libcompcov for QEMU

.gitignore

@@ -1,4 +1,5 @@
 *.o
+*.so
 .gitignore
 afl-analyze
 afl-as

qemu_mode/libcompcov/Makefile

@@ -0,0 +1,38 @@
+#
+# american fuzzy lop - libcompcov
+# --------------------------------
+#
+# Written by Andrea Fioraldi <andreafioraldi@gmail.com>
+#
+# Copyright 2019 Andrea Fioraldi. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+
+PREFIX      ?= /usr/local
+HELPER_PATH  = $(PREFIX)/lib/afl
+
+VERSION     = $(shell grep '^\#define VERSION ' ../config.h | cut -d '"' -f2)
+
+CFLAGS      ?= -O3 -funroll-loops
+CFLAGS      += -Wall -Wno-unused-result -D_FORTIFY_SOURCE=2 -g -Wno-pointer-sign
+
+all: libcompcov.so
+
+libcompcov.so: libcompcov.so.c ../../config.h
+	$(CC) $(CFLAGS) -shared -fPIC $< -o $@ $(LDFLAGS)
+
+.NOTPARALLEL: clean
+
+clean:
+	rm -f *.o *.so *~ a.out core core.[1-9][0-9]*
+	rm -f libcompcov.so
+
+install: all
+	install -m 755 libcompcov.so $${DESTDIR}$(HELPER_PATH)
+	install -m 644 README.compcov $${DESTDIR}$(HELPER_PATH)
+

qemu_mode/libcompcov/README.compcov

@@ -0,0 +1,33 @@
+================================================================
+strcmp() / memcmp() CompareCoverage library for AFLplusplus-QEMU
+================================================================
+
+  Written by Andrea Fioraldi <andreafioraldi@gmail.com>
+
+This Linux-only companion library allows you to instrument strcmp(), memcmp(),
+and related functions to log the CompareCoverage of these libcalls.
+
+Use this with caution. While this can speedup a lot the bypass of hard
+branch conditions it can also waste a lot of time and take up unnecessary space
+in the shared memory when logging the coverage related to functions that
+doesn't process input-related data.
+
+To use the library, you *need* to make sure that your fuzzing target is linked
+dynamically and make use of strcmp(), memcmp(), and related functions.
+For optimized binaries this is an issue, those functions are often inlined
+and this module is not capable to log the coverage in this case.
+
+If you have the source code of the fuzzing target you should nto use this
+library and QEMU but build ot with afl-clang-fast and the laf-intel options.
+
+To use this library make sure to preload it with AFL_PRELOAD.
+
+  export AFL_PRELOAD=/path/to/libcompcov.so
+  export AFL_QEMU_COMPCOV=1
+  
+  afl-fuzz -Q -i input -o output <your options> -- <target args>
+
+The library make use of https://github.com/ouadev/proc_maps_parser and so it is
+Linux specific. However this is not a strict dependency, other UNIX operating
+systems can be supported simply replacing the code related to the
+/proc/self/maps parsing.

qemu_mode/libcompcov/libcompcov.so.c

@@ -0,0 +1,307 @@
+/*
+
+   american fuzzy lop++ - strcmp() / memcmp() CompareCoverage library
+   ------------------------------------------------------------------
+
+   Written and maintained by Andrea Fioraldi <andreafioraldi@gmail.com>
+
+   Copyright 2019 Andrea Fioraldi. All rights reserved.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at:
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+   This Linux-only companion library allows you to instrument strcmp(),
+   memcmp(), and related functions to get compare coverage.
+   See README.compcov for more info.
+
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <sys/types.h>
+#include <sys/shm.h>
+
+#include "../../types.h"
+#include "../../config.h"
+
+#include "pmparser.h"
+
+#ifndef __linux__
+#  error "Sorry, this library is Linux-specific for now!"
+#endif /* !__linux__ */
+
+/* Change this value to tune the compare coverage */
+
+#define MAX_CMP_LENGTH 32
+
+static u8 __compcov_loaded;
+
+static void *__compcov_code_start,
+            *__compcov_code_end;
+
+static u8 *__compcov_afl_map;
+
+
+static size_t __strlen2(const char *s1, const char *s2, size_t max_length) {
+  // from https://github.com/googleprojectzero/CompareCoverage
+  
+  size_t len = 0;
+  for (; len < max_length && s1[len] != '\0' && s2[len] != '\0'; len++) { }
+  return len;
+}
+
+/* Identify the binary boundaries in the memory mapping */
+
+static void __compcov_load(void) {
+
+  __compcov_loaded = 1;
+  
+  char *id_str = getenv(SHM_ENV_VAR);
+  int shm_id;
+
+  if (id_str) {
+
+    shm_id = atoi(id_str);
+    __compcov_afl_map = shmat(shm_id, NULL, 0);
+
+    if (__compcov_afl_map == (void*)-1) exit(1);
+  } else {
+  
+    __compcov_afl_map = calloc(1, MAP_SIZE);
+  }
+
+  if (getenv("AFL_INST_LIBS")) {
+  
+    __compcov_code_start = (void*)0;
+    __compcov_code_end = (void*)-1;
+    return;
+  }
+
+  char* bin_name = getenv("AFL_COMPCOV_BINNAME");
+
+  procmaps_iterator* maps = pmparser_parse(-1);
+  procmaps_struct* maps_tmp = NULL;
+
+  while ((maps_tmp = pmparser_next(maps)) != NULL) {
+  
+    /* If AFL_COMPCOV_BINNAME is not set pick the first executable segment */
+    if (!bin_name || strstr(maps_tmp->pathname, bin_name) != NULL) {
+    
+      if (maps_tmp->is_x) {
+        if (!__compcov_code_start)
+            __compcov_code_start = maps_tmp->addr_start;
+        if (!__compcov_code_end)
+            __compcov_code_end = maps_tmp->addr_end;
+      }
+    }
+  }
+
+  pmparser_free(maps);
+}
+
+
+static void __compcov_trace(u64 cur_loc, const u8* v0, const u8* v1, size_t n) {
+
+  size_t i;
+  
+  for (i = 0; i < n && v0[i] == v1[i]; ++i) {
+  
+    __compcov_afl_map[cur_loc +i]++;
+  }
+}
+
+/* Check an address against the list of read-only mappings. */
+
+static u8 __compcov_is_in_bound(const void* ptr) {
+
+  return ptr >= __compcov_code_start && ptr < __compcov_code_end;
+}
+
+
+/* Replacements for strcmp(), memcmp(), and so on. Note that these will be used
+   only if the target is compiled with -fno-builtins and linked dynamically. */
+
+#undef strcmp
+
+int strcmp(const char* str1, const char* str2) {
+
+  void* retaddr = __builtin_return_address(0);
+  
+  if (__compcov_is_in_bound(retaddr)) {
+
+    size_t n = __strlen2(str1, str2, MAX_CMP_LENGTH +1);
+    
+    if (n <= MAX_CMP_LENGTH) {
+    
+      u64 cur_loc = (u64)retaddr;
+      cur_loc  = (cur_loc >> 4) ^ (cur_loc << 8);
+      cur_loc &= MAP_SIZE - 1;
+      
+      __compcov_trace(cur_loc, str1, str2, n);
+    }
+  }
+
+  while (1) {
+
+    unsigned char c1 = *str1, c2 = *str2;
+
+    if (c1 != c2) return (c1 > c2) ? 1 : -1;
+    if (!c1) return 0;
+    str1++; str2++;
+
+  }
+
+}
+
+
+#undef strncmp
+
+int strncmp(const char* str1, const char* str2, size_t len) {
+
+  void* retaddr = __builtin_return_address(0);
+  
+  if (__compcov_is_in_bound(retaddr)) {
+
+    size_t n = __strlen2(str1, str2, MAX_CMP_LENGTH +1);
+    n = MIN(n, len);
+    
+    if (n <= MAX_CMP_LENGTH) {
+    
+      u64 cur_loc = (u64)retaddr;
+      cur_loc  = (cur_loc >> 4) ^ (cur_loc << 8);
+      cur_loc &= MAP_SIZE - 1;
+      
+      __compcov_trace(cur_loc, str1, str2, n);
+    }
+  }
+  
+  while (len--) {
+
+    unsigned char c1 = *str1, c2 = *str2;
+
+    if (!c1) return 0;
+    if (c1 != c2) return (c1 > c2) ? 1 : -1;
+    str1++; str2++;
+
+  }
+
+  return 0;
+
+}
+
+
+#undef strcasecmp
+
+int strcasecmp(const char* str1, const char* str2) {
+
+  void* retaddr = __builtin_return_address(0);
+  
+  if (__compcov_is_in_bound(retaddr)) {
+    /* Fallback to strcmp, maybe improve in future */
+
+    size_t n = __strlen2(str1, str2, MAX_CMP_LENGTH +1);
+    
+    if (n <= MAX_CMP_LENGTH) {
+    
+      u64 cur_loc = (u64)retaddr;
+      cur_loc  = (cur_loc >> 4) ^ (cur_loc << 8);
+      cur_loc &= MAP_SIZE - 1;
+      
+      __compcov_trace(cur_loc, str1, str2, n);
+    }
+  }
+
+  while (1) {
+
+    unsigned char c1 = tolower(*str1), c2 = tolower(*str2);
+
+    if (c1 != c2) return (c1 > c2) ? 1 : -1;
+    if (!c1) return 0;
+    str1++; str2++;
+
+  }
+
+}
+
+
+#undef strncasecmp
+
+int strncasecmp(const char* str1, const char* str2, size_t len) {
+
+  void* retaddr = __builtin_return_address(0);
+  
+  if (__compcov_is_in_bound(retaddr)) {
+    /* Fallback to strncmp, maybe improve in future */
+
+    size_t n = __strlen2(str1, str2, MAX_CMP_LENGTH +1);
+    n = MIN(n, len);
+    
+    if (n <= MAX_CMP_LENGTH) {
+    
+      u64 cur_loc = (u64)retaddr;
+      cur_loc  = (cur_loc >> 4) ^ (cur_loc << 8);
+      cur_loc &= MAP_SIZE - 1;
+      
+      __compcov_trace(cur_loc, str1, str2, n);
+    }
+  }
+
+  while (len--) {
+
+    unsigned char c1 = tolower(*str1), c2 = tolower(*str2);
+
+    if (!c1) return 0;
+    if (c1 != c2) return (c1 > c2) ? 1 : -1;
+    str1++; str2++;
+
+  }
+
+  return 0;
+
+}
+
+
+#undef memcmp
+
+int memcmp(const void* mem1, const void* mem2, size_t len) {
+
+  void* retaddr = __builtin_return_address(0);
+  
+  if (__compcov_is_in_bound(retaddr)) {
+
+    size_t n = len;
+    
+    if (n <= MAX_CMP_LENGTH) {
+    
+      u64 cur_loc = (u64)retaddr;
+      cur_loc  = (cur_loc >> 4) ^ (cur_loc << 8);
+      cur_loc &= MAP_SIZE - 1;
+      
+      __compcov_trace(cur_loc, mem1, mem2, n);
+    }
+  }
+
+  while (len--) {
+
+    unsigned char c1 = *(const char*)mem1, c2 = *(const char*)mem2;
+    if (c1 != c2) return (c1 > c2) ? 1 : -1;
+    mem1++; mem2++;
+
+  }
+
+  return 0;
+
+}
+
+/* Init code to open init the library. */
+
+__attribute__((constructor)) void __compcov_init(void) {
+
+  __compcov_load();
+}
+
+

qemu_mode/libcompcov/pmparser.h

@@ -0,0 +1,280 @@
+/*
+ @Author	: ouadimjamal@gmail.com
+ @date		: December 2015
+
+Permission to use, copy, modify, distribute, and sell this software and its
+documentation for any purpose is hereby granted without fee, provided that
+the above copyright notice appear in all copies and that both that
+copyright notice and this permission notice appear in supporting
+documentation.  No representations are made about the suitability of this
+software for any purpose.  It is provided "as is" without express or
+implied warranty.
+
+ */
+
+#ifndef H_PMPARSER
+#define H_PMPARSER
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <linux/limits.h>
+
+//maximum line length in a procmaps file
+#define PROCMAPS_LINE_MAX_LENGTH  (PATH_MAX + 100) 
+/**
+ * procmaps_struct
+ * @desc hold all the information about an area in the process's  VM
+ */
+typedef struct procmaps_struct{
+	void* addr_start; 	//< start address of the area
+	void* addr_end; 	//< end address
+	unsigned long length; //< size of the range
+
+	char perm[5];		//< permissions rwxp
+	short is_r;			//< rewrote of perm with short flags
+	short is_w;
+	short is_x;
+	short is_p;
+
+	long offset;	//< offset
+	char dev[12];	//< dev major:minor
+	int inode;		//< inode of the file that backs the area
+
+	char pathname[600];		//< the path of the file that backs the area
+	//chained list
+	struct procmaps_struct* next;		//<handler of the chinaed list
+} procmaps_struct;
+
+/**
+ * procmaps_iterator
+ * @desc holds iterating information
+ */
+typedef struct procmaps_iterator{
+	procmaps_struct* head;
+	procmaps_struct* current;
+} procmaps_iterator;
+/**
+ * pmparser_parse
+ * @param pid the process id whose memory map to be parser. the current process if pid<0
+ * @return an iterator over all the nodes
+ */
+procmaps_iterator* pmparser_parse(int pid);
+
+/**
+ * pmparser_next
+ * @description move between areas
+ * @param p_procmaps_it the iterator to move on step in the chained list
+ * @return a procmaps structure filled with information about this VM area
+ */
+procmaps_struct* pmparser_next(procmaps_iterator* p_procmaps_it);
+/**
+ * pmparser_free
+ * @description should be called at the end to free the resources
+ * @param p_procmaps_it the iterator structure returned by pmparser_parse
+ */
+void pmparser_free(procmaps_iterator* p_procmaps_it);
+
+/**
+ * _pmparser_split_line
+ * @description internal usage
+ */
+void _pmparser_split_line(char*buf,char*addr1,char*addr2,char*perm, char* offset, char* device,char*inode,char* pathname);
+
+/**
+ * pmparser_print
+ * @param map the head of the list
+ * @order the order of the area to print, -1 to print everything
+ */
+void pmparser_print(procmaps_struct* map,int order);
+
+
+/**
+ * gobal variables
+ */
+//procmaps_struct* g_last_head=NULL;
+//procmaps_struct* g_current=NULL;
+
+
+procmaps_iterator* pmparser_parse(int pid){
+	procmaps_iterator* maps_it = malloc(sizeof(procmaps_iterator));
+	char maps_path[500];
+	if(pid>=0 ){
+		sprintf(maps_path,"/proc/%d/maps",pid);
+	}else{
+		sprintf(maps_path,"/proc/self/maps");
+	}
+	FILE* file=fopen(maps_path,"r");
+	if(!file){
+		fprintf(stderr,"pmparser : cannot open the memory maps, %s\n",strerror(errno));
+		return NULL;
+	}
+	int ind=0;char buf[PROCMAPS_LINE_MAX_LENGTH];
+	//int c;
+	procmaps_struct* list_maps=NULL;
+	procmaps_struct* tmp;
+	procmaps_struct* current_node=list_maps;
+	char addr1[20],addr2[20], perm[8], offset[20], dev[10],inode[30],pathname[PATH_MAX];
+	while( !feof(file) ){
+		fgets(buf,PROCMAPS_LINE_MAX_LENGTH,file);
+		//allocate a node
+		tmp=(procmaps_struct*)malloc(sizeof(procmaps_struct));
+		//fill the node
+		_pmparser_split_line(buf,addr1,addr2,perm,offset, dev,inode,pathname);
+		//printf("#%s",buf);
+		//printf("%s-%s %s %s %s %s\t%s\n",addr1,addr2,perm,offset,dev,inode,pathname);
+		//addr_start & addr_end
+		//unsigned long l_addr_start;
+		sscanf(addr1,"%lx",(long unsigned *)&tmp->addr_start );
+		sscanf(addr2,"%lx",(long unsigned *)&tmp->addr_end );
+		//size
+		tmp->length=(unsigned long)(tmp->addr_end-tmp->addr_start);
+		//perm
+		strcpy(tmp->perm,perm);
+		tmp->is_r=(perm[0]=='r');
+		tmp->is_w=(perm[1]=='w');
+		tmp->is_x=(perm[2]=='x');
+		tmp->is_p=(perm[3]=='p');
+
+		//offset
+		sscanf(offset,"%lx",&tmp->offset );
+		//device
+		strcpy(tmp->dev,dev);
+		//inode
+		tmp->inode=atoi(inode);
+		//pathname
+		strcpy(tmp->pathname,pathname);
+		tmp->next=NULL;
+		//attach the node
+		if(ind==0){
+			list_maps=tmp;
+			list_maps->next=NULL;
+			current_node=list_maps;
+		}
+		current_node->next=tmp;
+		current_node=tmp;
+		ind++;
+		//printf("%s",buf);
+	}
+
+	//close file
+	fclose(file);
+
+
+	//g_last_head=list_maps;
+	maps_it->head = list_maps;
+	maps_it->current =  list_maps;
+	return maps_it;
+}
+
+
+procmaps_struct* pmparser_next(procmaps_iterator* p_procmaps_it){
+	if(p_procmaps_it->current == NULL)
+		return NULL;
+	procmaps_struct* p_current = p_procmaps_it->current;
+	p_procmaps_it->current = p_procmaps_it->current->next;
+	return p_current;
+	/*
+	if(g_current==NULL){
+		g_current=g_last_head;
+	}else
+		g_current=g_current->next;
+
+	return g_current;
+	*/
+}
+
+
+
+void pmparser_free(procmaps_iterator* p_procmaps_it){
+	procmaps_struct* maps_list = p_procmaps_it->head;
+	if(maps_list==NULL) return ;
+	procmaps_struct* act=maps_list;
+	procmaps_struct* nxt=act->next;
+	while(act!=NULL){
+		free(act);
+		act=nxt;
+		if(nxt!=NULL)
+			nxt=nxt->next;
+	}
+
+}
+
+
+void _pmparser_split_line(
+		char*buf,char*addr1,char*addr2,
+		char*perm,char* offset,char* device,char*inode,
+		char* pathname){
+	//
+	int orig=0;
+	int i=0;
+	//addr1
+	while(buf[i]!='-'){
+		addr1[i-orig]=buf[i];
+		i++;
+	}
+	addr1[i]='\0';
+	i++;
+	//addr2
+	orig=i;
+	while(buf[i]!='\t' && buf[i]!=' '){
+		addr2[i-orig]=buf[i];
+		i++;
+	}
+	addr2[i-orig]='\0';
+
+	//perm
+	while(buf[i]=='\t' || buf[i]==' ')
+		i++;
+	orig=i;
+	while(buf[i]!='\t' && buf[i]!=' '){
+		perm[i-orig]=buf[i];
+		i++;
+	}
+	perm[i-orig]='\0';
+	//offset
+	while(buf[i]=='\t' || buf[i]==' ')
+		i++;
+	orig=i;
+	while(buf[i]!='\t' && buf[i]!=' '){
+		offset[i-orig]=buf[i];
+		i++;
+	}
+	offset[i-orig]='\0';
+	//dev
+	while(buf[i]=='\t' || buf[i]==' ')
+		i++;
+	orig=i;
+	while(buf[i]!='\t' && buf[i]!=' '){
+		device[i-orig]=buf[i];
+		i++;
+	}
+	device[i-orig]='\0';
+	//inode
+	while(buf[i]=='\t' || buf[i]==' ')
+		i++;
+	orig=i;
+	while(buf[i]!='\t' && buf[i]!=' '){
+		inode[i-orig]=buf[i];
+		i++;
+	}
+	inode[i-orig]='\0';
+	//pathname
+	pathname[0]='\0';
+	while(buf[i]=='\t' || buf[i]==' ')
+		i++;
+	orig=i;
+	while(buf[i]!='\t' && buf[i]!=' ' && buf[i]!='\n'){
+		pathname[i-orig]=buf[i];
+		i++;
+	}
+	pathname[i-orig]='\0';
+
+}
+
+
+#endif