| From b18012dae552f85dcc5c57d3bf4e997a15b1cc1c Mon Sep 17 00:00:00 2001 |
| From: erouault <erouault> |
| Date: Sun, 27 Dec 2015 16:55:20 +0000 |
| Subject: [PATCH] * libtiff/tif_next.c: fix potential out-of-bound write in |
| NeXTDecode() triggered by http://lcamtuf.coredump.cx/afl/vulns/libtiff5.tif |
| (bugzilla #2508) |
| |
| --- |
| ChangeLog | 6 ++++++ |
| libtiff/tif_next.c | 10 ++++++++-- |
| 2 files changed, 14 insertions(+), 2 deletions(-) |
| |
| diff --git a/libtiff/tif_next.c b/libtiff/tif_next.c |
| index dd669cc..0a5b635 100644 |
| --- a/libtiff/tif_next.c |
| +++ b/libtiff/tif_next.c |
| @@ -37,7 +37,7 @@ |
| case 0: op[0] = (unsigned char) ((v) << 6); break; \ |
| case 1: op[0] |= (v) << 4; break; \ |
| case 2: op[0] |= (v) << 2; break; \ |
| - case 3: *op++ |= (v); break; \ |
| + case 3: *op++ |= (v); op_offset++; break; \ |
| } \ |
| } |
| |
| @@ -106,6 +106,7 @@ NeXTDecode(TIFF* tif, uint8* buf, tmsize_t occ, uint16 s) |
| uint32 imagewidth = tif->tif_dir.td_imagewidth; |
| if( isTiled(tif) ) |
| imagewidth = tif->tif_dir.td_tilewidth; |
| + tmsize_t op_offset = 0; |
| |
| /* |
| * The scanline is composed of a sequence of constant |
| @@ -122,10 +123,15 @@ NeXTDecode(TIFF* tif, uint8* buf, tmsize_t occ, uint16 s) |
| * bounds, potentially resulting in a security |
| * issue. |
| */ |
| - while (n-- > 0 && npixels < imagewidth) |
| + while (n-- > 0 && npixels < imagewidth && op_offset < scanline) |
| SETPIXEL(op, grey); |
| if (npixels >= imagewidth) |
| break; |
| + if (op_offset >= scanline ) { |
| + TIFFErrorExt(tif->tif_clientdata, module, "Invalid data for scanline %ld", |
| + (long) tif->tif_row); |
| + return (0); |
| + } |
| if (cc == 0) |
| goto bad; |
| n = *bp++, cc--; |
