diff --git a/upb/message/internal/map_sorter.h b/upb/message/internal/map_sorter.h
index 12f7e7a81add..64d6d14d44b7 100644
--- a/upb/message/internal/map_sorter.h
+++ b/upb/message/internal/map_sorter.h
@@ -12,6 +12,7 @@
 
 #include <stdlib.h>
 
+#include "upb/mem/alloc.h"
 #include "upb/message/internal/extension.h"
 #include "upb/message/internal/map.h"
 #include "upb/message/internal/map_entry.h"
@@ -46,7 +47,7 @@ UPB_INLINE void _upb_mapsorter_init(_upb_mapsorter* s) {
 }
 
 UPB_INLINE void _upb_mapsorter_destroy(_upb_mapsorter* s) {
-  if (s->entries) free(s->entries);
+  if (s->entries) upb_gfree(s->entries);
 }
 
 UPB_INLINE bool _upb_sortedmap_next(_upb_mapsorter* s, const upb_Map* map,
diff --git a/upb/message/map_sorter.c b/upb/message/map_sorter.c
index 42dc4b5ec34e..3536e35f66f6 100644
--- a/upb/message/map_sorter.c
+++ b/upb/message/map_sorter.c
@@ -7,7 +7,14 @@
 
 #include "upb/message/internal/map_sorter.h"
 
+#include <stdint.h>
+#include <string.h>
+
+#include "upb/base/descriptor_constants.h"
 #include "upb/base/internal/log2.h"
+#include "upb/base/string_view.h"
+#include "upb/mem/alloc.h"
+#include "upb/message/map.h"
 #include "upb/mini_table/extension.h"
 
 // Must be last.
@@ -91,8 +98,10 @@ static bool _upb_mapsorter_resize(_upb_mapsorter* s, _upb_sortedmap* sorted,
   sorted->end = sorted->start + size;
 
   if (sorted->end > s->cap) {
+    const int oldsize = s->cap * sizeof(*s->entries);
     s->cap = upb_Log2CeilingSize(sorted->end);
-    s->entries = realloc(s->entries, s->cap * sizeof(*s->entries));
+    const int newsize = s->cap * sizeof(*s->entries);
+    s->entries = upb_grealloc(s->entries, oldsize, newsize);
     if (!s->entries) return false;
   }
 
diff --git a/upb/reflection/def_pool.c b/upb/reflection/def_pool.c
index 83759d0a3975..0250d1b0d27a 100644
--- a/upb/reflection/def_pool.c
+++ b/upb/reflection/def_pool.c
@@ -10,6 +10,8 @@
 #include "upb/base/status.h"
 #include "upb/hash/int_table.h"
 #include "upb/hash/str_table.h"
+#include "upb/mem/alloc.h"
+#include "upb/mem/arena.h"
 #include "upb/reflection/def_type.h"
 #include "upb/reflection/file_def.h"
 #include "upb/reflection/internal/def_builder.h"
@@ -504,7 +506,7 @@ const upb_FieldDef** upb_DefPool_GetAllExtensions(const upb_DefPool* s,
     const upb_FieldDef* f = upb_value_getconstptr(val);
     if (upb_FieldDef_ContainingType(f) == m) n++;
   }
-  const upb_FieldDef** exts = malloc(n * sizeof(*exts));
+  const upb_FieldDef** exts = upb_gmalloc(n * sizeof(*exts));
   iter = UPB_INTTABLE_BEGIN;
   size_t i = 0;
   while (upb_inttable_next(&s->exts, &key, &val, &iter)) {
diff --git a/upb/reflection/internal/def_builder.c b/upb/reflection/internal/def_builder.c
index d6737982caa3..7558c9ebe9e2 100644
--- a/upb/reflection/internal/def_builder.c
+++ b/upb/reflection/internal/def_builder.c
@@ -10,6 +10,7 @@
 #include <string.h>
 
 #include "upb/base/internal/log2.h"
+#include "upb/mem/alloc.h"
 #include "upb/message/copy.h"
 #include "upb/reflection/def_pool.h"
 #include "upb/reflection/def_type.h"
@@ -116,15 +117,15 @@ const void* _upb_DefBuilder_ResolveAny(upb_DefBuilder* ctx,
   if (sym.size == 0) goto notfound;
   upb_value v;
   if (sym.data[0] == '.') {
-    /* Symbols starting with '.' are absolute, so we do a single lookup.
-     * Slice to omit the leading '.' */
+    // Symbols starting with '.' are absolute, so we do a single lookup.
+    // Slice to omit the leading '.'
     if (!_upb_DefPool_LookupSym(ctx->symtab, sym.data + 1, sym.size - 1, &v)) {
       goto notfound;
     }
   } else {
-    /* Remove components from base until we find an entry or run out. */
+    // Remove components from base until we find an entry or run out.
     size_t baselen = base ? strlen(base) : 0;
-    char* tmp = malloc(sym.size + baselen + 1);
+    char* tmp = upb_gmalloc(sym.size + baselen + 1);
     while (1) {
       char* p = tmp;
       if (baselen) {
@@ -138,11 +139,11 @@ const void* _upb_DefBuilder_ResolveAny(upb_DefBuilder* ctx,
         break;
       }
       if (!remove_component(tmp, &baselen)) {
-        free(tmp);
+        upb_gfree(tmp);
         goto notfound;
       }
     }
-    free(tmp);
+    upb_gfree(tmp);
   }
 
   *type = _upb_DefType_Type(v);
diff --git a/upb/util/BUILD b/upb/util/BUILD
index 8efb0b1f68b0..d2279918da5f 100644
--- a/upb/util/BUILD
+++ b/upb/util/BUILD
@@ -98,6 +98,7 @@ cc_library(
     visibility = ["//visibility:public"],
     deps = [
         "//upb:base",
+        "//upb:mem",
         "//upb:message",
         "//upb:port",
         "//upb:reflection",
@@ -149,6 +150,7 @@ cc_library(
     deps = [
         "//upb:base",
         "//upb:eps_copy_input_stream",
+        "//upb:mem",
         "//upb:port",
         "//upb:wire_reader",
         "//upb:wire_types",
diff --git a/upb/util/compare.c b/upb/util/compare.c
index 2a774d04e3e4..9d2907597414 100644
--- a/upb/util/compare.c
+++ b/upb/util/compare.c
@@ -10,6 +10,7 @@
 #include <stdlib.h>
 
 #include "upb/base/string_view.h"
+#include "upb/mem/alloc.h"
 #include "upb/wire/eps_copy_input_stream.h"
 #include "upb/wire/reader.h"
 #include "upb/wire/types.h"
@@ -108,9 +109,11 @@ static void upb_UnknownFields_SortRecursive(upb_UnknownField* arr, size_t start,
 static void upb_UnknownFields_Sort(upb_UnknownField_Context* ctx,
                                    upb_UnknownFields* fields) {
   if (ctx->tmp_size < fields->size) {
+    const int oldsize = ctx->tmp_size * sizeof(*ctx->tmp);
     ctx->tmp_size = UPB_MAX(8, ctx->tmp_size);
     while (ctx->tmp_size < fields->size) ctx->tmp_size *= 2;
-    ctx->tmp = realloc(ctx->tmp, ctx->tmp_size * sizeof(*ctx->tmp));
+    const int newsize = ctx->tmp_size * sizeof(*ctx->tmp);
+    ctx->tmp = upb_grealloc(ctx->tmp, oldsize, newsize);
   }
   upb_UnknownFields_SortRecursive(fields->fields, 0, fields->size, ctx->tmp);
 }
@@ -261,7 +264,7 @@ static upb_UnknownCompareResult upb_UnknownField_Compare(
   }
 
   upb_Arena_Free(ctx->arena);
-  free(ctx->tmp);
+  upb_gfree(ctx->tmp);
   return ret;
 }
 
diff --git a/upb/util/required_fields.c b/upb/util/required_fields.c
index b93adc0d9958..c3723863c030 100644
--- a/upb/util/required_fields.c
+++ b/upb/util/required_fields.c
@@ -17,6 +17,7 @@
 #include <string.h>
 
 #include "upb/base/descriptor_constants.h"
+#include "upb/mem/alloc.h"
 #include "upb/message/array.h"
 #include "upb/message/map.h"
 #include "upb/message/message.h"
@@ -168,10 +169,12 @@ static void upb_FieldPathVector_Reserve(upb_FindContext* ctx,
                                         upb_FieldPathVector* vec,
                                         size_t elems) {
   if (vec->cap - vec->size < elems) {
+    const int oldsize = vec->cap * sizeof(*vec->path);
     size_t need = vec->size + elems;
     vec->cap = UPB_MAX(4, vec->cap);
     while (vec->cap < need) vec->cap *= 2;
-    vec->path = realloc(vec->path, vec->cap * sizeof(*vec->path));
+    const int newsize = vec->cap * sizeof(*vec->path);
+    vec->path = upb_grealloc(vec->path, oldsize, newsize);
     if (!vec->path) {
       UPB_LONGJMP(ctx->err, 1);
     }
@@ -289,7 +292,7 @@ bool upb_util_HasUnsetRequired(const upb_Message* msg, const upb_MessageDef* m,
   upb_FieldPathVector_Init(&ctx.stack);
   upb_FieldPathVector_Init(&ctx.out_fields);
   upb_util_FindUnsetRequiredInternal(&ctx, msg, m);
-  free(ctx.stack.path);
+  upb_gfree(ctx.stack.path);
 
   if (ctx.has_unset_required && fields) {
     upb_FieldPathVector_Reserve(&ctx, &ctx.out_fields, 1);