| From 9a72a69e035ee70ff5c41541c8c61cd97990d018 Mon Sep 17 00:00:00 2001 |
| From: erouault <erouault> |
| Date: Sat, 3 Dec 2016 11:02:15 +0000 |
| Subject: [PATCH] * libtiff/tif_dirread.c: modify |
| ChopUpSingleUncompressedStrip() to instanciate compute ntrips as |
| TIFFhowmany_32(td->td_imagelength, rowsperstrip), instead of a logic based on |
| the total size of data. Which is faulty is the total size of data is not |
| sufficient to fill the whole image, and thus results in reading outside of |
| the StripByCounts/StripOffsets arrays when using TIFFReadScanline(). Reported |
| by Agostino Sarubbo. Fixes http://bugzilla.maptools.org/show_bug.cgi?id=2608. |
| |
| * libtiff/tif_strip.c: revert the change in TIFFNumberOfStrips() done |
| for http://bugzilla.maptools.org/show_bug.cgi?id=2587 / CVE-2016-9273 since |
| the above change is a better fix that makes it unnecessary. |
| |
| Fixes CVE-2016-10270 |
| |
| Signed-off-by: Peter Korsgaard <peter@korsgaard.com> |
| --- |
| libtiff/tif_dirread.c | 22 ++++++++++------------ |
| libtiff/tif_strip.c | 9 --------- |
| 2 files changed, 25 insertions(+), 21 deletions(-) |
| |
| diff --git a/libtiff/tif_dirread.c b/libtiff/tif_dirread.c |
| index 3eec79c9..570d0c32 100644 |
| --- a/libtiff/tif_dirread.c |
| +++ b/libtiff/tif_dirread.c |
| @@ -5502,8 +5502,7 @@ ChopUpSingleUncompressedStrip(TIFF* tif) |
| uint64 rowblockbytes; |
| uint64 stripbytes; |
| uint32 strip; |
| - uint64 nstrips64; |
| - uint32 nstrips32; |
| + uint32 nstrips; |
| uint32 rowsperstrip; |
| uint64* newcounts; |
| uint64* newoffsets; |
| @@ -5534,18 +5533,17 @@ ChopUpSingleUncompressedStrip(TIFF* tif) |
| return; |
| |
| /* |
| - * never increase the number of strips in an image |
| + * never increase the number of rows per strip |
| */ |
| if (rowsperstrip >= td->td_rowsperstrip) |
| return; |
| - nstrips64 = TIFFhowmany_64(bytecount, stripbytes); |
| - if ((nstrips64==0)||(nstrips64>0xFFFFFFFF)) /* something is wonky, do nothing. */ |
| - return; |
| - nstrips32 = (uint32)nstrips64; |
| + nstrips = TIFFhowmany_32(td->td_imagelength, rowsperstrip); |
| + if( nstrips == 0 ) |
| + return; |
| |
| - newcounts = (uint64*) _TIFFCheckMalloc(tif, nstrips32, sizeof (uint64), |
| + newcounts = (uint64*) _TIFFCheckMalloc(tif, nstrips, sizeof (uint64), |
| "for chopped \"StripByteCounts\" array"); |
| - newoffsets = (uint64*) _TIFFCheckMalloc(tif, nstrips32, sizeof (uint64), |
| + newoffsets = (uint64*) _TIFFCheckMalloc(tif, nstrips, sizeof (uint64), |
| "for chopped \"StripOffsets\" array"); |
| if (newcounts == NULL || newoffsets == NULL) { |
| /* |
| @@ -5562,18 +5560,18 @@ ChopUpSingleUncompressedStrip(TIFF* tif) |
| * Fill the strip information arrays with new bytecounts and offsets |
| * that reflect the broken-up format. |
| */ |
| - for (strip = 0; strip < nstrips32; strip++) { |
| + for (strip = 0; strip < nstrips; strip++) { |
| if (stripbytes > bytecount) |
| stripbytes = bytecount; |
| newcounts[strip] = stripbytes; |
| - newoffsets[strip] = offset; |
| + newoffsets[strip] = stripbytes ? offset : 0; |
| offset += stripbytes; |
| bytecount -= stripbytes; |
| } |
| /* |
| * Replace old single strip info with multi-strip info. |
| */ |
| - td->td_stripsperimage = td->td_nstrips = nstrips32; |
| + td->td_stripsperimage = td->td_nstrips = nstrips; |
| TIFFSetField(tif, TIFFTAG_ROWSPERSTRIP, rowsperstrip); |
| |
| _TIFFfree(td->td_stripbytecount); |
| diff --git a/libtiff/tif_strip.c b/libtiff/tif_strip.c |
| index 4c46ecf5..1676e47d 100644 |
| --- a/libtiff/tif_strip.c |
| +++ b/libtiff/tif_strip.c |
| @@ -63,15 +63,6 @@ TIFFNumberOfStrips(TIFF* tif) |
| TIFFDirectory *td = &tif->tif_dir; |
| uint32 nstrips; |
| |
| - /* If the value was already computed and store in td_nstrips, then return it, |
| - since ChopUpSingleUncompressedStrip might have altered and resized the |
| - since the td_stripbytecount and td_stripoffset arrays to the new value |
| - after the initial affectation of td_nstrips = TIFFNumberOfStrips() in |
| - tif_dirread.c ~line 3612. |
| - See http://bugzilla.maptools.org/show_bug.cgi?id=2587 */ |
| - if( td->td_nstrips ) |
| - return td->td_nstrips; |
| - |
| nstrips = (td->td_rowsperstrip == (uint32) -1 ? 1 : |
| TIFFhowmany_32(td->td_imagelength, td->td_rowsperstrip)); |
| if (td->td_planarconfig == PLANARCONFIG_SEPARATE) |
| -- |
| 2.11.0 |
| |