Add fuzzer for unit file parser

2 files changed, 62 insertions, 3 deletions

diff --git a/src/fuzz/fuzz-unit-file.c b/src/fuzz/fuzz-unit-file.c
new file mode 100644
index 0000000000..87e0b10f00
--- /dev/null
+++ b/src/fuzz/fuzz-unit-file.c
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include "conf-parser.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "fuzz.h"
+#include "install.h"
+#include "load-fragment.h"
+#include "string-util.h"
+#include "unit.h"
+
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+        _cleanup_free_ char *out = NULL; /* out should be freed after g */
+        size_t out_size;
+        _cleanup_fclose_ FILE *f = NULL, *g = NULL;
+        _cleanup_free_ char *p = NULL;
+        UnitType t;
+        _cleanup_(manager_freep) Manager *m = NULL;
+        Unit *u;
+        const char *name;
+
+        if (size == 0)
+                return 0;
+
+        f = fmemopen((char*) data, size, "re");
+        assert_se(f);
+
+        if (read_line(f, LINE_MAX, &p) < 0)
+                return 0;
+
+        t = unit_type_from_string(p);
+        if (t < 0)
+                return 0;
+
+        if (!unit_vtable[t]->load)
+                return 0;
+
+        assert_se(manager_new(UNIT_FILE_SYSTEM, MANAGER_TEST_RUN_MINIMAL, &m) >= 0);
+
+        name = strjoina("a.", unit_type_to_string(t));
+        assert_se(unit_new_for_name(m, unit_vtable[t]->object_size, name, &u) >= 0);
+
+        (void) config_parse(name, name, f,
+                            UNIT_VTABLE(u)->sections,
+                            config_item_perf_lookup, load_fragment_gperf_lookup,
+                            CONFIG_PARSE_ALLOW_INCLUDE, u);
+
+        g = open_memstream(&out, &out_size);
+        assert_se(g);
+
+        unit_dump(u, g, "");
+
+        return 0;
+}
diff --git a/src/fuzz/meson.build b/src/fuzz/meson.build
index 09a8c8a11d..796c28e429 100644
--- a/src/fuzz/meson.build
+++ b/src/fuzz/meson.build
@@ -22,9 +22,14 @@ fuzzers += [
          [libgcrypt,
           libgpg_error,
           libm]],
-        [['src/fuzz/fuzz-dhcp-server.c',
-          ],
+
+        [['src/fuzz/fuzz-dhcp-server.c'],
          [libsystemd_network,
           libshared],
-          []]
+         []],
+
+        [['src/fuzz/fuzz-unit-file.c'],
+         [libcore,
+          libshared],
+         [libmount]],
 ]