1 files changed, 121 insertions, 0 deletions
diff --git a/lib/iolog/regress/fuzz/fuzz_iolog_json.c b/lib/iolog/regress/fuzz/fuzz_iolog_json.c
new file mode 100644
index 0000000..b4cfcaf
--- /dev/null
+++ b/lib/iolog/regress/fuzz/fuzz_iolog_json.c
@@ -0,0 +1,121 @@
+/*
+ * Copyright (c) 2021 Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
+#if defined(HAVE_STDINT_H)
+# include <stdint.h>
+#elif defined(HAVE_INTTYPES_H)
+# include <inttypes.h>
+#endif
+
+#include <sudo_compat.h>
+#include <sudo_debug.h>
+#include <sudo_eventlog.h>
+#include <sudo_fatal.h>
+#include <sudo_iolog.h>
+#include <sudo_plugin.h>
+#include <sudo_util.h>
+
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size);
+
+static FILE *
+open_data(const uint8_t *data, size_t size)
+{
+#ifdef HAVE_FMEMOPEN
+    /* Operate in-memory. */
+    return fmemopen((void *)data, size, "r");
+#else
+    char tempfile[] = "/tmp/json.XXXXXX";
+    size_t nwritten;
+    int fd;
+
+    /* Use (unlinked) temporary file. */
+    fd = mkstemp(tempfile);
+    if (fd == -1)
+	return NULL;
+    unlink(tempfile);
+    nwritten = write(fd, data, size);
+    if (nwritten != size) {
+	close(fd);
+	return NULL;
+    }
+    lseek(fd, 0, SEEK_SET);
+    return fdopen(fd, "r");
+#endif
+}
+
+static int
+fuzz_conversation(int num_msgs, const struct sudo_conv_message msgs[],
+    struct sudo_conv_reply replies[], struct sudo_conv_callback *callback)
+{
+    int n;
+
+    for (n = 0; n < num_msgs; n++) {
+	const struct sudo_conv_message *msg = &msgs[n];
+
+	switch (msg->msg_type & 0xff) {
+	    case SUDO_CONV_PROMPT_ECHO_ON:
+	    case SUDO_CONV_PROMPT_MASK:
+	    case SUDO_CONV_PROMPT_ECHO_OFF:
+		/* input not supported */
+		return -1;
+	    case SUDO_CONV_ERROR_MSG:
+	    case SUDO_CONV_INFO_MSG:
+		/* no output for fuzzers */
+		break;
+	    default:
+		return -1;
+	}
+    }
+    return 0;
+}
+
+int
+LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
+{
+    struct eventlog *evlog = NULL;
+    FILE *fp;
+
+    initprogname("fuzz_iolog_json");
+    if (getenv("SUDO_FUZZ_VERBOSE") == NULL)
+	sudo_warn_set_conversation(fuzz_conversation);
+
+    fp = open_data(data, size);
+    if (fp == NULL)
+        return 0;
+
+    /* Parsed contents of an log.json file are stored in evlog. */
+    evlog = calloc(1, sizeof(*evlog));
+    if (evlog != NULL) {
+	evlog->runuid = (uid_t)-1;
+	evlog->rungid = (gid_t)-1;
+	evlog->exit_value = -1;
+
+	/* Try to parse buffer as a JSON-format I/O log info file. */
+	iolog_parse_loginfo_json(fp, "fuzz.json", evlog);
+	eventlog_free(evlog);
+    }
+    fclose(fp);
+
+    fflush(stdout);
+
+    return 0;
+}