| From 3cfd62d77c2a7e147a05bd678524c345fa9c2bb8 Mon Sep 17 00:00:00 2001 |
| From: erouault <erouault> |
| Date: Wed, 11 Jan 2017 13:28:01 +0000 |
| Subject: [PATCH] * libtiff/tif_dirread.c: avoid division by floating point 0 |
| in TIFFReadDirEntryCheckedRational() and TIFFReadDirEntryCheckedSrational(), |
| and return 0 in that case (instead of infinity as before presumably) |
| Apparently some sanitizers do not like those divisions by zero. Fixes |
| http://bugzilla.maptools.org/show_bug.cgi?id=2644 |
| |
| Fixes CVE-2017-7598 |
| |
| Signed-off-by: Peter Korsgaard <peter@korsgaard.com> |
| --- |
| libtiff/tif_dirread.c | 10 ++++++++-- |
| 1 file changed, 16 insertions(+), 2 deletions(-) |
| |
| diff --git a/libtiff/tif_dirread.c b/libtiff/tif_dirread.c |
| index 570d0c32..8a1e42aa 100644 |
| --- a/libtiff/tif_dirread.c |
| +++ b/libtiff/tif_dirread.c |
| @@ -2872,7 +2872,10 @@ static enum TIFFReadDirEntryErr TIFFReadDirEntryCheckedRational(TIFF* tif, TIFFD |
| m.l = direntry->tdir_offset.toff_long8; |
| if (tif->tif_flags&TIFF_SWAB) |
| TIFFSwabArrayOfLong(m.i,2); |
| - if (m.i[0]==0) |
| + /* Not completely sure what we should do when m.i[1]==0, but some */ |
| + /* sanitizers do not like division by 0.0: */ |
| + /* http://bugzilla.maptools.org/show_bug.cgi?id=2644 */ |
| + if (m.i[0]==0 || m.i[1]==0) |
| *value=0.0; |
| else |
| *value=(double)m.i[0]/(double)m.i[1]; |
| @@ -2900,7 +2903,10 @@ static enum TIFFReadDirEntryErr TIFFReadDirEntryCheckedSrational(TIFF* tif, TIFF |
| m.l=direntry->tdir_offset.toff_long8; |
| if (tif->tif_flags&TIFF_SWAB) |
| TIFFSwabArrayOfLong(m.i,2); |
| - if ((int32)m.i[0]==0) |
| + /* Not completely sure what we should do when m.i[1]==0, but some */ |
| + /* sanitizers do not like division by 0.0: */ |
| + /* http://bugzilla.maptools.org/show_bug.cgi?id=2644 */ |
| + if ((int32)m.i[0]==0 || m.i[1]==0) |
| *value=0.0; |
| else |
| *value=(double)((int32)m.i[0])/(double)m.i[1]; |
| -- |
| 2.11.0 |
| |
