[libpng17] Use a more generous size limit for IDAT chunks.
diff --git a/ANNOUNCE b/ANNOUNCE
index b104735..2b98877 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,5 +1,5 @@
-Libpng 1.7.0beta90 - August 28, 2017
+Libpng 1.7.0beta90 - September 3, 2017
This is not intended to be a public release. It will be replaced
within a few weeks by a public version or by another test version.
@@ -1433,15 +1433,17 @@
Version 1.7.0beta88 [August 7. 2017]
Added private png_check_chunk_name() and png_check_chunk_length()
- functions.
+ functions (Fixes CVE-2017-12652).
Version 1.7.0beta89 [August 19, 2017]
Check for 0 return from png_get_rowbytes() in contrib/pngminus/*.c to stop
some Coverity issues (162705, 162706, and 162707).
-Version 1.7.0beta90 [August 28, 2017]
+Version 1.7.0beta90 [September 3, 2017]
Added PNGMINUS_UNUSED macro to contrib/pngminus/p*.c and added missing
parenthesis in contrib/pngminus/pnm2png.c (bug report by Christian Hesse).
+ Compute a larger limit on IDAT because some applications write a deflate
+ buffer for each row (Bug report by Andrew Church).
Send comments/corrections/commendations to png-mng-implement at lists.sf.net
(subscription required; visit
diff --git a/CHANGES b/CHANGES
index 04ca10f..957fe35 100644
--- a/CHANGES
+++ b/CHANGES
@@ -5734,15 +5734,17 @@
Version 1.7.0beta88 [August 7, 2017]
Initialized btoa[] in pngstest.c
Added private png_check_chunk_name() and png_check_chunk_length()
- functions.
+ functions (Fixes CVE-2017-12652).
Version 1.7.0beta89 [August 19, 2017]
Check for 0 return from png_get_rowbytes() in contrib/pngminus/*.c to stop
some Coverity issues (162705, 162706, and 162707).
-Version 1.7.0beta90 [August 28, 2017]
+Version 1.7.0beta90 [September 3, 2017]
Added PNGMINUS_UNUSED macro to contrib/pngminus/p*.c and added missing
parenthesis in contrib/pngminus/pnm2png.c (bug report by Christian Hesse).
+ Compute a larger limit on IDAT because some applications write a deflate
+ buffer for each row (Bug report by Andrew Church).
Send comments/corrections/commendations to png-mng-implement at lists.sf.net
(subscription required; visit
diff --git a/pngrutil.c b/pngrutil.c
index 0190793..c200acb 100644
--- a/pngrutil.c
+++ b/pngrutil.c
@@ -2649,31 +2649,31 @@
{
png_alloc_size_t limit = PNG_UINT_31_MAX;
- if (png_ptr->chunk_name != png_IDAT)
- {
# ifdef PNG_SET_USER_LIMITS_SUPPORTED
- if (png_ptr->user_chunk_malloc_max > 0 &&
- png_ptr->user_chunk_malloc_max < limit)
- limit = png_ptr->user_chunk_malloc_max;
+ if (png_ptr->user_chunk_malloc_max > 0 &&
+ png_ptr->user_chunk_malloc_max < limit)
+ limit = png_ptr->user_chunk_malloc_max;
# elif PNG_USER_CHUNK_MALLOC_MAX > 0
- if (PNG_USER_CHUNK_MALLOC_MAX < limit)
- limit = PNG_USER_CHUNK_MALLOC_MAX;
+ if (PNG_USER_CHUNK_MALLOC_MAX < limit)
+ limit = PNG_USER_CHUNK_MALLOC_MAX;
# endif
- }
- else
+ if (png_ptr->chunk_name == png_IDAT)
{
/* color_type 0 x 2 3 4 x 6 */
int channels[]={1,0,3,1,2,0,4};
+ png_alloc_size_t idat_limit = PNG_UINT_31_MAX;
size_t row_factor =
(png_ptr->width * channels[png_ptr->color_type] *
(png_ptr->bit_depth > 8? 2: 1)
+ 1 + (png_ptr->interlaced? 6: 0));
if (png_ptr->height > PNG_UINT_32_MAX/row_factor)
- limit=PNG_UINT_31_MAX;
+ idat_limit=PNG_UINT_31_MAX;
else
- limit = png_ptr->height * row_factor;
- limit += 6 + 5*(limit/32566+1); /* zlib+deflate overhead */
- limit=limit < PNG_UINT_31_MAX? limit : PNG_UINT_31_MAX;
+ idat_limit = png_ptr->height * row_factor;
+ row_factor = row_factor > 32566? 32566 : row_factor;
+ idat_limit += 6 + 5*(idat_limit/row_factor+1); /* zlib+deflate overhead */
+ idat_limit=idat_limit < PNG_UINT_31_MAX? idat_limit : PNG_UINT_31_MAX;
+ limit = limit < idat_limit? idat_limit : limit;
}
if (length > limit)
