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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 <chee.yang.lee@intel.com>
[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 <sulau@freenet.de>
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),
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