fuzz: add generic command argument fuzzer

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
This commit is contained in:
Jason A. Donenfeld 2020-01-04 15:34:28 +01:00
parent 1d2d6200b8
commit cdd8d8ba9f
5 changed files with 82 additions and 5 deletions

2
src/fuzz/.gitignore vendored
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@ -1,2 +1,4 @@
config
uapi
stringlist
cmd

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@ -2,10 +2,10 @@
#
# Copyright (C) 2018-2020 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
all: config uapi stringlist
all: config uapi stringlist cmd
CFLAGS ?= -O3 -march=native -g
CFLAGS += -fsanitize=fuzzer -fsanitize=address -std=gnu11 -idirafter ../uapi
CFLAGS += -fsanitize=fuzzer -fsanitize=address -std=gnu11 -idirafter ../uapi -D_GNU_SOURCE
CC := clang
config: config.c ../config.c ../encoding.c
@ -17,7 +17,10 @@ uapi: uapi.c ../ipc.c ../curve25519.c ../encoding.c
stringlist: stringlist.c ../ipc.c ../curve25519.c ../encoding.c
$(CC) $(CFLAGS) -o $@ $<
cmd: cmd.c $(wildcard ../*.c)
$(CC) $(CFLAGS) -D'RUNSTATEDIR="/var/empty"' -D'main(a,b)=wg_main(a,b)' -o $@ $^ -lmnl
clean:
rm -f config uapi stringlist
rm -f config uapi stringlist cmd
.PHONY: all clean

72
src/fuzz/cmd.c Normal file
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@ -0,0 +1,72 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2018-2020 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*/
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
const char *__asan_default_options()
{
return "verbosity=1";
}
int wg_main(int argc, char *argv[]);
static FILE *devnull;
int LLVMFuzzerTestOneInput(const char *data, size_t data_len)
{
char *argv[8192] = { 0 }, *args;
size_t argc = 0;
FILE *fake_stdin = NULL;
if (!devnull) {
assert((devnull = fopen("/dev/null", "r+")));
stdin = stdout = stderr = devnull;
}
assert((args = malloc(data_len)));
memcpy(args, data, data_len);
if (data_len)
args[data_len - 1] = '\0';
for (const char *arg = args; argc < 8192 && arg - args < data_len; arg += strlen(arg) + 1) {
if (arg[0])
assert((argv[argc++] = strdup(arg)));
}
if (!argc)
assert((argv[argc++] = strdup("no argv[0]!")));
if (argc > 2 && (!strcmp(argv[1], "show") || !strcmp(argv[1], "showconf") || !strcmp(argv[1], "set") || !strcmp(argv[1], "setconf") || !strcmp(argv[1], "addconf") || !strcmp(argv[1], "syncconf"))) {
free(argv[2]);
assert((argv[2] = strdup("wg0")));
}
if (argc >= 2 && !strcmp(argv[1], "pubkey")) {
char *arg;
size_t len;
for (size_t i = 2; i < argc; ++i)
free(argv[i]);
argc = 2;
arg = args;
for (; !arg[0]; ++arg);
arg += strlen(arg) + 1;
for (; !arg[0]; ++arg);
arg += strlen(arg) + 1;
len = data_len - (arg - args);
if (len <= 1)
goto done;
assert((fake_stdin = fmemopen(arg, len - 1, "r")));
stdin = fake_stdin;
}
wg_main(argc, argv);
done:
for (size_t i = 0; i < argc; ++i)
free(argv[i]);
free(args);
if (fake_stdin)
fclose(fake_stdin);
return 0;
}

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@ -4,9 +4,9 @@
*/
#define RUNSTATEDIR "/var/empty"
#include "../curve25519.c"
#undef __linux__
#include "../ipc.c"
#include "../curve25519.c"
#include "../encoding.c"
#include <stdint.h>

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@ -8,9 +8,9 @@
static FILE *hacked_userspace_interface_file(const char *iface);
#define stat(a, b) ({ return hacked_userspace_interface_file(iface); 0; })
#define RUNSTATEDIR "/var/empty"
#include "../curve25519.c"
#undef __linux__
#include "../ipc.c"
#include "../curve25519.c"
#include "../encoding.c"
#include <stdint.h>