cjpeg: Fix OOB read caused by malformed 8-bit BMP

... in which one or more of the color indices is out of range for the
number of palette entries.

Fix partly borrowed from jpeg-9c.  This commit also adopts Guido's
JERR_PPM_OUTOFRANGE enum value in lieu of our project-specific
JERR_PPM_TOOLARGE enum value.

Fixes #258

ChangeLog.md

@@ -47,6 +47,11 @@ a 4:2:2 or 4:2:0 JPEG image using the merged (non-fancy) upsampling algorithms
 7. The new CMake-based build system will now disable the MIPS DSPr2 SIMD
 extensions if it detects that the compiler does not support DSPr2 instructions.
 
+8. Fixed out-of-bounds read in cjpeg that occurred when attempting to compress
+a specially-crafted malformed color-index (8-bit-per-sample) BMP file in which
+some of the samples (color indices) exceeded the bounds of the BMP file's color
+table.
+
 
 1.5.90 (2.0 beta1)
 ==================

cderror.h

@@ -2,7 +2,7 @@
  * cderror.h
  *
  * Copyright (C) 1994-1997, Thomas G. Lane.
- * Modified 2009 by Guido Vollbeding.
+ * Modified 2009-2017 by Guido Vollbeding.
  * This file is part of the Independent JPEG Group's software.
  * For conditions of distribution and use, see the accompanying README.ijg
  * file.
@@ -49,6 +49,7 @@ JMESSAGE(JERR_BMP_COLORSPACE, "BMP output must be grayscale or RGB")
 JMESSAGE(JERR_BMP_COMPRESSED, "Sorry, compressed BMPs not yet supported")
 JMESSAGE(JERR_BMP_EMPTY, "Empty BMP image")
 JMESSAGE(JERR_BMP_NOT, "Not a BMP file - does not start with BM")
+JMESSAGE(JERR_BMP_OUTOFRANGE, "Numeric value out of range in BMP file")
 JMESSAGE(JTRC_BMP, "%ux%u 24-bit BMP image")
 JMESSAGE(JTRC_BMP_MAPPED, "%ux%u 8-bit colormapped BMP image")
 JMESSAGE(JTRC_BMP_OS2, "%ux%u 24-bit OS2 BMP image")
@@ -75,8 +76,8 @@ JMESSAGE(JWRN_GIF_NOMOREDATA, "Ran out of GIF bits")
 #ifdef PPM_SUPPORTED
 JMESSAGE(JERR_PPM_COLORSPACE, "PPM output must be grayscale or RGB")
 JMESSAGE(JERR_PPM_NONNUMERIC, "Nonnumeric data in PPM file")
-JMESSAGE(JERR_PPM_TOOLARGE, "Integer value too large in PPM file")
 JMESSAGE(JERR_PPM_NOT, "Not a PPM/PGM file")
+JMESSAGE(JERR_PPM_OUTOFRANGE, "Numeric value out of range in PPM file")
 JMESSAGE(JTRC_PGM, "%ux%u PGM image")
 JMESSAGE(JTRC_PGM_TEXT, "%ux%u text PGM image")
 JMESSAGE(JTRC_PPM, "%ux%u PPM image")

rdbmp.c

@@ -3,7 +3,7 @@
  *
  * This file was part of the Independent JPEG Group's software:
  * Copyright (C) 1994-1996, Thomas G. Lane.
- * Modified 2009-2010 by Guido Vollbeding.
+ * Modified 2009-2017 by Guido Vollbeding.
  * libjpeg-turbo Modifications:
  * Modified 2011 by Siarhei Siamashka.
  * Copyright (C) 2015, 2017-2018, D. R. Commander.
@@ -72,6 +72,7 @@ typedef struct _bmp_source_struct {
   JDIMENSION row_width;         /* Physical width of scanlines in file */
 
   int bits_per_pixel;           /* remembers 8- or 24-bit format */
+  int cmap_length;              /* colormap length */
 
   boolean use_inversion_array;  /* TRUE = preload the whole image, which is
                                    stored in bottom-up order, and feed it to
@@ -155,6 +156,7 @@ get_8bit_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
 {
   bmp_source_ptr source = (bmp_source_ptr)sinfo;
   register JSAMPARRAY colormap = source->colormap;
+  int cmaplen = source->cmap_length;
   JSAMPARRAY image_ptr;
   register int t;
   register JSAMPROW inptr, outptr;
@@ -178,11 +180,15 @@ get_8bit_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
   if (cinfo->in_color_space == JCS_GRAYSCALE) {
     for (col = cinfo->image_width; col > 0; col--) {
       t = GETJSAMPLE(*inptr++);
+      if (t >= cmaplen)
+        ERREXIT(cinfo, JERR_BMP_OUTOFRANGE);
       *outptr++ = colormap[0][t];
     }
   } else if (cinfo->in_color_space == JCS_CMYK) {
     for (col = cinfo->image_width; col > 0; col--) {
       t = GETJSAMPLE(*inptr++);
+      if (t >= cmaplen)
+        ERREXIT(cinfo, JERR_BMP_OUTOFRANGE);
       rgb_to_cmyk(colormap[0][t], colormap[1][t], colormap[2][t], outptr,
                   outptr + 1, outptr + 2, outptr + 3);
       outptr += 4;
@@ -197,6 +203,8 @@ get_8bit_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
     if (aindex >= 0) {
       for (col = cinfo->image_width; col > 0; col--) {
         t = GETJSAMPLE(*inptr++);
+        if (t >= cmaplen)
+          ERREXIT(cinfo, JERR_BMP_OUTOFRANGE);
         outptr[rindex] = colormap[0][t];
         outptr[gindex] = colormap[1][t];
         outptr[bindex] = colormap[2][t];
@@ -206,6 +214,8 @@ get_8bit_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
     } else {
       for (col = cinfo->image_width; col > 0; col--) {
         t = GETJSAMPLE(*inptr++);
+        if (t >= cmaplen)
+          ERREXIT(cinfo, JERR_BMP_OUTOFRANGE);
         outptr[rindex] = colormap[0][t];
         outptr[gindex] = colormap[1][t];
         outptr[bindex] = colormap[2][t];
@@ -539,6 +549,7 @@ start_input_bmp(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
     /* Allocate space to store the colormap */
     source->colormap = (*cinfo->mem->alloc_sarray)
       ((j_common_ptr)cinfo, JPOOL_IMAGE, (JDIMENSION)biClrUsed, (JDIMENSION)3);
+    source->cmap_length = (int)biClrUsed;
     /* and read it from the file */
     read_colormap(source, (int)biClrUsed, mapentrysize);
     /* account for size of colormap */

rdppm.c

@@ -75,7 +75,7 @@ typedef struct {
   JSAMPROW pixrow;              /* compressor input buffer */
   size_t buffer_width;          /* width of I/O buffer */
   JSAMPLE *rescale;             /* => maxval-remapping array, or NULL */
-  int maxval;
+  unsigned int maxval;
 } ppm_source_struct;
 
 typedef ppm_source_struct *ppm_source_ptr;
@@ -125,7 +125,7 @@ read_pbm_integer(j_compress_ptr cinfo, FILE *infile, unsigned int maxval)
   }
 
   if (val > maxval)
-    ERREXIT(cinfo, JERR_PPM_TOOLARGE);
+    ERREXIT(cinfo, JERR_PPM_OUTOFRANGE);
 
   return val;
 }
@@ -509,7 +509,7 @@ get_word_gray_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
     temp  = UCH(*bufferptr++) << 8;
     temp |= UCH(*bufferptr++);
     if (temp > maxval)
-      ERREXIT(cinfo, JERR_PPM_TOOLARGE);
+      ERREXIT(cinfo, JERR_PPM_OUTOFRANGE);
     *ptr++ = rescale[temp];
   }
   return 1;
@@ -536,17 +536,17 @@ get_word_rgb_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
     temp  = UCH(*bufferptr++) << 8;
     temp |= UCH(*bufferptr++);
     if (temp > maxval)
-      ERREXIT(cinfo, JERR_PPM_TOOLARGE);
+      ERREXIT(cinfo, JERR_PPM_OUTOFRANGE);
     *ptr++ = rescale[temp];
     temp  = UCH(*bufferptr++) << 8;
     temp |= UCH(*bufferptr++);
     if (temp > maxval)
-      ERREXIT(cinfo, JERR_PPM_TOOLARGE);
+      ERREXIT(cinfo, JERR_PPM_OUTOFRANGE);
     *ptr++ = rescale[temp];
     temp  = UCH(*bufferptr++) << 8;
     temp |= UCH(*bufferptr++);
     if (temp > maxval)
-      ERREXIT(cinfo, JERR_PPM_TOOLARGE);
+      ERREXIT(cinfo, JERR_PPM_OUTOFRANGE);
     *ptr++ = rescale[temp];
   }
   return 1;