CVE: CVE-2023-6277 Upstream-Status: Backport [upstream : https://gitlab.com/libtiff/libtiff/-/commit/5320c9d89c054fa805d037d84c57da874470b01a ubuntu : http://archive.ubuntu.com/ubuntu/pool/main/t/tiff/tiff_4.3.0-6ubuntu0.8.debian.tar.xz ] Signed-off-by: Lee Chee Yang [Ubuntu note: Backport of the following patch from upstream, with a few changes to match the current version of the file in the present Ubuntu release: . using TIFFWarningExt instead of TIFFWarningExtR (the latter did not exist yet); . calling _TIFFfree(data) instead of _TIFFfreeExt(tif, data) (the latter did not exist yet); -- Rodrigo Figueiredo Zaiden] Backport of: From 5320c9d89c054fa805d037d84c57da874470b01a Mon Sep 17 00:00:00 2001 From: Su Laus Date: Tue, 31 Oct 2023 15:43:29 +0000 Subject: [PATCH] Prevent some out-of-memory attacks Some small fuzzer files fake large amounts of data and provoke out-of-memory situations. For non-compressed data content / tags, out-of-memory can be prevented by comparing with the file size. At image reading, data size of some tags / data structures (StripByteCounts, StripOffsets, StripArray, TIFF directory) is compared with file size to prevent provoked out-of-memory attacks. See issue https://gitlab.com/libtiff/libtiff/-/issues/614#note_1602683857 --- libtiff/tif_dirread.c | 92 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 90 insertions(+), 2 deletions(-) --- tiff-4.3.0.orig/libtiff/tif_dirread.c +++ tiff-4.3.0/libtiff/tif_dirread.c @@ -866,6 +866,21 @@ static enum TIFFReadDirEntryErr TIFFRead datasize=(*count)*typesize; assert((tmsize_t)datasize>0); + /* Before allocating a huge amount of memory for corrupted files, check if + * size of requested memory is not greater than file size. + */ + uint64_t filesize = TIFFGetFileSize(tif); + if (datasize > filesize) + { + TIFFWarningExt(tif->tif_clientdata, "ReadDirEntryArray", + "Requested memory size for tag %d (0x%x) %" PRIu32 + " is greather than filesize %" PRIu64 + ". Memory not allocated, tag not read", + direntry->tdir_tag, direntry->tdir_tag, datasize, + filesize); + return (TIFFReadDirEntryErrAlloc); + } + if( isMapped(tif) && datasize > (uint64_t)tif->tif_size ) return TIFFReadDirEntryErrIo; @@ -4593,6 +4608,20 @@ EstimateStripByteCounts(TIFF* tif, TIFFD if( !_TIFFFillStrilesInternal( tif, 0 ) ) return -1; + /* Before allocating a huge amount of memory for corrupted files, check if + * size of requested memory is not greater than file size. */ + uint64_t filesize = TIFFGetFileSize(tif); + uint64_t allocsize = (uint64_t)td->td_nstrips * sizeof(uint64_t); + if (allocsize > filesize) + { + TIFFWarningExt(tif->tif_clientdata, module, + "Requested memory size for StripByteCounts of %" PRIu64 + " is greather than filesize %" PRIu64 + ". Memory not allocated", + allocsize, filesize); + return -1; + } + if (td->td_stripbytecount_p) _TIFFfree(td->td_stripbytecount_p); td->td_stripbytecount_p = (uint64_t*) @@ -4603,9 +4632,7 @@ EstimateStripByteCounts(TIFF* tif, TIFFD if (td->td_compression != COMPRESSION_NONE) { uint64_t space; - uint64_t filesize; uint16_t n; - filesize = TIFFGetFileSize(tif); if (!(tif->tif_flags&TIFF_BIGTIFF)) space=sizeof(TIFFHeaderClassic)+2+dircount*12+4; else @@ -4913,6 +4940,20 @@ TIFFFetchDirectory(TIFF* tif, uint64_t d dircount16 = (uint16_t)dircount64; dirsize = 20; } + /* Before allocating a huge amount of memory for corrupted files, check + * if size of requested memory is not greater than file size. */ + uint64_t filesize = TIFFGetFileSize(tif); + uint64_t allocsize = (uint64_t)dircount16 * dirsize; + if (allocsize > filesize) + { + TIFFWarningExt( + tif->tif_clientdata, module, + "Requested memory size for TIFF directory of %" PRIu64 + " is greather than filesize %" PRIu64 + ". Memory not allocated, TIFF directory not read", + allocsize, filesize); + return 0; + } origdir = _TIFFCheckMalloc(tif, dircount16, dirsize, "to read TIFF directory"); if (origdir == NULL) @@ -5016,6 +5057,20 @@ TIFFFetchDirectory(TIFF* tif, uint64_t d "Sanity check on directory count failed, zero tag directories not supported"); return 0; } + /* Before allocating a huge amount of memory for corrupted files, check + * if size of requested memory is not greater than file size. */ + uint64_t filesize = TIFFGetFileSize(tif); + uint64_t allocsize = (uint64_t)dircount16 * dirsize; + if (allocsize > filesize) + { + TIFFWarningExt( + tif->tif_clientdata, module, + "Requested memory size for TIFF directory of %" PRIu64 + " is greather than filesize %" PRIu64 + ". Memory not allocated, TIFF directory not read", + allocsize, filesize); + return 0; + } origdir = _TIFFCheckMalloc(tif, dircount16, dirsize, "to read TIFF directory"); @@ -5059,6 +5114,8 @@ TIFFFetchDirectory(TIFF* tif, uint64_t d } } } + /* No check against filesize needed here because "dir" should have same size + * than "origdir" checked above. */ dir = (TIFFDirEntry*)_TIFFCheckMalloc(tif, dircount16, sizeof(TIFFDirEntry), "to read TIFF directory"); @@ -5853,6 +5910,20 @@ TIFFFetchStripThing(TIFF* tif, TIFFDirEn return(0); } + /* Before allocating a huge amount of memory for corrupted files, check + * if size of requested memory is not greater than file size. */ + uint64_t filesize = TIFFGetFileSize(tif); + uint64_t allocsize = (uint64_t)nstrips * sizeof(uint64_t); + if (allocsize > filesize) + { + TIFFWarningExt(tif->tif_clientdata, module, + "Requested memory size for StripArray of %" PRIu64 + " is greather than filesize %" PRIu64 + ". Memory not allocated", + allocsize, filesize); + _TIFFfree(data); + return (0); + } resizeddata=(uint64_t*)_TIFFCheckMalloc(tif, nstrips, sizeof(uint64_t), "for strip array"); if (resizeddata==0) { _TIFFfree(data); @@ -5948,6 +6019,23 @@ static void allocChoppedUpStripArrays(TI } bytecount = last_offset + last_bytecount - offset; + /* Before allocating a huge amount of memory for corrupted files, check if + * size of StripByteCount and StripOffset tags is not greater than + * file size. + */ + uint64_t allocsize = (uint64_t)nstrips * sizeof(uint64_t) * 2; + uint64_t filesize = TIFFGetFileSize(tif); + if (allocsize > filesize) + { + TIFFWarningExt(tif->tif_clientdata, "allocChoppedUpStripArrays", + "Requested memory size for StripByteCount and " + "StripOffsets %" PRIu64 + " is greather than filesize %" PRIu64 + ". Memory not allocated", + allocsize, filesize); + return; + } + newcounts = (uint64_t*) _TIFFCheckMalloc(tif, nstrips, sizeof (uint64_t), "for chopped \"StripByteCounts\" array"); newoffsets = (uint64_t*) _TIFFCheckMalloc(tif, nstrips, sizeof (uint64_t),