/*
american fuzzy lop++ - error-checking, memory-zeroing alloc routines
--------------------------------------------------------------------
Originally written by Michal Zalewski
Now maintained by Marc Heuse <mh@mh-sec.de>,
Heiko Eißfeldt <heiko.eissfeldt@hexco.de> and
Andrea Fioraldi <andreafioraldi@gmail.com>
Copyright 2016, 2017 Google Inc. All rights reserved.
Copyright 2019-2020 AFLplusplus Project. 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 allocator is not designed to resist malicious attackers (the canaries
are small and predictable), but provides a robust and portable way to detect
use-after-free, off-by-one writes, stale pointers, and so on.
*/
#ifndef _HAVE_ALLOC_INL_H
#define _HAVE_ALLOC_INL_H
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "config.h"
#include "types.h"
#include "debug.h"
/* User-facing macro to sprintf() to a dynamically allocated buffer. */
#define alloc_printf(_str...) \
({ \
\
u8* _tmp; \
s32 _len = snprintf(NULL, 0, _str); \
if (_len < 0) FATAL("Whoa, snprintf() fails?!"); \
_tmp = ck_alloc(_len + 1); \
snprintf((char*)_tmp, _len + 1, _str); \
_tmp; \
\
})
/* Macro to enforce allocation limits as a last-resort defense against
integer overflows. */
#define ALLOC_CHECK_SIZE(_s) \
do { \
\
if ((_s) > MAX_ALLOC) ABORT("Bad alloc request: %u bytes", (_s)); \
\
} while (0)
/* Macro to check malloc() failures and the like. */
#define ALLOC_CHECK_RESULT(_r, _s) \
do { \
\
if (!(_r)) ABORT("Out of memory: can't allocate %u bytes", (_s)); \
\
} while (0)
/* Allocator increments for ck_realloc_block(). */
#define ALLOC_BLK_INC 256
/* Allocate a buffer, explicitly not zeroing it. Returns NULL for zero-sized
requests. */
static inline void* DFL_ck_alloc_nozero(u32 size) {
u8* ret;
if (!size) return NULL;
ALLOC_CHECK_SIZE(size);
ret = malloc(size);
ALLOC_CHECK_RESULT(ret, size);
return (void*)ret;
}
/* Allocate a buffer, returning zeroed memory. */
static inline void* DFL_ck_alloc(u32 size) {
void* mem;
if (!size) return NULL;
mem = DFL_ck_alloc_nozero(size);
return memset(mem, 0, size);
}
/* Free memory */
static inline void DFL_ck_free(void* mem) {
free(mem);
}
/* Re-allocate a buffer, checking for issues and zeroing any newly-added tail.
With DEBUG_BUILD, the buffer is always reallocated to a new addresses and the
old memory is clobbered with 0xFF. */
static inline void* DFL_ck_realloc(void* orig, u32 size) {
u8* ret;
u32 old_size = 0;
if (!size) {
DFL_ck_free(orig);
return NULL;
}
ALLOC_CHECK_SIZE(size);
ret = realloc(orig, size);
ALLOC_CHECK_RESULT(ret, size);
if (size > old_size) memset(ret + old_size, 0, size - old_size);
return (void*)ret;
}
/* Re-allocate a buffer with ALLOC_BLK_INC increments (used to speed up
repeated small reallocs without complicating the user code). */
static inline void* DFL_ck_realloc_block(void* orig, u32 size) {
if (orig) size += ALLOC_BLK_INC;
return DFL_ck_realloc(orig, size);
}
/* Create a buffer with a copy of a string. Returns NULL for NULL inputs. */
static inline u8* DFL_ck_strdup(u8* str) {
u8* ret;
u32 size;
if (!str) return NULL;
size = strlen((char*)str) + 1;
ALLOC_CHECK_SIZE(size);
ret = malloc(size);
ALLOC_CHECK_RESULT(ret, size);
return memcpy(ret, str, size);
}
/* Create a buffer with a copy of a memory block. Returns NULL for zero-sized
or NULL inputs. */
static inline void* DFL_ck_memdup(void* mem, u32 size) {
u8* ret;
if (!mem || !size) return NULL;
ALLOC_CHECK_SIZE(size);
ret = malloc(size);
ALLOC_CHECK_RESULT(ret, size);
return memcpy(ret, mem, size);
}
/* Create a buffer with a block of text, appending a NUL terminator at the end.
Returns NULL for zero-sized or NULL inputs. */
static inline u8* DFL_ck_memdup_str(u8* mem, u32 size) {
u8* ret;
if (!mem || !size) return NULL;
ALLOC_CHECK_SIZE(size);
ret = malloc(size + 1);
ALLOC_CHECK_RESULT(ret, size);
memcpy(ret, mem, size);
ret[size] = 0;
return ret;
}
/* In non-debug mode, we just do straightforward aliasing of the above functions
to user-visible names such as ck_alloc(). */
#define ck_alloc DFL_ck_alloc
#define ck_alloc_nozero DFL_ck_alloc_nozero
#define ck_realloc DFL_ck_realloc
#define ck_realloc_block DFL_ck_realloc_block
#define ck_strdup DFL_ck_strdup
#define ck_memdup DFL_ck_memdup
#define ck_memdup_str DFL_ck_memdup_str
#define ck_free DFL_ck_free
#define alloc_report()
#endif /* ! _HAVE_ALLOC_INL_H */
