
+ {
+ if( tif != NULL && where != NULL )
+ {
+ TIFFErrorExt(tif->tif_clientdata, where,
+ "Invalid argument to _TIFFMultiplySSize() in %s", where);
+ }
+ return 0;
+ }
+
+ if( first > TIFF_TMSIZE_T_MAX / second )
+ {
+ if( tif != NULL && where != NULL )
+ {
+ TIFFErrorExt(tif->tif_clientdata, where,
+ "Integer overflow in %s", where);
+ }
+ return 0;
+ }
+ return first * second;
+}
+
+tmsize_t _TIFFCastUInt64ToSSize(TIFF* tif, uint64 val, const char* module)
+{
+ if( val > (uint64)TIFF_TMSIZE_T_MAX )
+ {
+ if( tif != NULL && module != NULL )
+ {
+ TIFFErrorExt(tif->tif_clientdata,module,"Integer overflow");
+ }
+ return 0;
+ }
+ return (tmsize_t)val;
+}
+
void*
_TIFFCheckRealloc(TIFF* tif, void* buffer,
tmsize_t nmemb, tmsize_t elem_size, const char* what)
{
void* cp = NULL;
- tmsize_t bytes = nmemb * elem_size;
-
+ tmsize_t count = _TIFFMultiplySSize(tif, nmemb, elem_size, NULL);
/*
- * XXX: Check for integer overflow.
+ * Check for integer overflow.
*/
- if (nmemb && elem_size && bytes / elem_size == nmemb)
- cp = _TIFFrealloc(buffer, bytes);
+ if (count != 0)
+ {
+ cp = _TIFFrealloc(buffer, count);
+ }
if (cp == NULL) {
TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
diff --git a/libtiff/tif_getimage.c b/libtiff/tif_getimage.c
index fc554cca..ec09feaf 100644
--- a/libtiff/tif_getimage.c
+++ b/libtiff/tif_getimage.c
@@ -757,9 +757,8 @@ gtTileSeparate(TIFFRGBAImage* img, uint32* raster, uint32 w, uint32 h)
uint32 leftmost_tw;
tilesize = TIFFTileSize(tif);
- bufsize = TIFFSafeMultiply(tmsize_t,alpha?4:3,tilesize);
+ bufsize = _TIFFMultiplySSize(tif, alpha?4:3,tilesize, "gtTileSeparate");
if (bufsize == 0) {
- TIFFErrorExt(tif->tif_clientdata, TIFFFileName(tif), "Integer overflow in %s", "gtTileSeparate");
return (0);
}
@@ -1021,9 +1020,8 @@ gtStripSeparate(TIFFRGBAImage* img, uint32* raster, uint32 w, uint32 h)
uint16 colorchannels;
stripsize = TIFFStripSize(tif);
- bufsize = TIFFSafeMultiply(tmsize_t,alpha?4:3,stripsize);
+ bufsize = _TIFFMultiplySSize(tif,alpha?4:3,stripsize, "gtStripSeparate");
if (bufsize == 0) {
- TIFFErrorExt(tif->tif_clientdata, TIFFFileName(tif), "Integer overflow in %s", "gtStripSeparate");
return (0);
}
diff --git a/libtiff/tif_luv.c b/libtiff/tif_luv.c
index 4b25244b..c4cb73a3 100644
--- a/libtiff/tif_luv.c
+++ b/libtiff/tif_luv.c
@@ -1264,16 +1264,10 @@ LogL16GuessDataFmt(TIFFDirectory *td)
return (SGILOGDATAFMT_UNKNOWN);
}
-
-#define TIFF_SIZE_T_MAX ((size_t) ~ ((size_t)0))
-#define TIFF_TMSIZE_T_MAX (tmsize_t)(TIFF_SIZE_T_MAX >> 1)
-
static tmsize_t
multiply_ms(tmsize_t m1, tmsize_t m2)
{
- if( m1 == 0 || m2 > TIFF_TMSIZE_T_MAX / m1 )
- return 0;
- return m1 * m2;
+ return _TIFFMultiplySSize(NULL, m1, m2, NULL);
}
static int
diff --git a/libtiff/tif_pixarlog.c b/libtiff/tif_pixarlog.c
index 979858da..8e9eaa1d 100644
--- a/libtiff/tif_pixarlog.c
+++ b/libtiff/tif_pixarlog.c
@@ -636,15 +636,10 @@ PixarLogGuessDataFmt(TIFFDirectory *td)
return guess;
}
-#define TIFF_SIZE_T_MAX ((size_t) ~ ((size_t)0))
-#define TIFF_TMSIZE_T_MAX (tmsize_t)(TIFF_SIZE_T_MAX >> 1)
-
static tmsize_t
multiply_ms(tmsize_t m1, tmsize_t m2)
{
- if( m1 == 0 || m2 > TIFF_TMSIZE_T_MAX / m1 )
- return 0;
- return m1 * m2;
+ return _TIFFMultiplySSize(NULL, m1, m2, NULL);
}
static tmsize_t
diff --git a/libtiff/tif_read.c b/libtiff/tif_read.c
index 04100f4d..9a0e6e95 100644
--- a/libtiff/tif_read.c
+++ b/libtiff/tif_read.c
@@ -31,9 +31,6 @@
#include "tiffiop.h"
#include <stdio.h>
-#define TIFF_SIZE_T_MAX ((size_t) ~ ((size_t)0))
-#define TIFF_TMSIZE_T_MAX (tmsize_t)(TIFF_SIZE_T_MAX >> 1)
-
int TIFFFillStrip(TIFF* tif, uint32 strip);
int TIFFFillTile(TIFF* tif, uint32 tile);
static int TIFFStartStrip(TIFF* tif, uint32 strip);
@@ -51,6 +48,8 @@ TIFFReadRawTile1(TIFF* tif, uint32 tile, void* buf, tmsize_t size, const char* m
#define THRESHOLD_MULTIPLIER 10
#define MAX_THRESHOLD (THRESHOLD_MULTIPLIER * THRESHOLD_MULTIPLIER * THRESHOLD_MULTIPLIER * INITIAL_THRESHOLD)
+#define TIFF_INT64_MAX ((((int64)0x7FFFFFFF) << 32) | 0xFFFFFFFF)
+
/* Read 'size' bytes in tif_rawdata buffer starting at offset 'rawdata_offset'
* Returns 1 in case of success, 0 otherwise. */
static int TIFFReadAndRealloc( TIFF* tif, tmsize_t size,
@@ -735,23 +734,8 @@ TIFFReadRawStrip(TIFF* tif, uint32 strip, void* buf, tmsize_t size)
return ((tmsize_t)(-1));
}
bytecount = td->td_stripbytecount[strip];
- if ((int64)bytecount <= 0) {
-#if defined(__WIN32__) && (defined(_MSC_VER) || defined(__MINGW32__))
- TIFFErrorExt(tif->tif_clientdata, module,
- "%I64u: Invalid strip byte count, strip %lu",
- (unsigned __int64) bytecount,
- (unsigned long) strip);
-#else
- TIFFErrorExt(tif->tif_clientdata, module,
- "%llu: Invalid strip byte count, strip %lu",
- (unsigned long long) bytecount,
- (unsigned long) strip);
-#endif
- return ((tmsize_t)(-1));
- }
- bytecountm = (tmsize_t)bytecount;
- if ((uint64)bytecountm!=bytecount) {
- TIFFErrorExt(tif->tif_clientdata, module, "Integer overflow");
+ bytecountm = _TIFFCastUInt64ToSSize(tif, bytecount, module);
+ if (bytecountm == 0) {
return ((tmsize_t)(-1));
}
if (size != (tmsize_t)(-1) && size < bytecountm)
@@ -775,7 +759,7 @@ TIFFFillStrip(TIFF* tif, uint32 strip)
if ((tif->tif_flags&TIFF_NOREADRAW)==0)
{
uint64 bytecount = td->td_stripbytecount[strip];
- if ((int64)bytecount <= 0) {
+ if( bytecount == 0 || bytecount > (uint64)TIFF_INT64_MAX ) {
#if defined(__WIN32__) && (defined(_MSC_VER) || defined(__MINGW32__))
TIFFErrorExt(tif->tif_clientdata, module,
"Invalid strip byte count %I64u, strip %lu",
@@ -802,7 +786,7 @@ TIFFFillStrip(TIFF* tif, uint32 strip)
(bytecount - 4096) / 10 > (uint64)stripsize )
{
uint64 newbytecount = (uint64)stripsize * 10 + 4096;
- if( (int64)newbytecount >= 0 )
+ if( newbytecount == 0 || newbytecount > (uint64)TIFF_INT64_MAX )
{
#if defined(__WIN32__) && (defined(_MSC_VER) || defined(__MINGW32__))
TIFFWarningExt(tif->tif_clientdata, module,
@@ -1197,10 +1181,8 @@ TIFFReadRawTile(TIFF* tif, uint32 tile, void* buf, tmsize_t size)
bytecount64 = td->td_stripbytecount[tile];
if (size != (tmsize_t)(-1) && (uint64)size < bytecount64)
bytecount64 = (uint64)size;
- bytecountm = (tmsize_t)bytecount64;
- if ((uint64)bytecountm!=bytecount64)
- {
- TIFFErrorExt(tif->tif_clientdata,module,"Integer overflow");
+ bytecountm = _TIFFCastUInt64ToSSize(tif, bytecount64, module);
+ if( bytecountm == 0 ) {
return ((tmsize_t)(-1));
}
return (TIFFReadRawTile1(tif, tile, buf, bytecountm, module));
@@ -1222,7 +1204,7 @@ TIFFFillTile(TIFF* tif, uint32 tile)
if ((tif->tif_flags&TIFF_NOREADRAW)==0)
{
uint64 bytecount = td->td_stripbytecount[tile];
- if ((int64)bytecount <= 0) {
+ if( bytecount == 0 || bytecount > (uint64)TIFF_INT64_MAX ) {
#if defined(__WIN32__) && (defined(_MSC_VER) || defined(__MINGW32__))
TIFFErrorExt(tif->tif_clientdata, module,
"%I64u: Invalid tile byte count, tile %lu",
@@ -1249,7 +1231,7 @@ TIFFFillTile(TIFF* tif, uint32 tile)
(bytecount - 4096) / 10 > (uint64)stripsize )
{
uint64 newbytecount = (uint64)stripsize * 10 + 4096;
- if( (int64)newbytecount >= 0 )
+ if( newbytecount == 0 || newbytecount > (uint64)TIFF_INT64_MAX )
{
#if defined(__WIN32__) && (defined(_MSC_VER) || defined(__MINGW32__))
TIFFWarningExt(tif->tif_clientdata, module,
diff --git a/libtiff/tif_strip.c b/libtiff/tif_strip.c
index 6e9f2ef6..321ad6b9 100644
--- a/libtiff/tif_strip.c
+++ b/libtiff/tif_strip.c
@@ -131,15 +131,8 @@ TIFFVStripSize(TIFF* tif, uint32 nrows)
{
static const char module[] = "TIFFVStripSize";
uint64 m;
- tmsize_t n;
m=TIFFVStripSize64(tif,nrows);
- n=(tmsize_t)m;
- if ((uint64)n!=m)
- {
- TIFFErrorExt(tif->tif_clientdata,module,"Integer overflow");
- n=0;
- }
- return(n);
+ return _TIFFCastUInt64ToSSize(tif, m, module);
}
/*
@@ -213,15 +206,8 @@ TIFFStripSize(TIFF* tif)
{
static const char module[] = "TIFFStripSize";
uint64 m;
- tmsize_t n;
m=TIFFStripSize64(tif);
- n=(tmsize_t)m;
- if ((uint64)n!=m)
- {
- TIFFErrorExt(tif->tif_clientdata,module,"Integer overflow");
- n=0;
- }
- return(n);
+ return _TIFFCastUInt64ToSSize(tif, m, module);
}
/*
@@ -332,14 +318,8 @@ TIFFScanlineSize(TIFF* tif)
{
static const char module[] = "TIFFScanlineSize";
uint64 m;
- tmsize_t n;
m=TIFFScanlineSize64(tif);
- n=(tmsize_t)m;
- if ((uint64)n!=m) {
- TIFFErrorExt(tif->tif_clientdata,module,"Integer arithmetic overflow");
- n=0;
- }
- return(n);
+ return _TIFFCastUInt64ToSSize(tif, m, module);
}
/*
@@ -368,15 +348,8 @@ TIFFRasterScanlineSize(TIFF* tif)
{
static const char module[] = "TIFFRasterScanlineSize";
uint64 m;
- tmsize_t n;
m=TIFFRasterScanlineSize64(tif);
- n=(tmsize_t)m;
- if ((uint64)n!=m)
- {
- TIFFErrorExt(tif->tif_clientdata,module,"Integer arithmetic overflow");
- n=0;
- }
- return(n);
+ return _TIFFCastUInt64ToSSize(tif, m, module);
}
/* vim: set ts=8 sts=8 sw=8 noet: */
diff --git a/libtiff/tif_tile.c b/libtiff/tif_tile.c
index 388e168a..7d057509 100644
--- a/libtiff/tif_tile.c
+++ b/libtiff/tif_tile.c
@@ -183,15 +183,8 @@ TIFFTileRowSize(TIFF* tif)
{
static const char module[] = "TIFFTileRowSize";
uint64 m;
- tmsize_t n;
m=TIFFTileRowSize64(tif);
- n=(tmsize_t)m;
- if ((uint64)n!=m)
- {
- TIFFErrorExt(tif->tif_clientdata,module,"Integer overflow");
- n=0;
- }
- return(n);
+ return _TIFFCastUInt64ToSSize(tif, m, module);
}
/*
@@ -250,15 +243,8 @@ TIFFVTileSize(TIFF* tif, uint32 nrows)
{
static const char module[] = "TIFFVTileSize";
uint64 m;
- tmsize_t n;
m=TIFFVTileSize64(tif,nrows);
- n=(tmsize_t)m;
- if ((uint64)n!=m)
- {
- TIFFErrorExt(tif->tif_clientdata,module,"Integer overflow");
- n=0;
- }
- return(n);
+ return _TIFFCastUInt64ToSSize(tif, m, module);
}
/*
@@ -274,15 +260,8 @@ TIFFTileSize(TIFF* tif)
{
static const char module[] = "TIFFTileSize";
uint64 m;
- tmsize_t n;
m=TIFFTileSize64(tif);
- n=(tmsize_t)m;
- if ((uint64)n!=m)
- {
- TIFFErrorExt(tif->tif_clientdata,module,"Integer overflow");
- n=0;
- }
- return(n);
+ return _TIFFCastUInt64ToSSize(tif, m, module);
}
/*
diff --git a/libtiff/tiffiop.h b/libtiff/tiffiop.h
index 08e5dc44..d4b86314 100644
--- a/libtiff/tiffiop.h
+++ b/libtiff/tiffiop.h
@@ -79,6 +79,9 @@ extern int snprintf(char* str, size_t size, const char* format, ...);
#define FALSE 0
#endif
+#define TIFF_SIZE_T_MAX ((size_t) ~ ((size_t)0))
+#define TIFF_TMSIZE_T_MAX (tmsize_t)(TIFF_SIZE_T_MAX >> 1)
+
typedef struct client_info {
struct client_info *next;
void *data;
@@ -260,7 +263,7 @@ struct tiff {
#define TIFFhowmany8_64(x) (((x)&0x07)?((uint64)(x)>>3)+1:(uint64)(x)>>3)
#define TIFFroundup_64(x, y) (TIFFhowmany_64(x,y)*(y))
-/* Safe multiply which returns zero if there is an integer overflow */
+/* Safe multiply which returns zero if there is an *unsigned* integer overflow. This macro is not safe for *signed* integer types */
#define TIFFSafeMultiply(t,v,m) ((((t)(m) != (t)0) && (((t)(((v)*(m))/(m))) == (t)(v))) ? (t)((v)*(m)) : (t)0)
#define TIFFmax(A,B) ((A)>(B)?(A):(B))
@@ -366,6 +369,8 @@ extern TIFFErrorHandlerExt _TIFFerrorHandlerExt;
extern uint32 _TIFFMultiply32(TIFF*, uint32, uint32, const char*);
extern uint64 _TIFFMultiply64(TIFF*, uint64, uint64, const char*);
+extern tmsize_t _TIFFMultiplySSize(TIFF*, tmsize_t, tmsize_t, const char*);
+extern tmsize_t _TIFFCastUInt64ToSSize(TIFF*, uint64, const char*);
extern void* _TIFFCheckMalloc(TIFF*, tmsize_t, tmsize_t, const char*);
extern void* _TIFFCheckRealloc(TIFF*, void*, tmsize_t, tmsize_t, const char*);