package/mupdf: fix CVE-2021-37220

MuPDF through 1.18.1 has an out-of-bounds write because the cached color
converter does not properly consider the maximum key size of a hash
table. This can, for example, be seen with crafted "mutool draw" input.

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

diff --git a/package/mupdf/0003-Bug-703791-Stay-within-hash-table-max-key-size-in-cached-color-converter.patch b/package/mupdf/0003-Bug-703791-Stay-within-hash-table-max-key-size-in-cached-color-converter.patch
new file mode 100644 (file)
index 0000000..5335f14
--- /dev/null
+++ b/package/mupdf/0003-Bug-703791-Stay-within-hash-table-max-key-size-in-cached-color-converter.patch
@@ -0,0 +1,119 @@
+From f5712c9949d026e4b891b25837edd2edc166151f Mon Sep 17 00:00:00 2001
+From: Tor Andersson <tor.andersson@artifex.com>
+Date: Tue, 20 Apr 2021 14:46:48 +0200
+Subject: [PATCH] Bug 703791: Stay within hash table max key size in cached
+ color converter.
+
+[Retrieved from:
+http://git.ghostscript.com/?p=mupdf.git;h=f5712c9949d026e4b891b25837edd2edc166151f]
+Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+---
+ include/mupdf/fitz/hash.h |  2 ++
+ source/fitz/colorspace.c  | 40 ++++++++++++++++++++++++---------------
+ source/fitz/hash.c        |  7 +++----
+ 3 files changed, 30 insertions(+), 19 deletions(-)
+
+diff --git a/include/mupdf/fitz/hash.h b/include/mupdf/fitz/hash.h
+index e92eb0458..feb37a5e4 100644
+--- a/include/mupdf/fitz/hash.h
++++ b/include/mupdf/fitz/hash.h
+@@ -5,6 +5,8 @@
+ #include "mupdf/fitz/context.h"
+ #include "mupdf/fitz/output.h"
+ 
++#define FZ_HASH_TABLE_KEY_LENGTH 48
++
+ /**
+       Generic hash-table with fixed-length keys.
+ 
+diff --git a/source/fitz/colorspace.c b/source/fitz/colorspace.c
+index af454caf1..f4db9d3d2 100644
+--- a/source/fitz/colorspace.c
++++ b/source/fitz/colorspace.c
+@@ -1025,23 +1025,30 @@ typedef struct fz_cached_color_converter
+ static void fz_cached_color_convert(fz_context *ctx, fz_color_converter *cc_, const float *ss, float *ds)
+ {
+       fz_cached_color_converter *cc = cc_->opaque;
+-      float *val = fz_hash_find(ctx, cc->hash, ss);
+-      int n = cc->base.ds->n * sizeof(float);
+-
+-      if (val)
++      if (cc->hash)
+       {
+-              memcpy(ds, val, n);
+-              return;
+-      }
++              float *val = fz_hash_find(ctx, cc->hash, ss);
++              int n = cc->base.ds->n * sizeof(float);
+ 
+-      cc->base.convert(ctx, &cc->base, ss, ds);
++              if (val)
++              {
++                      memcpy(ds, val, n);
++                      return;
++              }
+ 
+-      val = Memento_label(fz_malloc_array(ctx, cc->base.ds->n, float), "cached_color_convert");
+-      memcpy(val, ds, n);
+-      fz_try(ctx)
+-              fz_hash_insert(ctx, cc->hash, ss, val);
+-      fz_catch(ctx)
+-              fz_free(ctx, val);
++              cc->base.convert(ctx, &cc->base, ss, ds);
++
++              val = Memento_label(fz_malloc_array(ctx, cc->base.ds->n, float), "cached_color_convert");
++              memcpy(val, ds, n);
++              fz_try(ctx)
++                      fz_hash_insert(ctx, cc->hash, ss, val);
++              fz_catch(ctx)
++                      fz_free(ctx, val);
++      }
++      else
++      {
++              cc->base.convert(ctx, &cc->base, ss, ds);
++      }
+ }
+ 
+ void fz_init_cached_color_converter(fz_context *ctx, fz_color_converter *cc, fz_colorspace *ss, fz_colorspace *ds, fz_colorspace *is, fz_color_params params)
+@@ -1060,7 +1067,10 @@ void fz_init_cached_color_converter(fz_context *ctx, fz_color_converter *cc, fz_
+       fz_try(ctx)
+       {
+               fz_find_color_converter(ctx, &cached->base, ss, ds, is, params);
+-              cached->hash = fz_new_hash_table(ctx, 256, n * sizeof(float), -1, fz_free);
++              if (n * sizeof(float) <= FZ_HASH_TABLE_KEY_LENGTH)
++                      cached->hash = fz_new_hash_table(ctx, 256, n * sizeof(float), -1, fz_free);
++              else
++                      fz_warn(ctx, "colorspace has too many components to be cached");
+       }
+       fz_catch(ctx)
+       {
+diff --git a/source/fitz/hash.c b/source/fitz/hash.c
+index 882b886c9..287d43f03 100644
+--- a/source/fitz/hash.c
++++ b/source/fitz/hash.c
+@@ -11,11 +11,9 @@
+       and removed frequently.
+ */
+ 
+-enum { MAX_KEY_LEN = 48 };
+-
+ typedef struct
+ {
+-      unsigned char key[MAX_KEY_LEN];
++      unsigned char key[FZ_HASH_TABLE_KEY_LENGTH];
+       void *val;
+ } fz_hash_entry;
+ 
+@@ -50,7 +48,8 @@ fz_new_hash_table(fz_context *ctx, int initialsize, int keylen, int lock, fz_has
+ {
+       fz_hash_table *table;
+ 
+-      assert(keylen <= MAX_KEY_LEN);
++      if (keylen > FZ_HASH_TABLE_KEY_LENGTH)
++              fz_throw(ctx, FZ_ERROR_GENERIC, "hash table key length too large");
+ 
+       table = fz_malloc_struct(ctx, fz_hash_table);
+       table->keylen = keylen;
+-- 
+2.17.1
+

diff --git a/package/mupdf/mupdf.mk b/package/mupdf/mupdf.mk
index d3d9d3b10160f893637f84101634e425188564b7..c9d5b4a162cfd83d0e2409fb90adb103074696b2 100644 (file)
--- a/package/mupdf/mupdf.mk
+++ b/package/mupdf/mupdf.mk
@@ -25,6 +25,9 @@ MUPDF_DEPENDENCIES = \
 # 0002-Bug-703366-Fix-double-free-of-object-during-linearization.patch
 MUPDF_IGNORE_CVES += CVE-2021-3407
 
+# 0003-Bug-703791-Stay-within-hash-table-max-key-size-in-cached-color-converter.patch
+MUPDF_IGNORE_CVES += CVE-2021-37220
+
 # The pkg-config name for gumbo-parser is `gumbo`.
 MUPDF_PKG_CONFIG_PACKAGES = \
        freetype2 \