diff --git a/attr.c b/attr.c
index 679e42258c..7c380c1731 100644
--- a/attr.c
+++ b/attr.c
@@ -765,8 +765,8 @@ static struct attr_stack *read_attr_from_file(const char *path, unsigned flags)
 	return res;
 }
 
-static struct attr_stack *read_attr_from_buf(char *buf, const char *path,
-					     unsigned flags)
+static struct attr_stack *read_attr_from_buf(char *buf, size_t length,
+					     const char *path, unsigned flags)
 {
 	struct attr_stack *res;
 	char *sp;
@@ -774,6 +774,11 @@ static struct attr_stack *read_attr_from_buf(char *buf, const char *path,
 
 	if (!buf)
 		return NULL;
+	if (length >= ATTR_MAX_FILE_SIZE) {
+		warning(_("ignoring overly large gitattributes blob '%s'"), path);
+		free(buf);
+		return NULL;
+	}
 
 	CALLOC_ARRAY(res, 1);
 	for (sp = buf; *sp;) {
@@ -813,7 +818,7 @@ static struct attr_stack *read_attr_from_blob(struct index_state *istate,
 		return NULL;
 	}
 
-	return read_attr_from_buf(buf, path, flags);
+	return read_attr_from_buf(buf, sz, path, flags);
 }
 
 static struct attr_stack *read_attr_from_index(struct index_state *istate,
@@ -860,13 +865,7 @@ static struct attr_stack *read_attr_from_index(struct index_state *istate,
 		stack = read_attr_from_blob(istate, &istate->cache[sparse_dir_pos]->oid, relative_path, flags);
 	} else {
 		buf = read_blob_data_from_index(istate, path, &size);
-		if (!buf)
-			return NULL;
-		if (size >= ATTR_MAX_FILE_SIZE) {
-			warning(_("ignoring overly large gitattributes blob '%s'"), path);
-			return NULL;
-		}
-		stack = read_attr_from_buf(buf, path, flags);
+		stack = read_attr_from_buf(buf, size, path, flags);
 	}
 	return stack;
 }
diff --git a/t/t0003-attributes.sh b/t/t0003-attributes.sh
index 774b52c298..b007f76fd6 100755
--- a/t/t0003-attributes.sh
+++ b/t/t0003-attributes.sh
@@ -572,6 +572,16 @@ test_expect_success EXPENSIVE 'large attributes file ignored in index' '
 	test_cmp expect err
 '
 
+test_expect_success EXPENSIVE 'large attributes blob ignored' '
+	test_when_finished "git update-index --remove .gitattributes" &&
+	blob=$(dd if=/dev/zero bs=1048576 count=101 2>/dev/null | git hash-object -w --stdin) &&
+	git update-index --add --cacheinfo 100644,$blob,.gitattributes &&
+	tree="$(git write-tree)" &&
+	git check-attr --cached --all --source="$tree" path >/dev/null 2>err &&
+	echo "warning: ignoring overly large gitattributes blob ${SQ}.gitattributes${SQ}" >expect &&
+	test_cmp expect err
+'
+
 test_expect_success 'builtin object mode attributes work (dir and regular paths)' '
 	>normal &&
 	attr_check_object_mode normal 100644 &&