diff options
| -rw-r--r-- | frida_mode/src/cmplog/cmplog.c | 84 | ||||
| -rw-r--r-- | frida_mode/src/main.c | 84 |
2 files changed, 166 insertions, 2 deletions
diff --git a/frida_mode/src/cmplog/cmplog.c b/frida_mode/src/cmplog/cmplog.c index 7b11c350..3df7d13d 100644 --- a/frida_mode/src/cmplog/cmplog.c +++ b/frida_mode/src/cmplog/cmplog.c @@ -1,3 +1,8 @@ +#include <errno.h> +#include <fcntl.h> +#include <limits.h> +#include <syscall.h> + #include "frida-gum.h" #include "debug.h" @@ -5,10 +10,13 @@ #include "util.h" #define DEFAULT_MMAP_MIN_ADDR (32UL << 10) +#define FD_TMP_MAX_SIZE 65536 extern struct cmp_map *__afl_cmp_map; static GArray *cmplog_ranges = NULL; +static int fd_tmp = -1; +static ssize_t fd_tmp_size = 0; static gboolean cmplog_range(const GumRangeDetails *details, gpointer user_data) { @@ -27,6 +35,40 @@ static gint cmplog_sort(gconstpointer a, gconstpointer b) { } +static int cmplog_create_temp(void) { + + const char *tmpdir = g_get_tmp_dir(); + OKF("CMPLOG Temporary directory: %s", tmpdir); + gchar *fname = g_strdup_printf("%s/frida-cmplog-XXXXXX", tmpdir); + OKF("CMPLOG Temporary file template: %s", fname); + int fd = mkstemp(fname); + OKF("CMPLOG Temporary file: %s", fname); + + if (fd < 0) { + + FATAL("Failed to create temp file: %s, errno: %d", fname, errno); + + } + + if (unlink(fname) < 0) { + + FATAL("Failed to unlink temp file: %s (%d), errno: %d", fname, fd, errno); + + } + + if (ftruncate(fd, 0) < 0) { + + FATAL("Failed to ftruncate temp file: %s (%d), errno: %d", fname, fd, + errno); + + } + + g_free(fname); + + return fd; + +} + void cmplog_init(void) { if (__afl_cmp_map != NULL) { OKF("CMPLOG mode enabled"); } @@ -44,6 +86,13 @@ void cmplog_init(void) { } + /* + * We can't use /dev/null or /dev/zero for this since it appears that they + * don't validate the input buffer. Persumably as an optimization because they + * don't actually write any data. The file will be deleted on close. + */ + fd_tmp = cmplog_create_temp(); + } static gboolean cmplog_contains(GumAddress inner_base, GumAddress inner_limit, @@ -67,6 +116,9 @@ gboolean cmplog_is_readable(guint64 addr, size_t size) { */ if (addr < DEFAULT_MMAP_MIN_ADDR) { return false; } + /* Check our addres/length don't wrap around */ + if (SIZE_MAX - addr < size) { return false; } + GumAddress inner_base = addr; GumAddress inner_limit = inner_base + size; @@ -81,6 +133,38 @@ gboolean cmplog_is_readable(guint64 addr, size_t size) { } + /* + * Our address map can change (e.g. stack growth), use write as a fallback to + * validate our address. + */ + ssize_t written = syscall(__NR_write, fd_tmp, (void *)addr, size); + + /* + * If the write succeeds, then the buffer must be valid otherwise it would + * return EFAULT + */ + if (written > 0) { + + fd_tmp_size += written; + if (fd_tmp_size > FD_TMP_MAX_SIZE) { + + /* + * Truncate the file, we don't want our temp file to continue growing! + */ + if (ftruncate(fd_tmp, 0) < 0) { + + FATAL("Failed to truncate fd_tmp (%d), errno: %d", fd_tmp, errno); + + } + + fd_tmp_size = 0; + + } + + if ((size_t)written == size) { return true; } + + } + return false; } diff --git a/frida_mode/src/main.c b/frida_mode/src/main.c index 1ab9993f..7ff23755 100644 --- a/frida_mode/src/main.c +++ b/frida_mode/src/main.c @@ -1,4 +1,5 @@ #include <errno.h> +#include <fcntl.h> #include <unistd.h> #include <sys/types.h> @@ -27,6 +28,8 @@ #include "stats.h" #include "util.h" +#define PROC_MAX 65536 + #ifdef __APPLE__ extern mach_port_t mach_task_self(); extern GumAddress gum_darwin_find_entrypoint(mach_port_t task); @@ -78,7 +81,7 @@ static void on_main_os(int argc, char **argv, char **envp) { #endif -static void embedded_init() { +static void embedded_init(void) { static gboolean initialized = false; if (!initialized) { @@ -90,7 +93,84 @@ static void embedded_init() { } -void afl_frida_start() { +static void afl_print_cmdline(void) { + + char * buffer = g_malloc0(PROC_MAX); + gchar *fname = g_strdup_printf("/proc/%d/cmdline", getppid()); + int fd = open(fname, O_RDONLY); + + if (fd < 0) { + + FATAL("Failed to open /proc/self/cmdline, errno: (%d)", errno); + + } + + ssize_t bytes_read = read(fd, buffer, PROC_MAX - 1); + if (bytes_read < 0) { + + FATAL("Failed to read /proc/self/cmdline, errno: (%d)", errno); + + } + + int idx = 0; + + for (ssize_t i = 0; i < bytes_read; i++) { + + if (i == 0 || buffer[i - 1] == '\0') { + + OKF("AFL - COMMANDLINE: argv[%d] = %s", idx++, &buffer[i]); + + } + + } + + close(fd); + g_free(fname); + g_free(buffer); + +} + +static void afl_print_env(void) { + + char * buffer = g_malloc0(PROC_MAX); + gchar *fname = g_strdup_printf("/proc/%d/environ", getppid()); + int fd = open(fname, O_RDONLY); + + if (fd < 0) { + + FATAL("Failed to open /proc/self/cmdline, errno: (%d)", errno); + + } + + ssize_t bytes_read = read(fd, buffer, PROC_MAX - 1); + if (bytes_read < 0) { + + FATAL("Failed to read /proc/self/cmdline, errno: (%d)", errno); + + } + + int idx = 0; + + for (ssize_t i = 0; i < bytes_read; i++) { + + if (i == 0 || buffer[i - 1] == '\0') { + + OKF("AFL - ENVIRONMENT %3d: %s", idx++, &buffer[i]); + + } + + } + + close(fd); + g_free(fname); + g_free(buffer); + +} + +void afl_frida_start(void) { + + afl_print_cmdline(); + afl_print_env(); embedded_init(); stalker_init(); |