glib: Use g_memdup2() instead of g_memdup() in obvious places

Convert all the call sites which use `g_memdup()`’s length argument
trivially (for example, by passing a `sizeof()` or an existing `gsize`
variable), so that they use `g_memdup2()` instead.

In almost all of these cases the use of `g_memdup()` would not have
caused problems, but it will soon be deprecated, so best port away from
it

In particular, this fixes an overflow within `g_bytes_new()`, identified
as GHSL-2021-045 (aka CVE-2021-27219) by GHSL team member Kevin Backhouse.

Adapted for GLib 2.58 by Simon McVittie.

Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Fixes: CVE-2021-27219
Fixes: GHSL-2021-045
Helps: #2319
(cherry picked from commit 0736b7c1e7cf4232c5d7eb2b0fbfe9be81bd3baa)
[Backport to 2.58: Omit changes to ghash.c, will be a separate commit]
[Backport to 2.58: Omit changes to giochannel.c, not needed in this branch]
[Backport to 2.58: Omit changes to uri test, not needed in this branch]
Signed-off-by: Simon McVittie <smcv@collabora.com>

glib/gbytes.c

@@ -33,6 +33,8 @@
 
 #include <string.h>
 
+#include "gstrfuncsprivate.h"
+
 /**
  * GBytes:
  *
@@ -94,7 +96,7 @@ g_bytes_new (gconstpointer data,
 {
   g_return_val_if_fail (data != NULL || size == 0, NULL);
 
-  return g_bytes_new_take (g_memdup (data, size), size);
+  return g_bytes_new_take (g_memdup2 (data, size), size);
 }
 
 /**
@@ -490,7 +492,7 @@ g_bytes_unref_to_data (GBytes *bytes,
        * Copy: Non g_malloc (or compatible) allocator, or static memory,
        * so we have to copy, and then unref.
        */
-      result = g_memdup (bytes->data, bytes->size);
+      result = g_memdup2 (bytes->data, bytes->size);
       *size = bytes->size;
       g_bytes_unref (bytes);
     }

glib/gdir.c

@@ -37,6 +37,7 @@
 #include "gconvert.h"
 #include "gfileutils.h"
 #include "gstrfuncs.h"
+#include "gstrfuncsprivate.h"
 #include "gtestutils.h"
 #include "glibintl.h"
 
@@ -113,7 +114,7 @@ g_dir_open_with_errno (const gchar *path,
     return NULL;
 #endif
 
-  return g_memdup (&dir, sizeof dir);
+  return g_memdup2 (&dir, sizeof dir);
 }
 
 /**

glib/gslice.c

@@ -45,6 +45,7 @@
 #include "gmain.h"
 #include "gmem.h"               /* gslice.h */
 #include "gstrfuncs.h"
+#include "gstrfuncsprivate.h"
 #include "gutils.h"
 #include "gtrashstack.h"
 #include "gtestutils.h"
@@ -352,7 +353,7 @@ g_slice_get_config_state (GSliceConfig ckey,
       array[i++] = allocator->contention_counters[address];
       array[i++] = allocator_get_magazine_threshold (allocator, address);
       *n_values = i;
-      return g_memdup (array, sizeof (array[0]) * *n_values);
+      return g_memdup2 (array, sizeof (array[0]) * *n_values);
     default:
       return NULL;
     }

glib/gtestutils.c

@@ -49,6 +49,7 @@
 #include "gpattern.h"
 #include "grand.h"
 #include "gstrfuncs.h"
+#include "gstrfuncsprivate.h"
 #include "gtimer.h"
 #include "gslice.h"
 #include "gspawn.h"
@@ -3397,7 +3398,7 @@ g_test_log_extract (GTestLogBuffer *tbuffer)
       if (p <= tbuffer->data->str + mlength)
         {
           g_string_erase (tbuffer->data, 0, mlength);
-          tbuffer->msgs = g_slist_prepend (tbuffer->msgs, g_memdup (&msg, sizeof (msg)));
+          tbuffer->msgs = g_slist_prepend (tbuffer->msgs, g_memdup2 (&msg, sizeof (msg)));
           return TRUE;
         }
 

glib/gvariant.c

@@ -33,6 +33,7 @@
 
 #include <string.h>
 
+#include "gstrfuncsprivate.h"
 
 /**
  * SECTION:gvariant
@@ -720,7 +721,7 @@ g_variant_new_variant (GVariant *value)
   g_variant_ref_sink (value);
 
   return g_variant_new_from_children (G_VARIANT_TYPE_VARIANT,
-                                      g_memdup (&value, sizeof value),
+                                      g_memdup2 (&value, sizeof value),
                                       1, g_variant_is_trusted (value));
 }
 
@@ -1224,7 +1225,7 @@ g_variant_new_fixed_array (const GVariantType  *element_type,
       return NULL;
     }
 
-  data = g_memdup (elements, n_elements * element_size);
+  data = g_memdup2 (elements, n_elements * element_size);
   value = g_variant_new_from_data (array_type, data,
                                    n_elements * element_size,
                                    FALSE, g_free, data);
@@ -1901,7 +1902,7 @@ g_variant_dup_bytestring (GVariant *value,
   if (length)
     *length = size;
 
-  return g_memdup (original, size + 1);
+  return g_memdup2 (original, size + 1);
 }
 
 /**

glib/gvarianttype.c

@@ -27,6 +27,7 @@
 
 #include <string.h>
 
+#include "gstrfuncsprivate.h"
 
 /**
  * SECTION:gvarianttype
@@ -1109,7 +1110,7 @@ g_variant_type_new_tuple (const GVariantType * const *items,
   g_assert (offset < sizeof buffer);
   buffer[offset++] = ')';
 
-  return (GVariantType *) g_memdup (buffer, offset);
+  return (GVariantType *) g_memdup2 (buffer, offset);
 }
 
 /**