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#include <assert.h>
#include <libdeflate.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <unistd.h>
static void
alloc_guarded_buffer(size_t size, uint8_t **start_ret, uint8_t **end_ret)
{
const size_t pagesize = sysconf(_SC_PAGESIZE);
const size_t nr_pages = (size + pagesize - 1) / pagesize;
uint8_t *base_addr, *start, *end;
/* Allocate buffer and guard pages. */
base_addr = mmap(NULL, (nr_pages + 2) * pagesize, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
assert(base_addr != (uint8_t *)MAP_FAILED);
start = base_addr + pagesize;
end = start + (nr_pages * pagesize);
/* Unmap the guard pages. */
munmap(base_addr, pagesize);
munmap(end, pagesize);
*start_ret = start;
*end_ret = end;
}
static void
free_guarded_buffer(uint8_t *start, uint8_t *end)
{
munmap(start, end - start);
}
/* Fuzz the DEFLATE compression and decompression round trip. */
int LLVMFuzzerTestOneInput(const uint8_t *in, size_t insize)
{
int level;
bool use_bound;
struct libdeflate_compressor *c;
struct libdeflate_decompressor *d;
size_t csize_avail;
uint8_t *ubuf_start, *ubuf_end, *ubuf;
uint8_t *cbuf_start, *cbuf_end, *cbuf;
uint8_t *dbuf_start, *dbuf_end, *dbuf;
size_t csize;
enum libdeflate_result res;
if (insize < 2)
return 0;
level = in[0] % 13;
use_bound = in[1] % 2;
in += 2;
insize -= 2;
c = libdeflate_alloc_compressor(level);
d = libdeflate_alloc_decompressor();
/* Use guard pages to make all input/output buffer overflows segfault */
alloc_guarded_buffer(insize, &ubuf_start, &ubuf_end);
ubuf = ubuf_end - insize;
memcpy(ubuf, in, insize);
csize_avail = use_bound ? libdeflate_deflate_compress_bound(c, insize) :
insize;
alloc_guarded_buffer(csize_avail, &cbuf_start, &cbuf_end);
cbuf = cbuf_end - csize_avail;
alloc_guarded_buffer(insize, &dbuf_start, &dbuf_end);
dbuf = dbuf_end - insize;
csize = libdeflate_deflate_compress(c, ubuf, insize, cbuf, csize_avail);
if (csize != 0) {
assert(csize <= csize_avail);
memmove(cbuf_end - csize, cbuf, csize);
res = libdeflate_deflate_decompress(d, cbuf_end - csize, csize,
dbuf, insize, NULL);
assert(res == LIBDEFLATE_SUCCESS);
assert(memcmp(in, dbuf, insize) == 0);
} else {
assert(!use_bound);
}
libdeflate_free_compressor(c);
libdeflate_free_decompressor(d);
free_guarded_buffer(ubuf_start, ubuf_end);
free_guarded_buffer(cbuf_start, cbuf_end);
free_guarded_buffer(dbuf_start, dbuf_end);
return 0;
}
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