Merge pull request #460 from rish9101/dev

Add post-process functionality in write_with_gap
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van Hauser 2020-07-30 09:15:42 +02:00 committed by GitHub
commit 3f9f00a798
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@ -142,18 +142,82 @@ static void write_with_gap(afl_state_t *afl, void *mem, u32 len, u32 skip_at,
s32 fd = afl->fsrv.out_fd; s32 fd = afl->fsrv.out_fd;
u32 tail_len = len - skip_at - skip_len; u32 tail_len = len - skip_at - skip_len;
/*
This memory is used to carry out the post_processing(if present) after copying
the testcase by removing the gaps. This can break though
*/
u8 mem_trimmed[len - skip_len +
1]; // 1 extra size to remove chance of overflow
ssize_t new_size = len - skip_len;
void * new_mem = mem;
u8 * new_buf = NULL;
bool post_process_skipped = true;
if (unlikely(afl->custom_mutators_count)) {
new_mem = mem_trimmed;
LIST_FOREACH(&afl->custom_mutator_list, struct custom_mutator, {
if (el->afl_custom_post_process) {
// We copy into the mem_trimmed only if we actually have custom mutators
// *with* post_processing installed
if (post_process_skipped) {
if (skip_at) { memcpy(mem_trimmed, (u8 *)mem, skip_at); }
if (tail_len) {
memcpy(mem_trimmed + skip_at, (u8 *)mem + skip_at + skip_len,
tail_len);
}
post_process_skipped = false;
}
new_size =
el->afl_custom_post_process(el->data, new_mem, new_size, &new_buf);
if (unlikely(!new_buf && (new_size <= 0))) {
FATAL("Custom_post_process failed (ret: %lu)",
(long unsigned)new_size);
}
}
new_mem = new_buf;
});
}
if (afl->fsrv.shmem_fuzz) { if (afl->fsrv.shmem_fuzz) {
if (skip_at) { memcpy(afl->fsrv.shmem_fuzz, mem, skip_at); } if (!post_process_skipped) {
if (tail_len) { // If we did post_processing, copy directly from the new_buf bufer
memcpy(afl->fsrv.shmem_fuzz + skip_at, (u8 *)mem + skip_at + skip_len, memcpy(afl->fsrv.shmem_fuzz, new_buf, new_size);
tail_len);
} }
*afl->fsrv.shmem_fuzz_len = len - skip_len; else {
memcpy(afl->fsrv.shmem_fuzz, mem, skip_at);
memcpy(afl->fsrv.shmem_fuzz, mem + skip_at + skip_len, tail_len);
}
*afl->fsrv.shmem_fuzz_len = new_size;
#ifdef _DEBUG #ifdef _DEBUG
if (afl->debug) { if (afl->debug) {
@ -197,18 +261,21 @@ static void write_with_gap(afl_state_t *afl, void *mem, u32 len, u32 skip_at,
} }
if (skip_at) { ck_write(fd, mem, skip_at, afl->fsrv.out_file); } if (!post_process_skipped) {
u8 *memu8 = mem; ck_write(fd, new_buf, new_size, afl->fsrv.out_file);
if (tail_len) {
ck_write(fd, memu8 + skip_at + skip_len, tail_len, afl->fsrv.out_file); } else {
ck_write(fd, mem, skip_at, afl->fsrv.out_file);
ck_write(fd, mem + skip_at + skip_len, tail_len, afl->fsrv.out_file);
} }
if (!afl->fsrv.out_file) { if (!afl->fsrv.out_file) {
if (ftruncate(fd, len - skip_len)) { PFATAL("ftruncate() failed"); } if (ftruncate(fd, new_size)) { PFATAL("ftruncate() failed"); }
lseek(fd, 0, SEEK_SET); lseek(fd, 0, SEEK_SET);
} else { } else {