From ae6636a28facf19db6b146a4f8a93908de6a1242 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tim=20R=C3=BChsen?= <tim.ruehsen@gmx.de>
Date: Sun, 3 Mar 2019 17:05:58 +0100
Subject: [PATCH] * fuzz/wget_netrc_fuzzer.c: Fix fuzzer

---
 fuzz/wget_netrc_fuzzer.c | 34 +++++++++++++++++++++++++++++++---
 1 file changed, 31 insertions(+), 3 deletions(-)

diff --git a/fuzz/wget_netrc_fuzzer.c b/fuzz/wget_netrc_fuzzer.c
index 631c3d5e..b0d1c0fb 100644
--- a/fuzz/wget_netrc_fuzzer.c
+++ b/fuzz/wget_netrc_fuzzer.c
@@ -58,26 +58,49 @@ FILE *fopen_wgetrc(const char *pathname, const char *mode)
 	return NULL;
 }
 
+static int do_jump;
+static jmp_buf jmpbuf;
 #ifdef FUZZING
 void exit_wget(int status)
 {
+	longjmp(jmpbuf, 1);
+}
+#elif defined HAVE_DLFCN_H
+#include <dlfcn.h> // dlsym
+#ifndef RTLD_NEXT
+#define RTLD_NEXT RTLD_GLOBAL
+#endif
+void exit(int status)
+{
+	if (do_jump) {
+		longjmp(jmpbuf, 1);
+	} else {
+		void (*libc_exit)(int) = (void(*)(int)) dlsym (RTLD_NEXT, "exit");
+		libc_exit(status);
+	}
 }
 #endif
 
 int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
 {
+#ifdef HAVE_FMEMOPEN
 	FILE *fp;
 	struct fileinfo *fi;
-        const char *user = NULL, *pw = NULL;
+	const char *user = NULL, *pw = NULL;
 
 	if (size > 4096) // same as max_len = ... in .options file
 		return 0;
 
-	CLOSE_STDERR
-
 	fp = fmemopen((void *) data, size, "r");
 	if (!fp) return 0;
 
+	CLOSE_STDERR
+
+	do_jump = 1;
+
+	if (setjmp(jmpbuf))
+		goto done;
+
 	opt.netrc = 1;
 
 	user = NULL; // get first entry
@@ -86,11 +109,16 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
 
 	user = "u"; // get entry for user 'u'
 	search_netrc("x", &user, &pw, 1, fp);
+
+done:
 	netrc_cleanup();
 
 	fclose(fp);
 
+	do_jump = 0;
+
 	RESTORE_STDERR
 
+#endif
 	return 0;
 }