blob: 217bd35c1c541968ee188c320aa8c1ff5c905a92 [file] [log] [blame]
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//===-- dfsan_custom.cpp --------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file is a part of DataFlowSanitizer.
//
// This file defines the custom functions listed in done_abilist.txt.
//===----------------------------------------------------------------------===//
#include <arpa/inet.h>
#include <assert.h>
#include <ctype.h>
#include <dlfcn.h>
#include <link.h>
#include <poll.h>
#include <pthread.h>
#include <pwd.h>
#include <sched.h>
#include <signal.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/epoll.h>
#include <sys/resource.h>
#include <sys/select.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>
#include "dfsan/dfsan.h"
#include "dfsan/dfsan_chained_origin_depot.h"
#include "dfsan/dfsan_flags.h"
#include "dfsan/dfsan_thread.h"
#include "sanitizer_common/sanitizer_common.h"
#include "sanitizer_common/sanitizer_internal_defs.h"
#include "sanitizer_common/sanitizer_linux.h"
#include "sanitizer_common/sanitizer_stackdepot.h"
using namespace __dfsan;
#define CALL_WEAK_INTERCEPTOR_HOOK(f, ...) \
do { \
if (f) \
f(__VA_ARGS__); \
} while (false)
#define DECLARE_WEAK_INTERCEPTOR_HOOK(f, ...) \
SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE void f(__VA_ARGS__);
// Async-safe, non-reentrant spin lock.
class SignalSpinLocker {
public:
SignalSpinLocker() {
sigset_t all_set;
sigfillset(&all_set);
pthread_sigmask(SIG_SETMASK, &all_set, &saved_thread_mask_);
sigactions_mu.Lock();
}
~SignalSpinLocker() {
sigactions_mu.Unlock();
pthread_sigmask(SIG_SETMASK, &saved_thread_mask_, nullptr);
}
private:
static StaticSpinMutex sigactions_mu;
sigset_t saved_thread_mask_;
SignalSpinLocker(const SignalSpinLocker &) = delete;
SignalSpinLocker &operator=(const SignalSpinLocker &) = delete;
};
StaticSpinMutex SignalSpinLocker::sigactions_mu;
extern "C" {
SANITIZER_INTERFACE_ATTRIBUTE int
__dfsw_stat(const char *path, struct stat *buf, dfsan_label path_label,
dfsan_label buf_label, dfsan_label *ret_label) {
int ret = stat(path, buf);
if (ret == 0)
dfsan_set_label(0, buf, sizeof(struct stat));
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfso_stat(
const char *path, struct stat *buf, dfsan_label path_label,
dfsan_label buf_label, dfsan_label *ret_label, dfsan_origin path_origin,
dfsan_origin buf_origin, dfsan_origin *ret_origin) {
int ret = __dfsw_stat(path, buf, path_label, buf_label, ret_label);
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_fstat(int fd, struct stat *buf,
dfsan_label fd_label,
dfsan_label buf_label,
dfsan_label *ret_label) {
int ret = fstat(fd, buf);
if (ret == 0)
dfsan_set_label(0, buf, sizeof(struct stat));
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfso_fstat(
int fd, struct stat *buf, dfsan_label fd_label, dfsan_label buf_label,
dfsan_label *ret_label, dfsan_origin fd_origin, dfsan_origin buf_origin,
dfsan_origin *ret_origin) {
int ret = __dfsw_fstat(fd, buf, fd_label, buf_label, ret_label);
return ret;
}
static char *dfsan_strchr_with_label(const char *s, int c, size_t *bytes_read,
dfsan_label s_label, dfsan_label c_label,
dfsan_label *ret_label) {
char *match_pos = nullptr;
for (size_t i = 0;; ++i) {
if (s[i] == c || s[i] == 0) {
// If s[i] is the \0 at the end of the string, and \0 is not the
// character we are searching for, then return null.
*bytes_read = i + 1;
match_pos = s[i] == 0 && c != 0 ? nullptr : const_cast<char *>(s + i);
break;
}
}
if (flags().strict_data_dependencies)
*ret_label = s_label;
else
*ret_label = dfsan_union(dfsan_read_label(s, *bytes_read),
dfsan_union(s_label, c_label));
return match_pos;
}
SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strchr(const char *s, int c,
dfsan_label s_label,
dfsan_label c_label,
dfsan_label *ret_label) {
size_t bytes_read;
return dfsan_strchr_with_label(s, c, &bytes_read, s_label, c_label,
ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE char *__dfso_strchr(
const char *s, int c, dfsan_label s_label, dfsan_label c_label,
dfsan_label *ret_label, dfsan_origin s_origin, dfsan_origin c_origin,
dfsan_origin *ret_origin) {
size_t bytes_read;
char *r =
dfsan_strchr_with_label(s, c, &bytes_read, s_label, c_label, ret_label);
if (flags().strict_data_dependencies) {
*ret_origin = s_origin;
} else if (*ret_label) {
dfsan_origin o = dfsan_read_origin_of_first_taint(s, bytes_read);
*ret_origin = o ? o : (s_label ? s_origin : c_origin);
}
return r;
}
SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strpbrk(const char *s,
const char *accept,
dfsan_label s_label,
dfsan_label accept_label,
dfsan_label *ret_label) {
const char *ret = strpbrk(s, accept);
if (flags().strict_data_dependencies) {
*ret_label = ret ? s_label : 0;
} else {
size_t s_bytes_read = (ret ? ret - s : strlen(s)) + 1;
*ret_label =
dfsan_union(dfsan_read_label(s, s_bytes_read),
dfsan_union(dfsan_read_label(accept, strlen(accept) + 1),
dfsan_union(s_label, accept_label)));
}
return const_cast<char *>(ret);
}
SANITIZER_INTERFACE_ATTRIBUTE char *__dfso_strpbrk(
const char *s, const char *accept, dfsan_label s_label,
dfsan_label accept_label, dfsan_label *ret_label, dfsan_origin s_origin,
dfsan_origin accept_origin, dfsan_origin *ret_origin) {
const char *ret = __dfsw_strpbrk(s, accept, s_label, accept_label, ret_label);
if (flags().strict_data_dependencies) {
if (ret)
*ret_origin = s_origin;
} else {
if (*ret_label) {
size_t s_bytes_read = (ret ? ret - s : strlen(s)) + 1;
dfsan_origin o = dfsan_read_origin_of_first_taint(s, s_bytes_read);
if (o) {
*ret_origin = o;
} else {
o = dfsan_read_origin_of_first_taint(accept, strlen(accept) + 1);
*ret_origin = o ? o : (s_label ? s_origin : accept_origin);
}
}
}
return const_cast<char *>(ret);
}
static int dfsan_memcmp_bcmp(const void *s1, const void *s2, size_t n,
size_t *bytes_read) {
const char *cs1 = (const char *) s1, *cs2 = (const char *) s2;
for (size_t i = 0; i != n; ++i) {
if (cs1[i] != cs2[i]) {
*bytes_read = i + 1;
return cs1[i] - cs2[i];
}
}
*bytes_read = n;
return 0;
}
static dfsan_label dfsan_get_memcmp_label(const void *s1, const void *s2,
size_t pos) {
if (flags().strict_data_dependencies)
return 0;
return dfsan_union(dfsan_read_label(s1, pos), dfsan_read_label(s2, pos));
}
static void dfsan_get_memcmp_origin(const void *s1, const void *s2, size_t pos,
dfsan_label *ret_label,
dfsan_origin *ret_origin) {
*ret_label = dfsan_get_memcmp_label(s1, s2, pos);
if (*ret_label == 0)
return;
dfsan_origin o = dfsan_read_origin_of_first_taint(s1, pos);
*ret_origin = o ? o : dfsan_read_origin_of_first_taint(s2, pos);
}
static int dfsan_memcmp_bcmp_label(const void *s1, const void *s2, size_t n,
dfsan_label *ret_label) {
size_t bytes_read;
int r = dfsan_memcmp_bcmp(s1, s2, n, &bytes_read);
*ret_label = dfsan_get_memcmp_label(s1, s2, bytes_read);
return r;
}
static int dfsan_memcmp_bcmp_origin(const void *s1, const void *s2, size_t n,
dfsan_label *ret_label,
dfsan_origin *ret_origin) {
size_t bytes_read;
int r = dfsan_memcmp_bcmp(s1, s2, n, &bytes_read);
dfsan_get_memcmp_origin(s1, s2, bytes_read, ret_label, ret_origin);
return r;
}
DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_memcmp, uptr caller_pc,
const void *s1, const void *s2, size_t n,
dfsan_label s1_label, dfsan_label s2_label,
dfsan_label n_label)
DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_origin_memcmp, uptr caller_pc,
const void *s1, const void *s2, size_t n,
dfsan_label s1_label, dfsan_label s2_label,
dfsan_label n_label, dfsan_origin s1_origin,
dfsan_origin s2_origin, dfsan_origin n_origin)
SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_memcmp(const void *s1, const void *s2,
size_t n, dfsan_label s1_label,
dfsan_label s2_label,
dfsan_label n_label,
dfsan_label *ret_label) {
CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_memcmp, GET_CALLER_PC(), s1, s2, n,
s1_label, s2_label, n_label);
return dfsan_memcmp_bcmp_label(s1, s2, n, ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfso_memcmp(
const void *s1, const void *s2, size_t n, dfsan_label s1_label,
dfsan_label s2_label, dfsan_label n_label, dfsan_label *ret_label,
dfsan_origin s1_origin, dfsan_origin s2_origin, dfsan_origin n_origin,
dfsan_origin *ret_origin) {
CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_origin_memcmp, GET_CALLER_PC(), s1,
s2, n, s1_label, s2_label, n_label, s1_origin,
s2_origin, n_origin);
return dfsan_memcmp_bcmp_origin(s1, s2, n, ret_label, ret_origin);
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_bcmp(const void *s1, const void *s2,
size_t n, dfsan_label s1_label,
dfsan_label s2_label,
dfsan_label n_label,
dfsan_label *ret_label) {
return dfsan_memcmp_bcmp_label(s1, s2, n, ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfso_bcmp(
const void *s1, const void *s2, size_t n, dfsan_label s1_label,
dfsan_label s2_label, dfsan_label n_label, dfsan_label *ret_label,
dfsan_origin s1_origin, dfsan_origin s2_origin, dfsan_origin n_origin,
dfsan_origin *ret_origin) {
return dfsan_memcmp_bcmp_origin(s1, s2, n, ret_label, ret_origin);
}
// When n == 0, compare strings without byte limit.
// When n > 0, compare the first (at most) n bytes of s1 and s2.
static int dfsan_strncmp(const char *s1, const char *s2, size_t n,
size_t *bytes_read) {
for (size_t i = 0;; ++i) {
if (s1[i] != s2[i] || s1[i] == 0 || s2[i] == 0 || (n > 0 && i == n - 1)) {
*bytes_read = i + 1;
return s1[i] - s2[i];
}
}
}
DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strcmp, uptr caller_pc,
const char *s1, const char *s2,
dfsan_label s1_label, dfsan_label s2_label)
DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_origin_strcmp, uptr caller_pc,
const char *s1, const char *s2,
dfsan_label s1_label, dfsan_label s2_label,
dfsan_origin s1_origin, dfsan_origin s2_origin)
SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_strcmp(const char *s1, const char *s2,
dfsan_label s1_label,
dfsan_label s2_label,
dfsan_label *ret_label) {
CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strcmp, GET_CALLER_PC(), s1, s2,
s1_label, s2_label);
size_t bytes_read;
int r = dfsan_strncmp(s1, s2, 0, &bytes_read);
*ret_label = dfsan_get_memcmp_label(s1, s2, bytes_read);
return r;
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfso_strcmp(
const char *s1, const char *s2, dfsan_label s1_label, dfsan_label s2_label,
dfsan_label *ret_label, dfsan_origin s1_origin, dfsan_origin s2_origin,
dfsan_origin *ret_origin) {
CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_origin_strcmp, GET_CALLER_PC(), s1,
s2, s1_label, s2_label, s1_origin, s2_origin);
size_t bytes_read;
int r = dfsan_strncmp(s1, s2, 0, &bytes_read);
dfsan_get_memcmp_origin(s1, s2, bytes_read, ret_label, ret_origin);
return r;
}
// When n == 0, compare strings without byte limit.
// When n > 0, compare the first (at most) n bytes of s1 and s2.
static int dfsan_strncasecmp(const char *s1, const char *s2, size_t n,
size_t *bytes_read) {
for (size_t i = 0;; ++i) {
char s1_lower = tolower(s1[i]);
char s2_lower = tolower(s2[i]);
if (s1_lower != s2_lower || s1[i] == 0 || s2[i] == 0 ||
(n > 0 && i == n - 1)) {
*bytes_read = i + 1;
return s1_lower - s2_lower;
}
}
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_strcasecmp(const char *s1,
const char *s2,
dfsan_label s1_label,
dfsan_label s2_label,
dfsan_label *ret_label) {
size_t bytes_read;
int r = dfsan_strncasecmp(s1, s2, 0, &bytes_read);
*ret_label = dfsan_get_memcmp_label(s1, s2, bytes_read);
return r;
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfso_strcasecmp(
const char *s1, const char *s2, dfsan_label s1_label, dfsan_label s2_label,
dfsan_label *ret_label, dfsan_origin s1_origin, dfsan_origin s2_origin,
dfsan_origin *ret_origin) {
size_t bytes_read;
int r = dfsan_strncasecmp(s1, s2, 0, &bytes_read);
dfsan_get_memcmp_origin(s1, s2, bytes_read, ret_label, ret_origin);
return r;
}
DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strncmp, uptr caller_pc,
const char *s1, const char *s2, size_t n,
dfsan_label s1_label, dfsan_label s2_label,
dfsan_label n_label)
DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_origin_strncmp, uptr caller_pc,
const char *s1, const char *s2, size_t n,
dfsan_label s1_label, dfsan_label s2_label,
dfsan_label n_label, dfsan_origin s1_origin,
dfsan_origin s2_origin, dfsan_origin n_origin)
SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_strncmp(const char *s1, const char *s2,
size_t n, dfsan_label s1_label,
dfsan_label s2_label,
dfsan_label n_label,
dfsan_label *ret_label) {
if (n == 0) {
*ret_label = 0;
return 0;
}
CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strncmp, GET_CALLER_PC(), s1, s2,
n, s1_label, s2_label, n_label);
size_t bytes_read;
int r = dfsan_strncmp(s1, s2, n, &bytes_read);
*ret_label = dfsan_get_memcmp_label(s1, s2, bytes_read);
return r;
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfso_strncmp(
const char *s1, const char *s2, size_t n, dfsan_label s1_label,
dfsan_label s2_label, dfsan_label n_label, dfsan_label *ret_label,
dfsan_origin s1_origin, dfsan_origin s2_origin, dfsan_origin n_origin,
dfsan_origin *ret_origin) {
if (n == 0) {
*ret_label = 0;
return 0;
}
CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_origin_strncmp, GET_CALLER_PC(),
s1, s2, n, s1_label, s2_label, n_label, s1_origin,
s2_origin, n_origin);
size_t bytes_read;
int r = dfsan_strncmp(s1, s2, n, &bytes_read);
dfsan_get_memcmp_origin(s1, s2, bytes_read, ret_label, ret_origin);
return r;
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_strncasecmp(
const char *s1, const char *s2, size_t n, dfsan_label s1_label,
dfsan_label s2_label, dfsan_label n_label, dfsan_label *ret_label) {
if (n == 0) {
*ret_label = 0;
return 0;
}
size_t bytes_read;
int r = dfsan_strncasecmp(s1, s2, n, &bytes_read);
*ret_label = dfsan_get_memcmp_label(s1, s2, bytes_read);
return r;
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfso_strncasecmp(
const char *s1, const char *s2, size_t n, dfsan_label s1_label,
dfsan_label s2_label, dfsan_label n_label, dfsan_label *ret_label,
dfsan_origin s1_origin, dfsan_origin s2_origin, dfsan_origin n_origin,
dfsan_origin *ret_origin) {
if (n == 0) {
*ret_label = 0;
return 0;
}
size_t bytes_read;
int r = dfsan_strncasecmp(s1, s2, n, &bytes_read);
dfsan_get_memcmp_origin(s1, s2, bytes_read, ret_label, ret_origin);
return r;
}
SANITIZER_INTERFACE_ATTRIBUTE size_t
__dfsw_strlen(const char *s, dfsan_label s_label, dfsan_label *ret_label) {
size_t ret = strlen(s);
if (flags().strict_data_dependencies) {
*ret_label = 0;
} else {
*ret_label = dfsan_read_label(s, ret + 1);
}
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE size_t __dfso_strlen(const char *s,
dfsan_label s_label,
dfsan_label *ret_label,
dfsan_origin s_origin,
dfsan_origin *ret_origin) {
size_t ret = __dfsw_strlen(s, s_label, ret_label);
if (!flags().strict_data_dependencies)
*ret_origin = dfsan_read_origin_of_first_taint(s, ret + 1);
return ret;
}
static void *dfsan_memmove(void *dest, const void *src, size_t n) {
dfsan_label *sdest = shadow_for(dest);
const dfsan_label *ssrc = shadow_for(src);
internal_memmove((void *)sdest, (const void *)ssrc, n * sizeof(dfsan_label));
return internal_memmove(dest, src, n);
}
static void *dfsan_memmove_with_origin(void *dest, const void *src, size_t n) {
dfsan_mem_origin_transfer(dest, src, n);
return dfsan_memmove(dest, src, n);
}
static void *dfsan_memcpy(void *dest, const void *src, size_t n) {
dfsan_label *sdest = shadow_for(dest);
const dfsan_label *ssrc = shadow_for(src);
internal_memcpy((void *)sdest, (const void *)ssrc, n * sizeof(dfsan_label));
return internal_memcpy(dest, src, n);
}
static void *dfsan_memcpy_with_origin(void *dest, const void *src, size_t n) {
dfsan_mem_origin_transfer(dest, src, n);
return dfsan_memcpy(dest, src, n);
}
static void dfsan_memset(void *s, int c, dfsan_label c_label, size_t n) {
internal_memset(s, c, n);
dfsan_set_label(c_label, s, n);
}
static void dfsan_memset_with_origin(void *s, int c, dfsan_label c_label,
dfsan_origin c_origin, size_t n) {
internal_memset(s, c, n);
dfsan_set_label_origin(c_label, c_origin, s, n);
}
SANITIZER_INTERFACE_ATTRIBUTE
void *__dfsw_memcpy(void *dest, const void *src, size_t n,
dfsan_label dest_label, dfsan_label src_label,
dfsan_label n_label, dfsan_label *ret_label) {
*ret_label = dest_label;
return dfsan_memcpy(dest, src, n);
}
SANITIZER_INTERFACE_ATTRIBUTE
void *__dfso_memcpy(void *dest, const void *src, size_t n,
dfsan_label dest_label, dfsan_label src_label,
dfsan_label n_label, dfsan_label *ret_label,
dfsan_origin dest_origin, dfsan_origin src_origin,
dfsan_origin n_origin, dfsan_origin *ret_origin) {
*ret_label = dest_label;
*ret_origin = dest_origin;
return dfsan_memcpy_with_origin(dest, src, n);
}
SANITIZER_INTERFACE_ATTRIBUTE
void *__dfsw_memmove(void *dest, const void *src, size_t n,
dfsan_label dest_label, dfsan_label src_label,
dfsan_label n_label, dfsan_label *ret_label) {
*ret_label = dest_label;
return dfsan_memmove(dest, src, n);
}
SANITIZER_INTERFACE_ATTRIBUTE
void *__dfso_memmove(void *dest, const void *src, size_t n,
dfsan_label dest_label, dfsan_label src_label,
dfsan_label n_label, dfsan_label *ret_label,
dfsan_origin dest_origin, dfsan_origin src_origin,
dfsan_origin n_origin, dfsan_origin *ret_origin) {
*ret_label = dest_label;
*ret_origin = dest_origin;
return dfsan_memmove_with_origin(dest, src, n);
}
SANITIZER_INTERFACE_ATTRIBUTE
void *__dfsw_memset(void *s, int c, size_t n,
dfsan_label s_label, dfsan_label c_label,
dfsan_label n_label, dfsan_label *ret_label) {
dfsan_memset(s, c, c_label, n);
*ret_label = s_label;
return s;
}
SANITIZER_INTERFACE_ATTRIBUTE
void *__dfso_memset(void *s, int c, size_t n, dfsan_label s_label,
dfsan_label c_label, dfsan_label n_label,
dfsan_label *ret_label, dfsan_origin s_origin,
dfsan_origin c_origin, dfsan_origin n_origin,
dfsan_origin *ret_origin) {
dfsan_memset_with_origin(s, c, c_label, c_origin, n);
*ret_label = s_label;
*ret_origin = s_origin;
return s;
}
SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strcat(char *dest, const char *src,
dfsan_label dest_label,
dfsan_label src_label,
dfsan_label *ret_label) {
size_t dest_len = strlen(dest);
char *ret = strcat(dest, src);
dfsan_label *sdest = shadow_for(dest + dest_len);
const dfsan_label *ssrc = shadow_for(src);
internal_memcpy((void *)sdest, (const void *)ssrc,
strlen(src) * sizeof(dfsan_label));
*ret_label = dest_label;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE char *__dfso_strcat(
char *dest, const char *src, dfsan_label dest_label, dfsan_label src_label,
dfsan_label *ret_label, dfsan_origin dest_origin, dfsan_origin src_origin,
dfsan_origin *ret_origin) {
size_t dest_len = strlen(dest);
char *ret = strcat(dest, src);
dfsan_label *sdest = shadow_for(dest + dest_len);
const dfsan_label *ssrc = shadow_for(src);
size_t src_len = strlen(src);
dfsan_mem_origin_transfer(dest + dest_len, src, src_len);
internal_memcpy((void *)sdest, (const void *)ssrc,
src_len * sizeof(dfsan_label));
*ret_label = dest_label;
*ret_origin = dest_origin;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE char *
__dfsw_strdup(const char *s, dfsan_label s_label, dfsan_label *ret_label) {
size_t len = strlen(s);
void *p = malloc(len+1);
dfsan_memcpy(p, s, len+1);
*ret_label = 0;
return static_cast<char *>(p);
}
SANITIZER_INTERFACE_ATTRIBUTE char *__dfso_strdup(const char *s,
dfsan_label s_label,
dfsan_label *ret_label,
dfsan_origin s_origin,
dfsan_origin *ret_origin) {
size_t len = strlen(s);
void *p = malloc(len + 1);
dfsan_memcpy_with_origin(p, s, len + 1);
*ret_label = 0;
return static_cast<char *>(p);
}
SANITIZER_INTERFACE_ATTRIBUTE char *
__dfsw_strncpy(char *s1, const char *s2, size_t n, dfsan_label s1_label,
dfsan_label s2_label, dfsan_label n_label,
dfsan_label *ret_label) {
size_t len = strlen(s2);
if (len < n) {
dfsan_memcpy(s1, s2, len+1);
dfsan_memset(s1+len+1, 0, 0, n-len-1);
} else {
dfsan_memcpy(s1, s2, n);
}
*ret_label = s1_label;
return s1;
}
SANITIZER_INTERFACE_ATTRIBUTE char *__dfso_strncpy(
char *s1, const char *s2, size_t n, dfsan_label s1_label,
dfsan_label s2_label, dfsan_label n_label, dfsan_label *ret_label,
dfsan_origin s1_origin, dfsan_origin s2_origin, dfsan_origin n_origin,
dfsan_origin *ret_origin) {
size_t len = strlen(s2);
if (len < n) {
dfsan_memcpy_with_origin(s1, s2, len + 1);
dfsan_memset_with_origin(s1 + len + 1, 0, 0, 0, n - len - 1);
} else {
dfsan_memcpy_with_origin(s1, s2, n);
}
*ret_label = s1_label;
*ret_origin = s1_origin;
return s1;
}
SANITIZER_INTERFACE_ATTRIBUTE ssize_t
__dfsw_pread(int fd, void *buf, size_t count, off_t offset,
dfsan_label fd_label, dfsan_label buf_label,
dfsan_label count_label, dfsan_label offset_label,
dfsan_label *ret_label) {
ssize_t ret = pread(fd, buf, count, offset);
if (ret > 0)
dfsan_set_label(0, buf, ret);
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE ssize_t __dfso_pread(
int fd, void *buf, size_t count, off_t offset, dfsan_label fd_label,
dfsan_label buf_label, dfsan_label count_label, dfsan_label offset_label,
dfsan_label *ret_label, dfsan_origin fd_origin, dfsan_origin buf_origin,
dfsan_origin count_origin, dfsan_label offset_origin,
dfsan_origin *ret_origin) {
return __dfsw_pread(fd, buf, count, offset, fd_label, buf_label, count_label,
offset_label, ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE ssize_t
__dfsw_read(int fd, void *buf, size_t count,
dfsan_label fd_label, dfsan_label buf_label,
dfsan_label count_label,
dfsan_label *ret_label) {
ssize_t ret = read(fd, buf, count);
if (ret > 0)
dfsan_set_label(0, buf, ret);
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE ssize_t __dfso_read(
int fd, void *buf, size_t count, dfsan_label fd_label,
dfsan_label buf_label, dfsan_label count_label, dfsan_label *ret_label,
dfsan_origin fd_origin, dfsan_origin buf_origin, dfsan_origin count_origin,
dfsan_origin *ret_origin) {
return __dfsw_read(fd, buf, count, fd_label, buf_label, count_label,
ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_clock_gettime(clockid_t clk_id,
struct timespec *tp,
dfsan_label clk_id_label,
dfsan_label tp_label,
dfsan_label *ret_label) {
int ret = clock_gettime(clk_id, tp);
if (ret == 0)
dfsan_set_label(0, tp, sizeof(struct timespec));
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfso_clock_gettime(
clockid_t clk_id, struct timespec *tp, dfsan_label clk_id_label,
dfsan_label tp_label, dfsan_label *ret_label, dfsan_origin clk_id_origin,
dfsan_origin tp_origin, dfsan_origin *ret_origin) {
return __dfsw_clock_gettime(clk_id, tp, clk_id_label, tp_label, ret_label);
}
static void dfsan_set_zero_label(const void *ptr, uptr size) {
dfsan_set_label(0, const_cast<void *>(ptr), size);
}
// dlopen() ultimately calls mmap() down inside the loader, which generally
// doesn't participate in dynamic symbol resolution. Therefore we won't
// intercept its calls to mmap, and we have to hook it here.
SANITIZER_INTERFACE_ATTRIBUTE void *
__dfsw_dlopen(const char *filename, int flag, dfsan_label filename_label,
dfsan_label flag_label, dfsan_label *ret_label) {
void *handle = dlopen(filename, flag);
link_map *map = GET_LINK_MAP_BY_DLOPEN_HANDLE(handle);
if (map)
ForEachMappedRegion(map, dfsan_set_zero_label);
*ret_label = 0;
return handle;
}
SANITIZER_INTERFACE_ATTRIBUTE void *__dfso_dlopen(
const char *filename, int flag, dfsan_label filename_label,
dfsan_label flag_label, dfsan_label *ret_label,
dfsan_origin filename_origin, dfsan_origin flag_origin,
dfsan_origin *ret_origin) {
return __dfsw_dlopen(filename, flag, filename_label, flag_label, ret_label);
}
static void *DFsanThreadStartFunc(void *arg) {
DFsanThread *t = (DFsanThread *)arg;
SetCurrentThread(t);
t->Init();
SetSigProcMask(&t->starting_sigset_, nullptr);
return t->ThreadStart();
}
static int dfsan_pthread_create(pthread_t *thread, const pthread_attr_t *attr,
void *start_routine_trampoline,
void *start_routine, void *arg,
dfsan_label *ret_label,
bool track_origins = false) {
pthread_attr_t myattr;
if (!attr) {
pthread_attr_init(&myattr);
attr = &myattr;
}
// Ensure that the thread stack is large enough to hold all TLS data.
AdjustStackSize((void *)(const_cast<pthread_attr_t *>(attr)));
DFsanThread *t =
DFsanThread::Create(start_routine_trampoline,
(thread_callback_t)start_routine, arg, track_origins);
ScopedBlockSignals block(&t->starting_sigset_);
int res = pthread_create(thread, attr, DFsanThreadStartFunc, t);
if (attr == &myattr)
pthread_attr_destroy(&myattr);
*ret_label = 0;
return res;
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_pthread_create(
pthread_t *thread, const pthread_attr_t *attr,
void *(*start_routine_trampoline)(void *, void *, dfsan_label,
dfsan_label *),
void *start_routine, void *arg, dfsan_label thread_label,
dfsan_label attr_label, dfsan_label start_routine_label,
dfsan_label arg_label, dfsan_label *ret_label) {
return dfsan_pthread_create(thread, attr, (void *)start_routine_trampoline,
start_routine, arg, ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfso_pthread_create(
pthread_t *thread, const pthread_attr_t *attr,
void *(*start_routine_trampoline)(void *, void *, dfsan_label,
dfsan_label *, dfsan_origin,
dfsan_origin *),
void *start_routine, void *arg, dfsan_label thread_label,
dfsan_label attr_label, dfsan_label start_routine_label,
dfsan_label arg_label, dfsan_label *ret_label, dfsan_origin thread_origin,
dfsan_origin attr_origin, dfsan_origin start_routine_origin,
dfsan_origin arg_origin, dfsan_origin *ret_origin) {
return dfsan_pthread_create(thread, attr, (void *)start_routine_trampoline,
start_routine, arg, ret_label, true);
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_pthread_join(pthread_t thread,
void **retval,
dfsan_label thread_label,
dfsan_label retval_label,
dfsan_label *ret_label) {
int ret = pthread_join(thread, retval);
if (ret == 0 && retval)
dfsan_set_label(0, retval, sizeof(*retval));
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfso_pthread_join(
pthread_t thread, void **retval, dfsan_label thread_label,
dfsan_label retval_label, dfsan_label *ret_label,
dfsan_origin thread_origin, dfsan_origin retval_origin,
dfsan_origin *ret_origin) {
return __dfsw_pthread_join(thread, retval, thread_label, retval_label,
ret_label);
}
struct dl_iterate_phdr_info {
int (*callback_trampoline)(void *callback, struct dl_phdr_info *info,
size_t size, void *data, dfsan_label info_label,
dfsan_label size_label, dfsan_label data_label,
dfsan_label *ret_label);
void *callback;
void *data;
};
struct dl_iterate_phdr_origin_info {
int (*callback_trampoline)(void *callback, struct dl_phdr_info *info,
size_t size, void *data, dfsan_label info_label,
dfsan_label size_label, dfsan_label data_label,
dfsan_label *ret_label, dfsan_origin info_origin,
dfsan_origin size_origin, dfsan_origin data_origin,
dfsan_origin *ret_origin);
void *callback;
void *data;
};
int dl_iterate_phdr_cb(struct dl_phdr_info *info, size_t size, void *data) {
dl_iterate_phdr_info *dipi = (dl_iterate_phdr_info *)data;
dfsan_set_label(0, *info);
dfsan_set_label(0, const_cast<char *>(info->dlpi_name),
strlen(info->dlpi_name) + 1);
dfsan_set_label(
0, const_cast<char *>(reinterpret_cast<const char *>(info->dlpi_phdr)),
sizeof(*info->dlpi_phdr) * info->dlpi_phnum);
dfsan_label ret_label;
return dipi->callback_trampoline(dipi->callback, info, size, dipi->data, 0, 0,
0, &ret_label);
}
int dl_iterate_phdr_origin_cb(struct dl_phdr_info *info, size_t size,
void *data) {
dl_iterate_phdr_origin_info *dipi = (dl_iterate_phdr_origin_info *)data;
dfsan_set_label(0, *info);
dfsan_set_label(0, const_cast<char *>(info->dlpi_name),
strlen(info->dlpi_name) + 1);
dfsan_set_label(
0, const_cast<char *>(reinterpret_cast<const char *>(info->dlpi_phdr)),
sizeof(*info->dlpi_phdr) * info->dlpi_phnum);
dfsan_label ret_label;
dfsan_origin ret_origin;
return dipi->callback_trampoline(dipi->callback, info, size, dipi->data, 0, 0,
0, &ret_label, 0, 0, 0, &ret_origin);
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_dl_iterate_phdr(
int (*callback_trampoline)(void *callback, struct dl_phdr_info *info,
size_t size, void *data, dfsan_label info_label,
dfsan_label size_label, dfsan_label data_label,
dfsan_label *ret_label),
void *callback, void *data, dfsan_label callback_label,
dfsan_label data_label, dfsan_label *ret_label) {
dl_iterate_phdr_info dipi = { callback_trampoline, callback, data };
*ret_label = 0;
return dl_iterate_phdr(dl_iterate_phdr_cb, &dipi);
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfso_dl_iterate_phdr(
int (*callback_trampoline)(void *callback, struct dl_phdr_info *info,
size_t size, void *data, dfsan_label info_label,
dfsan_label size_label, dfsan_label data_label,
dfsan_label *ret_label, dfsan_origin info_origin,
dfsan_origin size_origin,
dfsan_origin data_origin,
dfsan_origin *ret_origin),
void *callback, void *data, dfsan_label callback_label,
dfsan_label data_label, dfsan_label *ret_label,
dfsan_origin callback_origin, dfsan_origin data_origin,
dfsan_origin *ret_origin) {
dl_iterate_phdr_origin_info dipi = {callback_trampoline, callback, data};
*ret_label = 0;
return dl_iterate_phdr(dl_iterate_phdr_origin_cb, &dipi);
}
// This function is only available for glibc 2.27 or newer. Mark it weak so
// linking succeeds with older glibcs.
SANITIZER_WEAK_ATTRIBUTE void _dl_get_tls_static_info(size_t *sizep,
size_t *alignp);
SANITIZER_INTERFACE_ATTRIBUTE void __dfsw__dl_get_tls_static_info(
size_t *sizep, size_t *alignp, dfsan_label sizep_label,
dfsan_label alignp_label) {
assert(_dl_get_tls_static_info);
_dl_get_tls_static_info(sizep, alignp);
dfsan_set_label(0, sizep, sizeof(*sizep));
dfsan_set_label(0, alignp, sizeof(*alignp));
}
SANITIZER_INTERFACE_ATTRIBUTE void __dfso__dl_get_tls_static_info(
size_t *sizep, size_t *alignp, dfsan_label sizep_label,
dfsan_label alignp_label, dfsan_origin sizep_origin,
dfsan_origin alignp_origin) {
__dfsw__dl_get_tls_static_info(sizep, alignp, sizep_label, alignp_label);
}
SANITIZER_INTERFACE_ATTRIBUTE
char *__dfsw_ctime_r(const time_t *timep, char *buf, dfsan_label timep_label,
dfsan_label buf_label, dfsan_label *ret_label) {
char *ret = ctime_r(timep, buf);
if (ret) {
dfsan_set_label(dfsan_read_label(timep, sizeof(time_t)), buf,
strlen(buf) + 1);
*ret_label = buf_label;
} else {
*ret_label = 0;
}
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
char *__dfso_ctime_r(const time_t *timep, char *buf, dfsan_label timep_label,
dfsan_label buf_label, dfsan_label *ret_label,
dfsan_origin timep_origin, dfsan_origin buf_origin,
dfsan_origin *ret_origin) {
char *ret = ctime_r(timep, buf);
if (ret) {
dfsan_set_label_origin(
dfsan_read_label(timep, sizeof(time_t)),
dfsan_read_origin_of_first_taint(timep, sizeof(time_t)), buf,
strlen(buf) + 1);
*ret_label = buf_label;
*ret_origin = buf_origin;
} else {
*ret_label = 0;
}
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
char *__dfsw_fgets(char *s, int size, FILE *stream, dfsan_label s_label,
dfsan_label size_label, dfsan_label stream_label,
dfsan_label *ret_label) {
char *ret = fgets(s, size, stream);
if (ret) {
dfsan_set_label(0, ret, strlen(ret) + 1);
*ret_label = s_label;
} else {
*ret_label = 0;
}
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
char *__dfso_fgets(char *s, int size, FILE *stream, dfsan_label s_label,
dfsan_label size_label, dfsan_label stream_label,
dfsan_label *ret_label, dfsan_origin s_origin,
dfsan_origin size_origin, dfsan_origin stream_origin,
dfsan_origin *ret_origin) {
char *ret = __dfsw_fgets(s, size, stream, s_label, size_label, stream_label,
ret_label);
if (ret)
*ret_origin = s_origin;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
char *__dfsw_getcwd(char *buf, size_t size, dfsan_label buf_label,
dfsan_label size_label, dfsan_label *ret_label) {
char *ret = getcwd(buf, size);
if (ret) {
dfsan_set_label(0, ret, strlen(ret) + 1);
*ret_label = buf_label;
} else {
*ret_label = 0;
}
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
char *__dfso_getcwd(char *buf, size_t size, dfsan_label buf_label,
dfsan_label size_label, dfsan_label *ret_label,
dfsan_origin buf_origin, dfsan_origin size_origin,
dfsan_origin *ret_origin) {
char *ret = __dfsw_getcwd(buf, size, buf_label, size_label, ret_label);
if (ret)
*ret_origin = buf_origin;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
char *__dfsw_get_current_dir_name(dfsan_label *ret_label) {
char *ret = get_current_dir_name();
if (ret)
dfsan_set_label(0, ret, strlen(ret) + 1);
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
char *__dfso_get_current_dir_name(dfsan_label *ret_label,
dfsan_origin *ret_origin) {
return __dfsw_get_current_dir_name(ret_label);
}
// This function is only available for glibc 2.25 or newer. Mark it weak so
// linking succeeds with older glibcs.
SANITIZER_WEAK_ATTRIBUTE int getentropy(void *buffer, size_t length);
SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_getentropy(void *buffer, size_t length,
dfsan_label buffer_label,
dfsan_label length_label,
dfsan_label *ret_label) {
int ret = getentropy(buffer, length);
if (ret == 0) {
dfsan_set_label(0, buffer, length);
}
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfso_getentropy(void *buffer, size_t length,
dfsan_label buffer_label,
dfsan_label length_label,
dfsan_label *ret_label,
dfsan_origin buffer_origin,
dfsan_origin length_origin,
dfsan_origin *ret_origin) {
return __dfsw_getentropy(buffer, length, buffer_label, length_label,
ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfsw_gethostname(char *name, size_t len, dfsan_label name_label,
dfsan_label len_label, dfsan_label *ret_label) {
int ret = gethostname(name, len);
if (ret == 0) {
dfsan_set_label(0, name, strlen(name) + 1);
}
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfso_gethostname(char *name, size_t len, dfsan_label name_label,
dfsan_label len_label, dfsan_label *ret_label,
dfsan_origin name_origin, dfsan_origin len_origin,
dfsan_label *ret_origin) {
return __dfsw_gethostname(name, len, name_label, len_label, ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfsw_getrlimit(int resource, struct rlimit *rlim,
dfsan_label resource_label, dfsan_label rlim_label,
dfsan_label *ret_label) {
int ret = getrlimit(resource, rlim);
if (ret == 0) {
dfsan_set_label(0, rlim, sizeof(struct rlimit));
}
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfso_getrlimit(int resource, struct rlimit *rlim,
dfsan_label resource_label, dfsan_label rlim_label,
dfsan_label *ret_label, dfsan_origin resource_origin,
dfsan_origin rlim_origin, dfsan_origin *ret_origin) {
return __dfsw_getrlimit(resource, rlim, resource_label, rlim_label,
ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfsw_getrusage(int who, struct rusage *usage, dfsan_label who_label,
dfsan_label usage_label, dfsan_label *ret_label) {
int ret = getrusage(who, usage);
if (ret == 0) {
dfsan_set_label(0, usage, sizeof(struct rusage));
}
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfso_getrusage(int who, struct rusage *usage, dfsan_label who_label,
dfsan_label usage_label, dfsan_label *ret_label,
dfsan_origin who_origin, dfsan_origin usage_origin,
dfsan_label *ret_origin) {
return __dfsw_getrusage(who, usage, who_label, usage_label, ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE
char *__dfsw_strcpy(char *dest, const char *src, dfsan_label dst_label,
dfsan_label src_label, dfsan_label *ret_label) {
char *ret = strcpy(dest, src);
if (ret) {
internal_memcpy(shadow_for(dest), shadow_for(src),
sizeof(dfsan_label) * (strlen(src) + 1));
}
*ret_label = dst_label;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
char *__dfso_strcpy(char *dest, const char *src, dfsan_label dst_label,
dfsan_label src_label, dfsan_label *ret_label,
dfsan_origin dst_origin, dfsan_origin src_origin,
dfsan_origin *ret_origin) {
char *ret = strcpy(dest, src);
if (ret) {
size_t str_len = strlen(src) + 1;
dfsan_mem_origin_transfer(dest, src, str_len);
internal_memcpy(shadow_for(dest), shadow_for(src),
sizeof(dfsan_label) * str_len);
}
*ret_label = dst_label;
*ret_origin = dst_origin;
return ret;
}
static long int dfsan_strtol(const char *nptr, char **endptr, int base,
char **tmp_endptr) {
assert(tmp_endptr);
long int ret = strtol(nptr, tmp_endptr, base);
if (endptr)
*endptr = *tmp_endptr;
return ret;
}
static void dfsan_strtolong_label(const char *nptr, const char *tmp_endptr,
dfsan_label base_label,
dfsan_label *ret_label) {
if (tmp_endptr > nptr) {
// If *tmp_endptr is '\0' include its label as well.
*ret_label = dfsan_union(
base_label,
dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
} else {
*ret_label = 0;
}
}
static void dfsan_strtolong_origin(const char *nptr, const char *tmp_endptr,
dfsan_label base_label,
dfsan_label *ret_label,
dfsan_origin base_origin,
dfsan_origin *ret_origin) {
if (tmp_endptr > nptr) {
// When multiple inputs are tainted, we propagate one of its origins.
// Because checking if base_label is tainted does not need additional
// computation, we prefer to propagating base_origin.
*ret_origin = base_label
? base_origin
: dfsan_read_origin_of_first_taint(
nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1));
}
}
SANITIZER_INTERFACE_ATTRIBUTE
long int __dfsw_strtol(const char *nptr, char **endptr, int base,
dfsan_label nptr_label, dfsan_label endptr_label,
dfsan_label base_label, dfsan_label *ret_label) {
char *tmp_endptr;
long int ret = dfsan_strtol(nptr, endptr, base, &tmp_endptr);
dfsan_strtolong_label(nptr, tmp_endptr, base_label, ret_label);
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
long int __dfso_strtol(const char *nptr, char **endptr, int base,
dfsan_label nptr_label, dfsan_label endptr_label,
dfsan_label base_label, dfsan_label *ret_label,
dfsan_origin nptr_origin, dfsan_origin endptr_origin,
dfsan_origin base_origin, dfsan_origin *ret_origin) {
char *tmp_endptr;
long int ret = dfsan_strtol(nptr, endptr, base, &tmp_endptr);
dfsan_strtolong_label(nptr, tmp_endptr, base_label, ret_label);
dfsan_strtolong_origin(nptr, tmp_endptr, base_label, ret_label, base_origin,
ret_origin);
return ret;
}
static double dfsan_strtod(const char *nptr, char **endptr, char **tmp_endptr) {
assert(tmp_endptr);
double ret = strtod(nptr, tmp_endptr);
if (endptr)
*endptr = *tmp_endptr;
return ret;
}
static void dfsan_strtod_label(const char *nptr, const char *tmp_endptr,
dfsan_label *ret_label) {
if (tmp_endptr > nptr) {
// If *tmp_endptr is '\0' include its label as well.
*ret_label = dfsan_read_label(
nptr,
tmp_endptr - nptr + (*tmp_endptr ? 0 : 1));
} else {
*ret_label = 0;
}
}
SANITIZER_INTERFACE_ATTRIBUTE
double __dfsw_strtod(const char *nptr, char **endptr, dfsan_label nptr_label,
dfsan_label endptr_label, dfsan_label *ret_label) {
char *tmp_endptr;
double ret = dfsan_strtod(nptr, endptr, &tmp_endptr);
dfsan_strtod_label(nptr, tmp_endptr, ret_label);
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
double __dfso_strtod(const char *nptr, char **endptr, dfsan_label nptr_label,
dfsan_label endptr_label, dfsan_label *ret_label,
dfsan_origin nptr_origin, dfsan_origin endptr_origin,
dfsan_origin *ret_origin) {
char *tmp_endptr;
double ret = dfsan_strtod(nptr, endptr, &tmp_endptr);
dfsan_strtod_label(nptr, tmp_endptr, ret_label);
if (tmp_endptr > nptr) {
// If *tmp_endptr is '\0' include its label as well.
*ret_origin = dfsan_read_origin_of_first_taint(
nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1));
} else {
*ret_origin = 0;
}
return ret;
}
static long long int dfsan_strtoll(const char *nptr, char **endptr, int base,
char **tmp_endptr) {
assert(tmp_endptr);
long long int ret = strtoll(nptr, tmp_endptr, base);
if (endptr)
*endptr = *tmp_endptr;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
long long int __dfsw_strtoll(const char *nptr, char **endptr, int base,
dfsan_label nptr_label, dfsan_label endptr_label,
dfsan_label base_label, dfsan_label *ret_label) {
char *tmp_endptr;
long long int ret = dfsan_strtoll(nptr, endptr, base, &tmp_endptr);
dfsan_strtolong_label(nptr, tmp_endptr, base_label, ret_label);
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
long long int __dfso_strtoll(const char *nptr, char **endptr, int base,
dfsan_label nptr_label, dfsan_label endptr_label,
dfsan_label base_label, dfsan_label *ret_label,
dfsan_origin nptr_origin,
dfsan_origin endptr_origin,
dfsan_origin base_origin,
dfsan_origin *ret_origin) {
char *tmp_endptr;
long long int ret = dfsan_strtoll(nptr, endptr, base, &tmp_endptr);
dfsan_strtolong_label(nptr, tmp_endptr, base_label, ret_label);
dfsan_strtolong_origin(nptr, tmp_endptr, base_label, ret_label, base_origin,
ret_origin);
return ret;
}
static unsigned long int dfsan_strtoul(const char *nptr, char **endptr,
int base, char **tmp_endptr) {
assert(tmp_endptr);
unsigned long int ret = strtoul(nptr, tmp_endptr, base);
if (endptr)
*endptr = *tmp_endptr;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
unsigned long int __dfsw_strtoul(const char *nptr, char **endptr, int base,
dfsan_label nptr_label, dfsan_label endptr_label,
dfsan_label base_label, dfsan_label *ret_label) {
char *tmp_endptr;
unsigned long int ret = dfsan_strtoul(nptr, endptr, base, &tmp_endptr);
dfsan_strtolong_label(nptr, tmp_endptr, base_label, ret_label);
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
unsigned long int __dfso_strtoul(
const char *nptr, char **endptr, int base, dfsan_label nptr_label,
dfsan_label endptr_label, dfsan_label base_label, dfsan_label *ret_label,
dfsan_origin nptr_origin, dfsan_origin endptr_origin,
dfsan_origin base_origin, dfsan_origin *ret_origin) {
char *tmp_endptr;
unsigned long int ret = dfsan_strtoul(nptr, endptr, base, &tmp_endptr);
dfsan_strtolong_label(nptr, tmp_endptr, base_label, ret_label);
dfsan_strtolong_origin(nptr, tmp_endptr, base_label, ret_label, base_origin,
ret_origin);
return ret;
}
static long long unsigned int dfsan_strtoull(const char *nptr, char **endptr,
int base, char **tmp_endptr) {
assert(tmp_endptr);
long long unsigned int ret = strtoull(nptr, tmp_endptr, base);
if (endptr)
*endptr = *tmp_endptr;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
long long unsigned int __dfsw_strtoull(const char *nptr, char **endptr,
int base, dfsan_label nptr_label,
dfsan_label endptr_label,
dfsan_label base_label,
dfsan_label *ret_label) {
char *tmp_endptr;
long long unsigned int ret = dfsan_strtoull(nptr, endptr, base, &tmp_endptr);
dfsan_strtolong_label(nptr, tmp_endptr, base_label, ret_label);
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
long long unsigned int __dfso_strtoull(
const char *nptr, char **endptr, int base, dfsan_label nptr_label,
dfsan_label endptr_label, dfsan_label base_label, dfsan_label *ret_label,
dfsan_origin nptr_origin, dfsan_origin endptr_origin,
dfsan_origin base_origin, dfsan_origin *ret_origin) {
char *tmp_endptr;
long long unsigned int ret = dfsan_strtoull(nptr, endptr, base, &tmp_endptr);
dfsan_strtolong_label(nptr, tmp_endptr, base_label, ret_label);
dfsan_strtolong_origin(nptr, tmp_endptr, base_label, ret_label, base_origin,
ret_origin);
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
time_t __dfsw_time(time_t *t, dfsan_label t_label, dfsan_label *ret_label) {
time_t ret = time(t);
if (ret != (time_t) -1 && t) {
dfsan_set_label(0, t, sizeof(time_t));
}
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
time_t __dfso_time(time_t *t, dfsan_label t_label, dfsan_label *ret_label,
dfsan_origin t_origin, dfsan_origin *ret_origin) {
return __dfsw_time(t, t_label, ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfsw_inet_pton(int af, const char *src, void *dst, dfsan_label af_label,
dfsan_label src_label, dfsan_label dst_label,
dfsan_label *ret_label) {
int ret = inet_pton(af, src, dst);
if (ret == 1) {
dfsan_set_label(dfsan_read_label(src, strlen(src) + 1), dst,
af == AF_INET ? sizeof(struct in_addr) : sizeof(in6_addr));
}
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfso_inet_pton(int af, const char *src, void *dst, dfsan_label af_label,
dfsan_label src_label, dfsan_label dst_label,
dfsan_label *ret_label, dfsan_origin af_origin,
dfsan_origin src_origin, dfsan_origin dst_origin,
dfsan_origin *ret_origin) {
int ret = inet_pton(af, src, dst);
if (ret == 1) {
int src_len = strlen(src) + 1;
dfsan_set_label_origin(
dfsan_read_label(src, src_len),
dfsan_read_origin_of_first_taint(src, src_len), dst,
af == AF_INET ? sizeof(struct in_addr) : sizeof(in6_addr));
}
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
struct tm *__dfsw_localtime_r(const time_t *timep, struct tm *result,
dfsan_label timep_label, dfsan_label result_label,
dfsan_label *ret_label) {
struct tm *ret = localtime_r(timep, result);
if (ret) {
dfsan_set_label(dfsan_read_label(timep, sizeof(time_t)), result,
sizeof(struct tm));
*ret_label = result_label;
} else {
*ret_label = 0;
}
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
struct tm *__dfso_localtime_r(const time_t *timep, struct tm *result,
dfsan_label timep_label, dfsan_label result_label,
dfsan_label *ret_label, dfsan_origin timep_origin,
dfsan_origin result_origin,
dfsan_origin *ret_origin) {
struct tm *ret = localtime_r(timep, result);
if (ret) {
dfsan_set_label_origin(
dfsan_read_label(timep, sizeof(time_t)),
dfsan_read_origin_of_first_taint(timep, sizeof(time_t)), result,
sizeof(struct tm));
*ret_label = result_label;
*ret_origin = result_origin;
} else {
*ret_label = 0;
}
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfsw_getpwuid_r(id_t uid, struct passwd *pwd,
char *buf, size_t buflen, struct passwd **result,
dfsan_label uid_label, dfsan_label pwd_label,
dfsan_label buf_label, dfsan_label buflen_label,
dfsan_label result_label, dfsan_label *ret_label) {
// Store the data in pwd, the strings referenced from pwd in buf, and the
// address of pwd in *result. On failure, NULL is stored in *result.
int ret = getpwuid_r(uid, pwd, buf, buflen, result);
if (ret == 0) {
dfsan_set_label(0, pwd, sizeof(struct passwd));
dfsan_set_label(0, buf, strlen(buf) + 1);
}
*ret_label = 0;
dfsan_set_label(0, result, sizeof(struct passwd*));
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfso_getpwuid_r(id_t uid, struct passwd *pwd, char *buf, size_t buflen,
struct passwd **result, dfsan_label uid_label,
dfsan_label pwd_label, dfsan_label buf_label,
dfsan_label buflen_label, dfsan_label result_label,
dfsan_label *ret_label, dfsan_origin uid_origin,
dfsan_origin pwd_origin, dfsan_origin buf_origin,
dfsan_origin buflen_origin, dfsan_origin result_origin,
dfsan_origin *ret_origin) {
return __dfsw_getpwuid_r(uid, pwd, buf, buflen, result, uid_label, pwd_label,
buf_label, buflen_label, result_label, ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfsw_epoll_wait(int epfd, struct epoll_event *events, int maxevents,
int timeout, dfsan_label epfd_label,
dfsan_label events_label, dfsan_label maxevents_label,
dfsan_label timeout_label, dfsan_label *ret_label) {
int ret = epoll_wait(epfd, events, maxevents, timeout);
if (ret > 0)
dfsan_set_label(0, events, ret * sizeof(*events));
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfso_epoll_wait(int epfd, struct epoll_event *events, int maxevents,
int timeout, dfsan_label epfd_label,
dfsan_label events_label, dfsan_label maxevents_label,
dfsan_label timeout_label, dfsan_label *ret_label,
dfsan_origin epfd_origin, dfsan_origin events_origin,
dfsan_origin maxevents_origin,
dfsan_origin timeout_origin, dfsan_origin *ret_origin) {
return __dfsw_epoll_wait(epfd, events, maxevents, timeout, epfd_label,
events_label, maxevents_label, timeout_label,
ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfsw_poll(struct pollfd *fds, nfds_t nfds, int timeout,
dfsan_label dfs_label, dfsan_label nfds_label,
dfsan_label timeout_label, dfsan_label *ret_label) {
int ret = poll(fds, nfds, timeout);
if (ret >= 0) {
for (; nfds > 0; --nfds) {
dfsan_set_label(0, &fds[nfds - 1].revents, sizeof(fds[nfds - 1].revents));
}
}
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfso_poll(struct pollfd *fds, nfds_t nfds, int timeout,
dfsan_label dfs_label, dfsan_label nfds_label,
dfsan_label timeout_label, dfsan_label *ret_label,
dfsan_origin dfs_origin, dfsan_origin nfds_origin,
dfsan_origin timeout_origin, dfsan_origin *ret_origin) {
return __dfsw_poll(fds, nfds, timeout, dfs_label, nfds_label, timeout_label,
ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfsw_select(int nfds, fd_set *readfds, fd_set *writefds,
fd_set *exceptfds, struct timeval *timeout,
dfsan_label nfds_label, dfsan_label readfds_label,
dfsan_label writefds_label, dfsan_label exceptfds_label,
dfsan_label timeout_label, dfsan_label *ret_label) {
int ret = select(nfds, readfds, writefds, exceptfds, timeout);
// Clear everything (also on error) since their content is either set or
// undefined.
if (readfds) {
dfsan_set_label(0, readfds, sizeof(fd_set));
}
if (writefds) {
dfsan_set_label(0, writefds, sizeof(fd_set));
}
if (exceptfds) {
dfsan_set_label(0, exceptfds, sizeof(fd_set));
}
dfsan_set_label(0, timeout, sizeof(struct timeval));
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfso_select(int nfds, fd_set *readfds, fd_set *writefds,
fd_set *exceptfds, struct timeval *timeout,
dfsan_label nfds_label, dfsan_label readfds_label,
dfsan_label writefds_label, dfsan_label exceptfds_label,
dfsan_label timeout_label, dfsan_label *ret_label,
dfsan_origin nfds_origin, dfsan_origin readfds_origin,
dfsan_origin writefds_origin, dfsan_origin exceptfds_origin,
dfsan_origin timeout_origin, dfsan_origin *ret_origin) {
return __dfsw_select(nfds, readfds, writefds, exceptfds, timeout, nfds_label,
readfds_label, writefds_label, exceptfds_label,
timeout_label, ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfsw_sched_getaffinity(pid_t pid, size_t cpusetsize, cpu_set_t *mask,
dfsan_label pid_label,
dfsan_label cpusetsize_label,
dfsan_label mask_label, dfsan_label *ret_label) {
int ret = sched_getaffinity(pid, cpusetsize, mask);
if (ret == 0) {
dfsan_set_label(0, mask, cpusetsize);
}
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfso_sched_getaffinity(pid_t pid, size_t cpusetsize, cpu_set_t *mask,
dfsan_label pid_label,
dfsan_label cpusetsize_label,
dfsan_label mask_label, dfsan_label *ret_label,
dfsan_origin pid_origin,
dfsan_origin cpusetsize_origin,
dfsan_origin mask_origin,
dfsan_origin *ret_origin) {
return __dfsw_sched_getaffinity(pid, cpusetsize, mask, pid_label,
cpusetsize_label, mask_label, ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfsw_sigemptyset(sigset_t *set, dfsan_label set_label,
dfsan_label *ret_label) {
int ret = sigemptyset(set);
dfsan_set_label(0, set, sizeof(sigset_t));
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfso_sigemptyset(sigset_t *set, dfsan_label set_label,
dfsan_label *ret_label, dfsan_origin set_origin,
dfsan_origin *ret_origin) {
return __dfsw_sigemptyset(set, set_label, ret_label);
}
class SignalHandlerScope {
public:
SignalHandlerScope() {
if (DFsanThread *t = GetCurrentThread())
t->EnterSignalHandler();
}
~SignalHandlerScope() {
if (DFsanThread *t = GetCurrentThread())
t->LeaveSignalHandler();
}
};
// Clear DFSan runtime TLS state at the end of a scope.
//
// Implementation must be async-signal-safe and use small data size, because
// instances of this class may live on the signal handler stack.
//
// DFSan uses TLS to pass metadata of arguments and return values. When an
// instrumented function accesses the TLS, if a signal callback happens, and the
// callback calls other instrumented functions with updating the same TLS, the
// TLS is in an inconsistent state after the callback ends. This may cause
// either under-tainting or over-tainting.
//
// The current implementation simply resets TLS at restore. This prevents from
// over-tainting. Although under-tainting may still happen, a taint flow can be
// found eventually if we run a DFSan-instrumented program multiple times. The
// alternative option is saving the entire TLS. However the TLS storage takes
// 2k bytes, and signal calls could be nested. So it does not seem worth.
class ScopedClearThreadLocalState {
public:
ScopedClearThreadLocalState() {}
~ScopedClearThreadLocalState() { dfsan_clear_thread_local_state(); }
};
// SignalSpinLocker::sigactions_mu guarantees atomicity of sigaction() calls.
const int kMaxSignals = 1024;
static atomic_uintptr_t sigactions[kMaxSignals];
static void SignalHandler(int signo) {
SignalHandlerScope signal_handler_scope;
ScopedClearThreadLocalState scoped_clear_tls;
// Clear shadows for all inputs provided by system. This is why DFSan
// instrumentation generates a trampoline function to each function pointer,
// and uses the trampoline to clear shadows. However sigaction does not use
// a function pointer directly, so we have to do this manually.
dfsan_clear_arg_tls(0, sizeof(dfsan_label));
typedef void (*signal_cb)(int x);
signal_cb cb =
(signal_cb)atomic_load(&sigactions[signo], memory_order_relaxed);
cb(signo);
}
static void SignalAction(int signo, siginfo_t *si, void *uc) {
SignalHandlerScope signal_handler_scope;
ScopedClearThreadLocalState scoped_clear_tls;
// Clear shadows for all inputs provided by system. Similar to SignalHandler.
dfsan_clear_arg_tls(0, 3 * sizeof(dfsan_label));
dfsan_set_label(0, si, sizeof(*si));
dfsan_set_label(0, uc, sizeof(ucontext_t));
typedef void (*sigaction_cb)(int, siginfo_t *, void *);
sigaction_cb cb =
(sigaction_cb)atomic_load(&sigactions[signo], memory_order_relaxed);
cb(signo, si, uc);
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfsw_sigaction(int signum, const struct sigaction *act,
struct sigaction *oldact, dfsan_label signum_label,
dfsan_label act_label, dfsan_label oldact_label,
dfsan_label *ret_label) {
CHECK_LT(signum, kMaxSignals);
SignalSpinLocker lock;
uptr old_cb = atomic_load(&sigactions[signum], memory_order_relaxed);
struct sigaction new_act;
struct sigaction *pnew_act = act ? &new_act : nullptr;
if (act) {
internal_memcpy(pnew_act, act, sizeof(struct sigaction));
if (pnew_act->sa_flags & SA_SIGINFO) {
uptr cb = (uptr)(pnew_act->sa_sigaction);
if (cb != (uptr)SIG_IGN && cb != (uptr)SIG_DFL) {
atomic_store(&sigactions[signum], cb, memory_order_relaxed);
pnew_act->sa_sigaction = SignalAction;
}
} else {
uptr cb = (uptr)(pnew_act->sa_handler);
if (cb != (uptr)SIG_IGN && cb != (uptr)SIG_DFL) {
atomic_store(&sigactions[signum], cb, memory_order_relaxed);
pnew_act->sa_handler = SignalHandler;
}
}
}
int ret = sigaction(signum, pnew_act, oldact);
if (ret == 0 && oldact) {
if (oldact->sa_flags & SA_SIGINFO) {
if (oldact->sa_sigaction == SignalAction)
oldact->sa_sigaction = (decltype(oldact->sa_sigaction))old_cb;
} else {
if (oldact->sa_handler == SignalHandler)
oldact->sa_handler = (decltype(oldact->sa_handler))old_cb;
}
}
if (oldact) {
dfsan_set_label(0, oldact, sizeof(struct sigaction));
}
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfso_sigaction(int signum, const struct sigaction *act,
struct sigaction *oldact, dfsan_label signum_label,
dfsan_label act_label, dfsan_label oldact_label,
dfsan_label *ret_label, dfsan_origin signum_origin,
dfsan_origin act_origin, dfsan_origin oldact_origin,
dfsan_origin *ret_origin) {
return __dfsw_sigaction(signum, act, oldact, signum_label, act_label,
oldact_label, ret_label);
}
static sighandler_t dfsan_signal(int signum, sighandler_t handler,
dfsan_label *ret_label) {
CHECK_LT(signum, kMaxSignals);
SignalSpinLocker lock;
uptr old_cb = atomic_load(&sigactions[signum], memory_order_relaxed);
if (handler != SIG_IGN && handler != SIG_DFL) {
atomic_store(&sigactions[signum], (uptr)handler, memory_order_relaxed);
handler = &SignalHandler;
}
sighandler_t ret = signal(signum, handler);
if (ret == SignalHandler)
ret = (sighandler_t)old_cb;
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
sighandler_t __dfsw_signal(int signum,
void *(*handler_trampoline)(void *, int, dfsan_label,
dfsan_label *),
sighandler_t handler, dfsan_label signum_label,
dfsan_label handler_label, dfsan_label *ret_label) {
return dfsan_signal(signum, handler, ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE
sighandler_t __dfso_signal(
int signum,
void *(*handler_trampoline)(void *, int, dfsan_label, dfsan_label *,
dfsan_origin, dfsan_origin *),
sighandler_t handler, dfsan_label signum_label, dfsan_label handler_label,
dfsan_label *ret_label, dfsan_origin signum_origin,
dfsan_origin handler_origin, dfsan_origin *ret_origin) {
return dfsan_signal(signum, handler, ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfsw_sigaltstack(const stack_t *ss, stack_t *old_ss, dfsan_label ss_label,
dfsan_label old_ss_label, dfsan_label *ret_label) {
int ret = sigaltstack(ss, old_ss);
if (ret != -1 && old_ss)
dfsan_set_label(0, old_ss, sizeof(*old_ss));
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfso_sigaltstack(const stack_t *ss, stack_t *old_ss, dfsan_label ss_label,
dfsan_label old_ss_label, dfsan_label *ret_label,
dfsan_origin ss_origin, dfsan_origin old_ss_origin,
dfsan_origin *ret_origin) {
return __dfsw_sigaltstack(ss, old_ss, ss_label, old_ss_label, ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfsw_gettimeofday(struct timeval *tv, struct timezone *tz,
dfsan_label tv_label, dfsan_label tz_label,
dfsan_label *ret_label) {
int ret = gettimeofday(tv, tz);
if (tv) {
dfsan_set_label(0, tv, sizeof(struct timeval));
}
if (tz) {
dfsan_set_label(0, tz, sizeof(struct timezone));
}
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE
int __dfso_gettimeofday(struct timeval *tv, struct timezone *tz,
dfsan_label tv_label, dfsan_label tz_label,
dfsan_label *ret_label, dfsan_origin tv_origin,
dfsan_origin tz_origin, dfsan_origin *ret_origin) {
return __dfsw_gettimeofday(tv, tz, tv_label, tz_label, ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE void *__dfsw_memchr(void *s, int c, size_t n,
dfsan_label s_label,
dfsan_label c_label,
dfsan_label n_label,
dfsan_label *ret_label) {
void *ret = memchr(s, c, n);
if (flags().strict_data_dependencies) {
*ret_label = ret ? s_label : 0;
} else {
size_t len =
ret ? reinterpret_cast<char *>(ret) - reinterpret_cast<char *>(s) + 1
: n;
*ret_label =
dfsan_union(dfsan_read_label(s, len), dfsan_union(s_label, c_label));
}
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE void *__dfso_memchr(
void *s, int c, size_t n, dfsan_label s_label, dfsan_label c_label,
dfsan_label n_label, dfsan_label *ret_label, dfsan_origin s_origin,
dfsan_origin c_origin, dfsan_origin n_origin, dfsan_origin *ret_origin) {
void *ret = __dfsw_memchr(s, c, n, s_label, c_label, n_label, ret_label);
if (flags().strict_data_dependencies) {
if (ret)
*ret_origin = s_origin;
} else {
size_t len =
ret ? reinterpret_cast<char *>(ret) - reinterpret_cast<char *>(s) + 1
: n;
dfsan_origin o = dfsan_read_origin_of_first_taint(s, len);
*ret_origin = o ? o : (s_label ? s_origin : c_origin);
}
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strrchr(char *s, int c,
dfsan_label s_label,
dfsan_label c_label,
dfsan_label *ret_label) {
char *ret = strrchr(s, c);
if (flags().strict_data_dependencies) {
*ret_label = ret ? s_label : 0;
} else {
*ret_label =
dfsan_union(dfsan_read_label(s, strlen(s) + 1),
dfsan_union(s_label, c_label));
}
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE char *__dfso_strrchr(
char *s, int c, dfsan_label s_label, dfsan_label c_label,
dfsan_label *ret_label, dfsan_origin s_origin, dfsan_origin c_origin,
dfsan_origin *ret_origin) {
char *ret = __dfsw_strrchr(s, c, s_label, c_label, ret_label);
if (flags().strict_data_dependencies) {
if (ret)
*ret_origin = s_origin;
} else {
size_t s_len = strlen(s) + 1;
dfsan_origin o = dfsan_read_origin_of_first_taint(s, s_len);
*ret_origin = o ? o : (s_label ? s_origin : c_origin);
}
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strstr(char *haystack, char *needle,
dfsan_label haystack_label,
dfsan_label needle_label,
dfsan_label *ret_label) {
char *ret = strstr(haystack, needle);
if (flags().strict_data_dependencies) {
*ret_label = ret ? haystack_label : 0;
} else {
size_t len = ret ? ret + strlen(needle) - haystack : strlen(haystack) + 1;
*ret_label =
dfsan_union(dfsan_read_label(haystack, len),
dfsan_union(dfsan_read_label(needle, strlen(needle) + 1),
dfsan_union(haystack_label, needle_label)));
}
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE char *__dfso_strstr(char *haystack, char *needle,
dfsan_label haystack_label,
dfsan_label needle_label,
dfsan_label *ret_label,
dfsan_origin haystack_origin,
dfsan_origin needle_origin,
dfsan_origin *ret_origin) {
char *ret =
__dfsw_strstr(haystack, needle, haystack_label, needle_label, ret_label);
if (flags().strict_data_dependencies) {
if (ret)
*ret_origin = haystack_origin;
} else {
size_t needle_len = strlen(needle);
size_t len = ret ? ret + needle_len - haystack : strlen(haystack) + 1;
dfsan_origin o = dfsan_read_origin_of_first_taint(haystack, len);
if (o) {
*ret_origin = o;
} else {
o = dfsan_read_origin_of_first_taint(needle, needle_len + 1);
*ret_origin = o ? o : (haystack_label ? haystack_origin : needle_origin);
}
}
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_nanosleep(const struct timespec *req,
struct timespec *rem,
dfsan_label req_label,
dfsan_label rem_label,
dfsan_label *ret_label) {
int ret = nanosleep(req, rem);
*ret_label = 0;
if (ret == -1) {
// Interrupted by a signal, rem is filled with the remaining time.
dfsan_set_label(0, rem, sizeof(struct timespec));
}
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfso_nanosleep(
const struct timespec *req, struct timespec *rem, dfsan_label req_label,
dfsan_label rem_label, dfsan_label *ret_label, dfsan_origin req_origin,
dfsan_origin rem_origin, dfsan_origin *ret_origin) {
return __dfsw_nanosleep(req, rem, req_label, rem_label, ret_label);
}
static void clear_msghdr_labels(size_t bytes_written, struct msghdr *msg) {
dfsan_set_label(0, msg, sizeof(*msg));
dfsan_set_label(0, msg->msg_name, msg->msg_namelen);
dfsan_set_label(0, msg->msg_control, msg->msg_controllen);
for (size_t i = 0; bytes_written > 0; ++i) {
assert(i < msg->msg_iovlen);
struct iovec *iov = &msg->msg_iov[i];
size_t iov_written =
bytes_written < iov->iov_len ? bytes_written : iov->iov_len;
dfsan_set_label(0, iov->iov_base, iov_written);
bytes_written -= iov_written;
}
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_recvmmsg(
int sockfd, struct mmsghdr *msgvec, unsigned int vlen, int flags,
struct timespec *timeout, dfsan_label sockfd_label,
dfsan_label msgvec_label, dfsan_label vlen_label, dfsan_label flags_label,
dfsan_label timeout_label, dfsan_label *ret_label) {
int ret = recvmmsg(sockfd, msgvec, vlen, flags, timeout);
for (int i = 0; i < ret; ++i) {
dfsan_set_label(0, &msgvec[i].msg_len, sizeof(msgvec[i].msg_len));
clear_msghdr_labels(msgvec[i].msg_len, &msgvec[i].msg_hdr);
}
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfso_recvmmsg(
int sockfd, struct mmsghdr *msgvec, unsigned int vlen, int flags,
struct timespec *timeout, dfsan_label sockfd_label,
dfsan_label msgvec_label, dfsan_label vlen_label, dfsan_label flags_label,
dfsan_label timeout_label, dfsan_label *ret_label,
dfsan_origin sockfd_origin, dfsan_origin msgvec_origin,
dfsan_origin vlen_origin, dfsan_origin flags_origin,
dfsan_origin timeout_origin, dfsan_origin *ret_origin) {
return __dfsw_recvmmsg(sockfd, msgvec, vlen, flags, timeout, sockfd_label,
msgvec_label, vlen_label, flags_label, timeout_label,
ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE ssize_t __dfsw_recvmsg(
int sockfd, struct msghdr *msg, int flags, dfsan_label sockfd_label,
dfsan_label msg_label, dfsan_label flags_label, dfsan_label *ret_label) {
ssize_t ret = recvmsg(sockfd, msg, flags);
if (ret >= 0)
clear_msghdr_labels(ret, msg);
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE ssize_t __dfso_recvmsg(
int sockfd, struct msghdr *msg, int flags, dfsan_label sockfd_label,
dfsan_label msg_label, dfsan_label flags_label, dfsan_label *ret_label,
dfsan_origin sockfd_origin, dfsan_origin msg_origin,
dfsan_origin flags_origin, dfsan_origin *ret_origin) {
return __dfsw_recvmsg(sockfd, msg, flags, sockfd_label, msg_label,
flags_label, ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE int
__dfsw_socketpair(int domain, int type, int protocol, int sv[2],
dfsan_label domain_label, dfsan_label type_label,
dfsan_label protocol_label, dfsan_label sv_label,
dfsan_label *ret_label) {
int ret = socketpair(domain, type, protocol, sv);
*ret_label = 0;
if (ret == 0) {
dfsan_set_label(0, sv, sizeof(*sv) * 2);
}
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfso_socketpair(
int domain, int type, int protocol, int sv[2], dfsan_label domain_label,
dfsan_label type_label, dfsan_label protocol_label, dfsan_label sv_label,
dfsan_label *ret_label, dfsan_origin domain_origin,
dfsan_origin type_origin, dfsan_origin protocol_origin,
dfsan_origin sv_origin, dfsan_origin *ret_origin) {
return __dfsw_socketpair(domain, type, protocol, sv, domain_label, type_label,
protocol_label, sv_label, ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_getsockopt(
int sockfd, int level, int optname, void *optval, socklen_t *optlen,
dfsan_label sockfd_label, dfsan_label level_label,
dfsan_label optname_label, dfsan_label optval_label,
dfsan_label optlen_label, dfsan_label *ret_label) {
int ret = getsockopt(sockfd, level, optname, optval, optlen);
if (ret != -1 && optval && optlen) {
dfsan_set_label(0, optlen, sizeof(*optlen));
dfsan_set_label(0, optval, *optlen);
}
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfso_getsockopt(
int sockfd, int level, int optname, void *optval, socklen_t *optlen,
dfsan_label sockfd_label, dfsan_label level_label,
dfsan_label optname_label, dfsan_label optval_label,
dfsan_label optlen_label, dfsan_label *ret_label,
dfsan_origin sockfd_origin, dfsan_origin level_origin,
dfsan_origin optname_origin, dfsan_origin optval_origin,
dfsan_origin optlen_origin, dfsan_origin *ret_origin) {
return __dfsw_getsockopt(sockfd, level, optname, optval, optlen, sockfd_label,
level_label, optname_label, optval_label,
optlen_label, ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_getsockname(
int sockfd, struct sockaddr *addr, socklen_t *addrlen,
dfsan_label sockfd_label, dfsan_label addr_label, dfsan_label addrlen_label,
dfsan_label *ret_label) {
socklen_t origlen = addrlen ? *addrlen : 0;
int ret = getsockname(sockfd, addr, addrlen);
if (ret != -1 && addr && addrlen) {
socklen_t written_bytes = origlen < *addrlen ? origlen : *addrlen;
dfsan_set_label(0, addrlen, sizeof(*addrlen));
dfsan_set_label(0, addr, written_bytes);
}
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfso_getsockname(
int sockfd, struct sockaddr *addr, socklen_t *addrlen,
dfsan_label sockfd_label, dfsan_label addr_label, dfsan_label addrlen_label,
dfsan_label *ret_label, dfsan_origin sockfd_origin,
dfsan_origin addr_origin, dfsan_origin addrlen_origin,
dfsan_origin *ret_origin) {
return __dfsw_getsockname(sockfd, addr, addrlen, sockfd_label, addr_label,
addrlen_label, ret_label);
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_getpeername(
int sockfd, struct sockaddr *addr, socklen_t *addrlen,
dfsan_label sockfd_label, dfsan_label addr_label, dfsan_label addrlen_label,
dfsan_label *ret_label) {
socklen_t origlen = addrlen ? *addrlen : 0;
int ret = getpeername(sockfd, addr, addrlen);
if (ret != -1 && addr && addrlen) {
socklen_t written_bytes = origlen < *addrlen ? origlen : *addrlen;
dfsan_set_label(0, addrlen, sizeof(*addrlen));
dfsan_set_label(0, addr, written_bytes);
}
*ret_label = 0;
return ret;
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfso_getpeername(
int sockfd, struct sockaddr *addr, socklen_t *addrlen,
dfsan_label sockfd_label, dfsan_label addr_label, dfsan_label addrlen_label,
dfsan_label *ret_label, dfsan_origin sockfd_origin,
dfsan_origin addr_origin, dfsan_origin addrlen_origin,
dfsan_origin *ret_origin) {
return __dfsw_getpeername(sockfd, addr, addrlen, sockfd_label, addr_label,
addrlen_label, ret_label);
}
// Type of the trampoline function passed to the custom version of
// dfsan_set_write_callback.
typedef void (*write_trampoline_t)(
void *callback,
int fd, const void *buf, ssize_t count,
dfsan_label fd_label, dfsan_label buf_label, dfsan_label count_label);
typedef void (*write_origin_trampoline_t)(
void *callback, int fd, const void *buf, ssize_t count,
dfsan_label fd_label, dfsan_label buf_label, dfsan_label count_label,
dfsan_origin fd_origin, dfsan_origin buf_origin, dfsan_origin count_origin);
// Calls to dfsan_set_write_callback() set the values in this struct.
// Calls to the custom version of write() read (and invoke) them.
static struct {
write_trampoline_t write_callback_trampoline = nullptr;
void *write_callback = nullptr;
} write_callback_info;
static struct {
write_origin_trampoline_t write_callback_trampoline = nullptr;
void *write_callback = nullptr;
} write_origin_callback_info;
SANITIZER_INTERFACE_ATTRIBUTE void
__dfsw_dfsan_set_write_callback(
write_trampoline_t write_callback_trampoline,
void *write_callback,
dfsan_label write_callback_label,
dfsan_label *ret_label) {
write_callback_info.write_callback_trampoline = write_callback_trampoline;
write_callback_info.write_callback = write_callback;
}
SANITIZER_INTERFACE_ATTRIBUTE void __dfso_dfsan_set_write_callback(
write_origin_trampoline_t write_callback_trampoline, void *write_callback,
dfsan_label write_callback_label, dfsan_label *ret_label,
dfsan_origin write_callback_origin, dfsan_origin *ret_origin) {
write_origin_callback_info.write_callback_trampoline =
write_callback_trampoline;
write_origin_callback_info.write_callback = write_callback;
}
SANITIZER_INTERFACE_ATTRIBUTE int
__dfsw_write(int fd, const void *buf, size_t count,
dfsan_label fd_label, dfsan_label buf_label,
dfsan_label count_label, dfsan_label *ret_label) {
if (write_callback_info.write_callback) {
write_callback_info.write_callback_trampoline(
write_callback_info.write_callback,
fd, buf, count,
fd_label, buf_label, count_label);
}
*ret_label = 0;
return write(fd, buf, count);
}
SANITIZER_INTERFACE_ATTRIBUTE int __dfso_write(
int fd, const void *buf, size_t count, dfsan_label fd_label,
dfsan_label buf_label, dfsan_label count_label, dfsan_label *ret_label,
dfsan_origin fd_origin, dfsan_origin buf_origin, dfsan_origin count_origin,
dfsan_origin *ret_origin) {
if (write_origin_callback_info.write_callback) {
write_origin_callback_info.write_callback_trampoline(
write_origin_callback_info.write_callback, fd, buf, count, fd_label,
buf_label, count_label, fd_origin, buf_origin, count_origin);
}
*ret_label = 0;
return write(fd, buf, count);
}
} // namespace __dfsan
// Type used to extract a dfsan_label with va_arg()
typedef int dfsan_label_va;
// Formats a chunk either a constant string or a single format directive (e.g.,
// '%.3f').
struct Formatter {
Formatter(char *str_, const char *fmt_, size_t size_)
: str(str_), str_off(0), size(size_), fmt_start(fmt_), fmt_cur(fmt_),
width(-1) {}
int format() {
char *tmp_fmt = build_format_string();
int retval =
snprintf(str + str_off, str_off < size ? size - str_off : 0, tmp_fmt,
0 /* used only to avoid warnings */);
free(tmp_fmt);
return retval;
}
template <typename T> int format(T arg) {
char *tmp_fmt = build_format_string();
int retval;
if (width >= 0) {
retval = snprintf(str + str_off, str_off < size ? size - str_off : 0,
tmp_fmt, width, arg);
} else {
retval = snprintf(str + str_off, str_off < size ? size - str_off : 0,
tmp_fmt, arg);
}
free(tmp_fmt);
return retval;
}
char *build_format_string() {
size_t fmt_size = fmt_cur - fmt_start + 1;
char *new_fmt = (char *)malloc(fmt_size + 1);
assert(new_fmt);
internal_memcpy(new_fmt, fmt_start, fmt_size);
new_fmt[fmt_size] = '\0';
return new_fmt;
}
char *str_cur() { return str + str_off; }
size_t num_written_bytes(int retval) {
if (retval < 0) {
return 0;
}
size_t num_avail = str_off < size ? size - str_off : 0;
if (num_avail == 0) {
return 0;
}
size_t num_written = retval;
// A return value of {v,}snprintf of size or more means that the output was
// truncated.
if (num_written >= num_avail) {
num_written -= num_avail;
}
return num_written;
}
char *str;
size_t str_off;
size_t size;
const char *fmt_start;
const char *fmt_cur;
int width;
};
// Formats the input and propagates the input labels to the output. The output
// is stored in 'str'. 'size' bounds the number of output bytes. 'format' and
// 'ap' are the format string and the list of arguments for formatting. Returns
// the return value vsnprintf would return.
//
// The function tokenizes the format string in chunks representing either a
// constant string or a single format directive (e.g., '%.3f') and formats each
// chunk independently into the output string. This approach allows to figure
// out which bytes of the output string depends on which argument and thus to
// propagate labels more precisely.
//
// WARNING: This implementation does not support conversion specifiers with
// positional arguments.
static int format_buffer(char *str, size_t size, const char *fmt,
dfsan_label *va_labels, dfsan_label *ret_label,
dfsan_origin *va_origins, dfsan_origin *ret_origin,
va_list ap) {
Formatter formatter(str, fmt, size);
while (*formatter.fmt_cur) {
formatter.fmt_start = formatter.fmt_cur;
formatter.width = -1;
int retval = 0;
if (*formatter.fmt_cur != '%') {
// Ordinary character. Consume all the characters until a '%' or the end
// of the string.
for (; *(formatter.fmt_cur + 1) && *(formatter.fmt_cur + 1) != '%';
++formatter.fmt_cur) {}
retval = formatter.format();
dfsan_set_label(0, formatter.str_cur(),
formatter.num_written_bytes(retval));
} else {
// Conversion directive. Consume all the characters until a conversion
// specifier or the end of the string.
bool end_fmt = false;
for (; *formatter.fmt_cur && !end_fmt; ) {
switch (*++formatter.fmt_cur) {
case 'd':
case 'i':
case 'o':
case 'u':
case 'x':
case 'X':
switch (*(formatter.fmt_cur - 1)) {
case 'h':
// Also covers the 'hh' case (since the size of the arg is still
// an int).
retval = formatter.format(va_arg(ap, int));
break;
case 'l':
if (formatter.fmt_cur - formatter.fmt_start >= 2 &&
*(formatter.fmt_cur - 2) == 'l') {
retval = formatter.format(va_arg(ap, long long int));
} else {
retval = formatter.format(va_arg(ap, long int));
}
break;
case 'q':
retval = formatter.format(va_arg(ap, long long int));
break;
case 'j':
retval = formatter.format(va_arg(ap, intmax_t));
break;
case 'z':
case 't':
retval = formatter.format(va_arg(ap, size_t));
break;
default:
retval = formatter.format(va_arg(ap, int));
}
if (va_origins == nullptr)
dfsan_set_label(*va_labels++, formatter.str_cur(),
formatter.num_written_bytes(retval));
else
dfsan_set_label_origin(*va_labels++, *va_origins++,
formatter.str_cur(),
formatter.num_written_bytes(retval));
end_fmt = true;
break;
case 'a':
case 'A':
case 'e':
case 'E':
case 'f':
case 'F':
case 'g':
case 'G':
if (*(formatter.fmt_cur - 1) == 'L') {
retval = formatter.format(va_arg(ap, long double));
} else {
retval = formatter.format(va_arg(ap, double));
}
if (va_origins == nullptr)
dfsan_set_label(*va_labels++, formatter.str_cur(),
formatter.num_written_bytes(retval));
else
dfsan_set_label_origin(*va_labels++, *va_origins++,
formatter.str_cur(),
formatter.num_written_bytes(retval));
end_fmt = true;
break;
case 'c':
retval = formatter.format(va_arg(ap, int));
if (va_origins == nullptr)
dfsan_set_label(*va_labels++, formatter.str_cur(),
formatter.num_written_bytes(retval));
else
dfsan_set_label_origin(*va_labels++, *va_origins++,
formatter.str_cur(),
formatter.num_written_bytes(retval));
end_fmt = true;
break;
case 's': {
char *arg = va_arg(ap, char *);
retval = formatter.format(arg);
if (va_origins) {
va_origins++;
dfsan_mem_origin_transfer(formatter.str_cur(), arg,
formatter.num_written_bytes(retval));
}
va_labels++;
internal_memcpy(shadow_for(formatter.str_cur()), shadow_for(arg),
sizeof(dfsan_label) *
formatter.num_written_bytes(retval));
end_fmt = true;
break;
}
case 'p':
retval = formatter.format(va_arg(ap, void *));
if (va_origins == nullptr)
dfsan_set_label(*va_labels++, formatter.str_cur(),
formatter.num_written_bytes(retval));
else
dfsan_set_label_origin(*va_labels++, *va_origins++,
formatter.str_cur(),
formatter.num_written_bytes(retval));
end_fmt = true;
break;
case 'n': {
int *ptr = va_arg(ap, int *);
*ptr = (int)formatter.str_off;
va_labels++;
if (va_origins)
va_origins++;
dfsan_set_label(0, ptr, sizeof(ptr));
end_fmt = true;
break;
}
case '%':
retval = formatter.format();
dfsan_set_label(0, formatter.str_cur(),
formatter.num_written_bytes(retval));
end_fmt = true;
break;
case '*':
formatter.width = va_arg(ap, int);
va_labels++;
if (va_origins)
va_origins++;
break;
default:
break;
}
}
}
if (retval < 0) {
return retval;
}
formatter.fmt_cur++;
formatter.str_off += retval;
}
*ret_label = 0;
if (ret_origin)
*ret_origin = 0;
// Number of bytes written in total.
return formatter.str_off;
}
extern "C" {
SANITIZER_INTERFACE_ATTRIBUTE
int __dfsw_sprintf(char *str, const char *format, dfsan_label str_label,
dfsan_label format_label, dfsan_label *va_labels,
dfsan_label *ret_label, ...) {
va_list ap;
va_start(ap, ret_label);
int ret = format_buffer(str, ~0ul, format, va_labels, ret_label, nullptr,
nullptr, ap);
va_end(ap);
return ret;