/src/libwebp/tests/fuzzer/nalloc.h

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/*
 MIT License

 Copyright (c) 2025 Catena cyber

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 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:

 The above copyright notice and this permission notice shall be included in all
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 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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*/

#ifndef WEBP_TESTS_FUZZER_NALLOC_H_
#define WEBP_TESTS_FUZZER_NALLOC_H_

#if defined(WEBP_FUZZER_ENABLE_NALLOC)

#if defined(__clang__) && defined(__has_feature)
#if __has_feature(address_sanitizer)
#define NALLOC_ASAN 1
#endif
#endif

#include <errno.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#ifdef __cplusplus
extern "C" {
#endif

static const uint32_t nalloc_crc32_table[] = {
    0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b,
    0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
    0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, 0x4c11db70, 0x48d0c6c7,
    0x4593e01e, 0x4152fda9, 0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
    0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3,
    0x709f7b7a, 0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
    0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58, 0xbaea46ef,
    0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
    0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49, 0xc7361b4c, 0xc3f706fb,
    0xceb42022, 0xca753d95, 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
    0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0,
    0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
    0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, 0x018aeb13, 0x054bf6a4,
    0x0808d07d, 0x0cc9cdca, 0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,
    0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08,
    0x571d7dd1, 0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
    0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b, 0xbb60adfc,
    0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,
    0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a, 0xe0b41de7, 0xe4750050,
    0xe9362689, 0xedf73b3e, 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
    0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34,
    0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,
    0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb, 0x4f040d56, 0x4bc510e1,
    0x46863638, 0x42472b8f, 0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
    0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5,
    0x3f9b762c, 0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
    0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e, 0xf5ee4bb9,
    0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
    0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f, 0xc423cd6a, 0xc0e2d0dd,
    0xcda1f604, 0xc960ebb3, 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
    0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71,
    0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
    0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, 0x4e8ee645, 0x4a4ffbf2,
    0x470cdd2b, 0x43cdc09c, 0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,
    0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e,
    0x18197087, 0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
    0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d, 0x2056cd3a,
    0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,
    0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c, 0xe3a1cbc1, 0xe760d676,
    0xea23f0af, 0xeee2ed18, 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
    0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662,
    0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
    0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4};

// Nallocfuzz data to take a decision
uint32_t nalloc_random_state = 0;
__thread unsigned int nalloc_running = 0;
bool nalloc_initialized = false;
uint32_t nalloc_runs = 0;

// Nalloc fuzz parameters
uint32_t nalloc_bitmask = 0xFF;
bool nalloc_random_bitmask = true;
uint32_t nalloc_magic = 0x294cee63;
bool nalloc_verbose = false;

#ifdef NALLOC_ASAN
extern void __sanitizer_print_stack_trace(void);
#endif

// Generic init, using env variables to get parameters
void nalloc_init(const char* prog) {
  if (nalloc_initialized) {
    return;
  }
  nalloc_initialized = true;
  char* bitmask = getenv("NALLOC_FREQ");
  if (bitmask) {
    int shift = atoi(bitmask);
    if (shift > 0 && shift < 31) {
      nalloc_bitmask = 1 << shift;
      nalloc_random_bitmask = false;
    } else if (shift == 0) {
      nalloc_random_bitmask = false;
      nalloc_bitmask = 0;
    }
  } else if (prog == NULL || strstr(prog, "nalloc") == NULL) {
    nalloc_random_bitmask = false;
    nalloc_bitmask = 0;
    return;
  }

  char* magic = getenv("NALLOC_MAGIC");
  if (magic) {
    nalloc_magic = (uint32_t)strtol(magic, NULL, 0);
  }

  char* verbose = getenv("NALLOC_VERBOSE");
  if (verbose) {
    nalloc_verbose = true;
  }
}

// add one byte to the CRC
static inline void nalloc_random_update(uint8_t b) {
  nalloc_random_state =
      ((uint32_t)((uint32_t)nalloc_random_state << 8)) ^
      nalloc_crc32_table[((nalloc_random_state >> 24) ^ b) & 0xFF];
}

// Start the failure injections, using a buffer as seed
static int nalloc_start(const uint8_t* data, size_t size) {
  if (nalloc_random_bitmask) {
    if (nalloc_random_state & 0x10) {
      nalloc_bitmask = 0xFFFFFFFF;
    } else {
      nalloc_bitmask = 1 << (5 + (nalloc_random_state & 0xF));
    }
  } else if (nalloc_bitmask == 0) {
    // nalloc disabled
    return 0;
  }
  nalloc_random_state = 0;
  for (size_t i = 0; i < size; i++) {
    nalloc_random_update(data[i]);
  }
  if (__sync_fetch_and_add(&nalloc_running, 1)) {
    __sync_fetch_and_sub(&nalloc_running, 1);
    return 0;
  }
  nalloc_runs++;
  return 1;
}

// Stop the failure injections
static void nalloc_end() { __sync_fetch_and_sub(&nalloc_running, 1); }

static bool nalloc_backtrace_exclude(size_t size, const char* op) {
  if (nalloc_verbose) {
    fprintf(stderr, "failed %s(%zu) \n", op, size);
#ifdef NALLOC_ASAN
    __sanitizer_print_stack_trace();
#endif
  }

  return false;
}

//
static bool nalloc_fail(size_t size, const char* op) {
  // do not fail before thread init
  if (nalloc_runs == 0) {
    return false;
  }
  if (__sync_fetch_and_add(&nalloc_running, 1) != 1) {
    // do not fail allocations outside of fuzzer input
    // and do not fail inside of this function
    __sync_fetch_and_sub(&nalloc_running, 1);
    return false;
  }
  nalloc_random_update((uint8_t)size);
  if (size >= 0x100) {
    nalloc_random_update((uint8_t)(size >> 8));
    if (size >= 0x10000) {
      nalloc_random_update((uint8_t)(size >> 16));
      // bigger may already fail or oom
    }
  }
  if (((nalloc_random_state ^ nalloc_magic) & nalloc_bitmask) == 0) {
    if (nalloc_backtrace_exclude(size, op)) {
      __sync_fetch_and_sub(&nalloc_running, 1);
      return false;
    }
    __sync_fetch_and_sub(&nalloc_running, 1);
    return true;
  }
  __sync_fetch_and_sub(&nalloc_running, 1);
  return false;
}

// ASAN interceptor for libc routines
#ifdef NALLOC_ASAN
extern void* __interceptor_malloc(size_t);
extern void* __interceptor_calloc(size_t, size_t);
extern void* __interceptor_realloc(void*, size_t);
extern void* __interceptor_reallocarray(void*, size_t, size_t);

extern ssize_t __interceptor_read(int, void*, size_t);
extern ssize_t __interceptor_write(int, const void*, size_t);
extern ssize_t __interceptor_recv(int, void*, size_t, int);
extern ssize_t __interceptor_send(int, const void*, size_t, int);

#define nalloc_malloc(s) __interceptor_malloc(s)
#define nalloc_calloc(s, n) __interceptor_calloc(s, n)
#define nalloc_realloc(p, s) __interceptor_realloc(p, s)
#define nalloc_reallocarray(p, s, n) __interceptor_reallocarray(p, s, n)

#define nalloc_read(f, b, s) __interceptor_read(f, b, s)
#define nalloc_write(f, b, s) __interceptor_write(f, b, s)
#define nalloc_recv(f, b, s, x) __interceptor_recv(f, b, s, x)
#define nalloc_send(f, b, s, x) __interceptor_send(f, b, s, x)

#else
extern void* __libc_malloc(size_t);
extern void* __libc_calloc(size_t, size_t);
extern void* __libc_realloc(void*, size_t);
extern void* __libc_reallocarray(void*, size_t, size_t);

extern ssize_t __read(int, void*, size_t);
extern ssize_t __write(int, const void*, size_t);
extern ssize_t __recv(int, void*, size_t, int);
extern ssize_t __send(int, const void*, size_t, int);

#define nalloc_malloc(s) __libc_malloc(s)
#define nalloc_calloc(s, n) __libc_calloc(s, n)
#define nalloc_realloc(p, s) __libc_realloc(p, s)
#define nalloc_reallocarray(p, s, n) __libc_reallocarray(p, s, n)

#define nalloc_read(f, b, s) __read(f, b, s)
#define nalloc_write(f, b, s) __write(f, b, s)
#define nalloc_recv(f, b, s, x) __recv(f, b, s, x)
#define nalloc_send(f, b, s, x) __send(f, b, s, x)
#endif

// nalloc standard function overwrites with pseudo-random failures
ssize_t read(int fd, void* buf, size_t count) {
  if (nalloc_fail(count, "read")) {
    errno = EIO;
    return -1;
  }
  return nalloc_read(fd, buf, count);
}

ssize_t write(int fd, const void* buf, size_t count) {
  if (nalloc_fail(count, "write")) {
    errno = EIO;
    return -1;
  }
  return nalloc_write(fd, buf, count);
}

ssize_t recv(int fd, void* buf, size_t count, int flags) {
  if (nalloc_fail(count, "recv")) {
    errno = EIO;
    return -1;
  }
  return nalloc_recv(fd, buf, count, flags);
}

ssize_t send(int fd, const void* buf, size_t count, int flags) {
  if (nalloc_fail(count, "send")) {
    errno = EIO;
    return -1;
  }
  return nalloc_send(fd, buf, count, flags);
}

void* calloc(size_t nmemb, size_t size) {
  if (nalloc_fail(size, "calloc")) {
    errno = ENOMEM;
    return NULL;
  }
  return nalloc_calloc(nmemb, size);
}

void* malloc(size_t size) {
  if (nalloc_fail(size, "malloc")) {
    errno = ENOMEM;
    return NULL;
  }
  return nalloc_malloc(size);
}

void* realloc(void* ptr, size_t size) {
  if (nalloc_fail(size, "realloc")) {
    errno = ENOMEM;
    return NULL;
  }
  return nalloc_realloc(ptr, size);
}

void* reallocarray(void* ptr, size_t nmemb, size_t size) {
  if (nalloc_fail(size, "reallocarray")) {
    errno = ENOMEM;
    return NULL;
  }
  return nalloc_reallocarray(ptr, nmemb, size);
}

#ifdef __cplusplus
}  // extern "C" {
#endif

#else  // defined(WEBP_FUZZER_ENABLE_NALLOC)
#define nalloc_init(x)
#define nalloc_start(x, y)
#define nalloc_end()
#endif  // defined(WEBP_FUZZER_ENABLE_NALLOC)

#endif  // WEBP_TESTS_FUZZER_NALLOC_H_

Coverage Report

Created: 2026-09-04 06:18