1 From b18012dae552f85dcc5c57d3bf4e997a15b1cc1c Mon Sep 17 00:00:00 2001 2 From: erouault <erouault> 3 Date: Sun, 27 Dec 2015 16:55:20 +0000 4 Subject: [PATCH] * libtiff/tif_next.c: fix potential out-of-bound write in 5 NeXTDecode() triggered by http://lcamtuf.coredump.cx/afl/vulns/libtiff5.tif 6 (bugzilla #2508) 7 8 --- 9 ChangeLog | 6 ++++++ 10 libtiff/tif_next.c | 10 ++++++++-- 11 2 files changed, 14 insertions(+), 2 deletions(-) 12 13 diff --git a/libtiff/tif_next.c b/libtiff/tif_next.c 14 index dd669cc..0a5b635 100644 15 --- a/libtiff/tif_next.c 16 +++ b/libtiff/tif_next.c 17 @@ -37,7 +37,7 @@ 18 case 0: op[0] = (unsigned char) ((v) << 6); break; \ 19 case 1: op[0] |= (v) << 4; break; \ 20 case 2: op[0] |= (v) << 2; break; \ 21 - case 3: *op++ |= (v); break; \ 22 + case 3: *op++ |= (v); op_offset++; break; \ 23 } \ 24 } 25 26 @@ -106,6 +106,7 @@ NeXTDecode(TIFF* tif, uint8* buf, tmsize_t occ, uint16 s) 27 uint32 imagewidth = tif->tif_dir.td_imagewidth; 28 if( isTiled(tif) ) 29 imagewidth = tif->tif_dir.td_tilewidth; 30 + tmsize_t op_offset = 0; 31 32 /* 33 * The scanline is composed of a sequence of constant 34 @@ -122,10 +123,15 @@ NeXTDecode(TIFF* tif, uint8* buf, tmsize_t occ, uint16 s) 35 * bounds, potentially resulting in a security 36 * issue. 37 */ 38 - while (n-- > 0 && npixels < imagewidth) 39 + while (n-- > 0 && npixels < imagewidth && op_offset < scanline) 40 SETPIXEL(op, grey); 41 if (npixels >= imagewidth) 42 break; 43 + if (op_offset >= scanline ) { 44 + TIFFErrorExt(tif->tif_clientdata, module, "Invalid data for scanline %ld", 45 + (long) tif->tif_row); 46 + return (0); 47 + } 48 if (cc == 0) 49 goto bad; 50 n = *bp++, cc--; 51
