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FIX #126: Extend zpaq destination buffer size by 2% in stream.c
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  This helps to protect against a buffer overrun in zpaq..

  Also, this commit adds some additional thread information
  when a block does not compress or another error occurs.
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@pete4abw
pete4abw committed Jun 29, 2023
1 parent 27e53ce commit 40fd251
Showing 1 changed file with 26 additions and 26 deletions.
52 changes: 26 additions & 26 deletions src/stream.c
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Original file line number Diff line number Diff line change
Expand Up @@ -207,22 +207,22 @@ static int zstd_compress_buf(rzip_control *control, struct compress_thread *cthr
* CTYPE_NONE */

if (zstd_ret == ZSTD_error_dstSize_tooSmall) {
print_maxverbose("Incompressible block\n");
print_maxverbose("Thread %d: Incompressible block\n", current_thread);
/* Incompressible, leave as CTYPE_NONE */
dealloc(c_buf);
return 0;
}

if (unlikely(ZSTD_isError(zstd_ret))) {
dealloc(c_buf);
print_maxverbose("zstd compress failed\n");
print_maxverbose("Thread %d: zstd compress failed\n", current_thread);
return -1;
}

/* zstd_ret is return size, not dlen */
dlen = zstd_ret;
if (unlikely(dlen >= cthread->c_len)) {
print_maxverbose("Incompressible block\n");
print_maxverbose("Thread %d: Incompressible block\n", current_thread);
/* Incompressible, leave as CTYPE_NONE */
dealloc(c_buf);
return 0;
Expand Down Expand Up @@ -266,7 +266,7 @@ static int bzip3_compress_buf(rzip_control *control, struct compress_thread *cth
c_len = bz3_encode_block(state, c_buf, cthread->s_len);

if (unlikely(c_len >= cthread->c_len)) {
print_maxverbose("Incompressible block\n");
print_maxverbose("Thread %d: Incompressible block\n", current_thread);
/* Incompressible, leave as CTYPE_NONE */
dealloc(c_buf);
return 0;
Expand Down Expand Up @@ -296,7 +296,7 @@ static int zpaq_compress_buf(rzip_control *control, struct compress_thread *cthr
compressibility = 50; /* midpoint */


c_size = round_up_page(control, cthread->s_len + 10000);
c_size = round_up_page(control, cthread->s_len * 1.02); /* increae buffer by 2% to prevent memory overrun */
c_buf = malloc(c_size);
if (!c_buf) {
print_err("Unable to allocate c_buf in zpaq_compress_buf\n");
Expand All @@ -322,7 +322,7 @@ static int zpaq_compress_buf(rzip_control *control, struct compress_thread *cthr
control->msgout, (SHOW_PROGRESS && !MAX_VERBOSE) ? true: false, current_thread);

if (unlikely(c_len >= cthread->c_len)) {
print_maxverbose("Incompressible block\n");
print_maxverbose("Thread %d: Incompressible block\n", current_thread);
/* Incompressible, leave as CTYPE_NONE */
dealloc(c_buf);
return 0;
Expand All @@ -336,7 +336,7 @@ static int zpaq_compress_buf(rzip_control *control, struct compress_thread *cthr
return 0;
}

static int bzip2_compress_buf(rzip_control *control, struct compress_thread *cthread)
static int bzip2_compress_buf(rzip_control *control, struct compress_thread *cthread, int current_thread)
{
u32 dlen = round_up_page(control, cthread->s_len);
int bzip2_ret;
Expand All @@ -361,20 +361,20 @@ static int bzip2_compress_buf(rzip_control *control, struct compress_thread *cth
* CTYPE_NONE */

if (bzip2_ret == BZ_OUTBUFF_FULL) {
print_maxverbose("Incompressible block\n");
print_maxverbose("Thread %d: Incompressible block\n", current_thread);
/* Incompressible, leave as CTYPE_NONE */
dealloc(c_buf);
return 0;
}

if (unlikely(bzip2_ret != BZ_OK)) {
dealloc(c_buf);
print_maxverbose("BZ2 compress failed\n");
print_maxverbose("Thread %d: BZ2 compress failed\n", current_thread);
return -1;
}

if (unlikely(dlen >= cthread->c_len)) {
print_maxverbose("Incompressible block\n");
print_maxverbose("Thread %d: Incompressible block\n", current_thread);
/* Incompressible, leave as CTYPE_NONE */
dealloc(c_buf);
return 0;
Expand All @@ -387,7 +387,7 @@ static int bzip2_compress_buf(rzip_control *control, struct compress_thread *cth
return 0;
}

static int gzip_compress_buf(rzip_control *control, struct compress_thread *cthread)
static int gzip_compress_buf(rzip_control *control, struct compress_thread *cthread, int current_thread)
{
unsigned long dlen = round_up_page(control, cthread->s_len);
uchar *c_buf;
Expand All @@ -406,20 +406,20 @@ static int gzip_compress_buf(rzip_control *control, struct compress_thread *cthr
* CTYPE_NONE */

if (gzip_ret == Z_BUF_ERROR) {
print_maxverbose("Incompressible block\n");
print_maxverbose("Thread %d: Incompressible block\n", current_thread);
/* Incompressible, leave as CTYPE_NONE */
dealloc(c_buf);
return 0;
}

if (unlikely(gzip_ret != Z_OK)) {
dealloc(c_buf);
print_maxverbose("compress2 failed\n");
print_maxverbose("Thread %d: compress2 failed\n", current_thread);
return -1;
}

if (unlikely((i64)dlen >= cthread->c_len)) {
print_maxverbose("Incompressible block\n");
print_maxverbose("Thread %d: Incompressible block\n", current_thread);
/* Incompressible, leave as CTYPE_NONE */
dealloc(c_buf);
return 0;
Expand Down Expand Up @@ -467,39 +467,39 @@ static int lzma_compress_buf(rzip_control *control, struct compress_thread *cthr
case SZ_ERROR_MEM:
break;
case SZ_ERROR_PARAM:
print_err("LZMA Parameter ERROR: %'d. This should not happen.\n", SZ_ERROR_PARAM);
print_err("LZMA Parameter ERROR: %d. This should not happen.\n", SZ_ERROR_PARAM);
break;
case SZ_ERROR_OUTPUT_EOF:
print_maxverbose("Harmless LZMA Output Buffer Overflow error: %'d. Incompressible block.\n", SZ_ERROR_OUTPUT_EOF);
print_maxverbose("Harmless LZMA Output Buffer Overflow error: %d. Incompressible block.\n", SZ_ERROR_OUTPUT_EOF);
break;
case SZ_ERROR_THREAD:
print_err("LZMA Multi Thread ERROR: %'d. This should not happen.\n", SZ_ERROR_THREAD);
print_err("LZMA Multi Thread ERROR: %d. This should not happen.\n", SZ_ERROR_THREAD);
break;
default:
print_err("Unidentified LZMA ERROR: %'d. This should not happen.\n", lzma_ret);
print_err("Unidentified LZMA ERROR: %d. This should not happen.\n", lzma_ret);
break;
}
/* can pass -1 if not compressible! Thanks Lasse Collin */
dealloc(c_buf);
if (lzma_ret == SZ_ERROR_MEM) {
if (lzma_level > 1) {
lzma_level--;
print_verbose("LZMA Warning: %'d. Can't allocate enough RAM for compression window, trying smaller.\n", SZ_ERROR_MEM);
print_verbose("LZMA Warning: %d. Can't allocate enough RAM for compression window, trying smaller.\n", SZ_ERROR_MEM);
goto retry;
}
/* lzma compress can be fragile on 32 bit. If it fails,
* fall back to bzip2 compression so the block doesn't
* remain uncompressed */
print_verbose("Unable to allocate enough RAM for any sized compression window, falling back to bzip2 compression.\n");
return bzip2_compress_buf(control, cthread);
return bzip2_compress_buf(control, cthread, current_thread);
} else if (lzma_ret == SZ_ERROR_OUTPUT_EOF)
return 0;
return -1;
}

if (unlikely((i64)dlen >= cthread->c_len)) {
/* Incompressible, leave as CTYPE_NONE */
print_maxverbose("Incompressible block\n");
print_maxverbose("Thread %d: Incompressible block\n", current_thread);
dealloc(c_buf);
return 0;
}
Expand All @@ -523,7 +523,7 @@ static int lzma_compress_buf(rzip_control *control, struct compress_thread *cthr
return 0;
}

static int lzo_compress_buf(rzip_control *control, struct compress_thread *cthread)
static int lzo_compress_buf(rzip_control *control, struct compress_thread *cthread, int current_thread)
{
lzo_uint in_len = cthread->s_len;
lzo_uint dlen = round_up_page(control, in_len + in_len / 16 + 64 + 3);
Expand All @@ -550,7 +550,7 @@ static int lzo_compress_buf(rzip_control *control, struct compress_thread *cthre

if (dlen >= in_len){
/* Incompressible, leave as CTYPE_NONE */
print_maxverbose("Incompressible block\n");
print_maxverbose("Thread %d: Incompressible block\n", current_thread);
dealloc(c_buf);
goto out_free;
}
Expand Down Expand Up @@ -1633,11 +1633,11 @@ static void *compthread(void *data)
if (LZMA_COMPRESS)
ret = lzma_compress_buf(control, cti, current_thread);
else if (LZO_COMPRESS)
ret = lzo_compress_buf(control, cti);
ret = lzo_compress_buf(control, cti, current_thread);
else if (BZIP2_COMPRESS)
ret = bzip2_compress_buf(control, cti);
ret = bzip2_compress_buf(control, cti, current_thread);
else if (ZLIB_COMPRESS)
ret = gzip_compress_buf(control, cti);
ret = gzip_compress_buf(control, cti, current_thread);
else if (ZPAQ_COMPRESS)
ret = zpaq_compress_buf(control, cti, current_thread);
else if (BZIP3_COMPRESS)
Expand Down

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