170 lines
7.3 KiB
Diff
170 lines
7.3 KiB
Diff
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(-)
|
|
|
|
diff --git a/libtiff/tif_dirread.c b/libtiff/tif_dirread.c
|
|
index 2c49dc6a..58a42760 100644
|
|
--- a/libtiff/tif_dirread.c
|
|
+++ b/libtiff/tif_dirread.c
|
|
@@ -1308,6 +1308,21 @@ TIFFReadDirEntryArrayWithLimit(TIFF *tif, TIFFDirEntry *direntry,
|
|
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)
|
|
+ {
|
|
+ TIFFWarningExtR(tif, "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;
|
|
|
|
@@ -5266,6 +5281,20 @@ static int EstimateStripByteCounts(TIFF *tif, TIFFDirEntry *dir,
|
|
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)
|
|
+ {
|
|
+ TIFFWarningExtR(tif, 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)
|
|
_TIFFfreeExt(tif, td->td_stripbytecount_p);
|
|
td->td_stripbytecount_p = (uint64_t *)_TIFFCheckMalloc(
|
|
@@ -5276,9 +5305,7 @@ static int EstimateStripByteCounts(TIFF *tif, TIFFDirEntry *dir,
|
|
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
|
|
@@ -5807,6 +5834,20 @@ static uint16_t TIFFFetchDirectory(TIFF *tif, uint64_t diroff,
|
|
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)
|
|
+ {
|
|
+ TIFFWarningExtR(
|
|
+ tif, 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)
|
|
@@ -5921,6 +5962,20 @@ static uint16_t TIFFFetchDirectory(TIFF *tif, uint64_t diroff,
|
|
"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)
|
|
+ {
|
|
+ TIFFWarningExtR(
|
|
+ tif, 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)
|
|
@@ -5968,6 +6023,8 @@ static uint16_t TIFFFetchDirectory(TIFF *tif, uint64_t diroff,
|
|
}
|
|
}
|
|
}
|
|
+ /* 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");
|
|
if (dir == 0)
|
|
@@ -7164,6 +7221,20 @@ static int TIFFFetchStripThing(TIFF *tif, TIFFDirEntry *dir, uint32_t nstrips,
|
|
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)
|
|
+ {
|
|
+ TIFFWarningExtR(tif, module,
|
|
+ "Requested memory size for StripArray of %" PRIu64
|
|
+ " is greather than filesize %" PRIu64
|
|
+ ". Memory not allocated",
|
|
+ allocsize, filesize);
|
|
+ _TIFFfreeExt(tif, data);
|
|
+ return (0);
|
|
+ }
|
|
resizeddata = (uint64_t *)_TIFFCheckMalloc(
|
|
tif, nstrips, sizeof(uint64_t), "for strip array");
|
|
if (resizeddata == 0)
|
|
@@ -7263,6 +7334,23 @@ static void allocChoppedUpStripArrays(TIFF *tif, uint32_t nstrips,
|
|
}
|
|
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)
|
|
+ {
|
|
+ TIFFWarningExtR(tif, "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");
|
|
--
|
|
GitLab
|
|
|