From 122da5cec495fc8ddfd880327e7c3ed0dc70e04f Mon Sep 17 00:00:00 2001 From: Joe Slater Date: Wed, 18 Jul 2018 11:25:00 -0700 Subject: tiff: security fix CVE-2018-7456 NULL pointer use as described at nvd.nist.gov/vuln/detail/CVE-2018-7456. Signed-off-by: Joe Slater Signed-off-by: Ross Burton --- .../libtiff/files/CVE-2018-7456.patch | 178 +++++++++++++++++++++ meta/recipes-multimedia/libtiff/tiff_4.0.9.bb | 1 + 2 files changed, 179 insertions(+) create mode 100644 meta/recipes-multimedia/libtiff/files/CVE-2018-7456.patch (limited to 'meta/recipes-multimedia/libtiff') diff --git a/meta/recipes-multimedia/libtiff/files/CVE-2018-7456.patch b/meta/recipes-multimedia/libtiff/files/CVE-2018-7456.patch new file mode 100644 index 0000000000..2c11f93d13 --- /dev/null +++ b/meta/recipes-multimedia/libtiff/files/CVE-2018-7456.patch @@ -0,0 +1,178 @@ +From be4c85b16e8801a16eec25e80eb9f3dd6a96731b Mon Sep 17 00:00:00 2001 +From: Hugo Lefeuvre +Date: Sun, 8 Apr 2018 14:07:08 -0400 +Subject: [PATCH] Fix NULL pointer dereference in TIFFPrintDirectory + +The TIFFPrintDirectory function relies on the following assumptions, +supposed to be guaranteed by the specification: + +(a) A Transfer Function field is only present if the TIFF file has + photometric type < 3. + +(b) If SamplesPerPixel > Color Channels, then the ExtraSamples field + has count SamplesPerPixel - (Color Channels) and contains + information about supplementary channels. + +While respect of (a) and (b) are essential for the well functioning of +TIFFPrintDirectory, no checks are realized neither by the callee nor +by TIFFPrintDirectory itself. Hence, following scenarios might happen +and trigger the NULL pointer dereference: + +(1) TIFF File of photometric type 4 or more has illegal Transfer + Function field. + +(2) TIFF File has photometric type 3 or less and defines a + SamplesPerPixel field such that SamplesPerPixel > Color Channels + without defining all extra samples in the ExtraSamples fields. + +In this patch, we address both issues with respect of the following +principles: + +(A) In the case of (1), the defined transfer table should be printed + safely even if it isn't 'legal'. This allows us to avoid expensive + checks in TIFFPrintDirectory. Also, it is quite possible that + an alternative photometric type would be developed (not part of the + standard) and would allow definition of Transfer Table. We want + libtiff to be able to handle this scenario out of the box. + +(B) In the case of (2), the transfer table should be printed at its + right size, that is if TIFF file has photometric type Palette + then the transfer table should have one row and not three, even + if two extra samples are declared. + +In order to fulfill (A) we simply add a new 'i < 3' end condition to +the broken TIFFPrintDirectory loop. This makes sure that in any case +where (b) would be respected but not (a), everything stays fine. + +(B) is fulfilled by the loop condition +'i < td->td_samplesperpixel - td->td_extrasamples'. This is enough as +long as (b) is respected. + +Naturally, we also make sure (b) is respected. This is done in the +TIFFReadDirectory function by making sure any non-color channel is +counted in ExtraSamples. + +This commit addresses CVE-2018-7456. + +--- +CVE: CVE-2018-7456 + +Upstream-Status: Backport [gitlab.com/libtiff/libtiff/commit/be4c85b...] + +Signed-off-by: Joe Slater + +--- + libtiff/tif_dirread.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++++ + libtiff/tif_print.c | 2 +- + 2 files changed, 63 insertions(+), 1 deletion(-) + +diff --git a/libtiff/tif_dirread.c b/libtiff/tif_dirread.c +index 6baa7b3..af5b84a 100644 +--- a/libtiff/tif_dirread.c ++++ b/libtiff/tif_dirread.c +@@ -165,6 +165,7 @@ static int TIFFFetchStripThing(TIFF* tif, TIFFDirEntry* dir, uint32 nstrips, uin + static int TIFFFetchSubjectDistance(TIFF*, TIFFDirEntry*); + static void ChopUpSingleUncompressedStrip(TIFF*); + static uint64 TIFFReadUInt64(const uint8 *value); ++static int _TIFFGetMaxColorChannels(uint16 photometric); + + static int _TIFFFillStrilesInternal( TIFF *tif, int loadStripByteCount ); + +@@ -3505,6 +3506,35 @@ static void TIFFReadDirEntryOutputErr(TIFF* tif, enum TIFFReadDirEntryErr err, c + } + + /* ++ * Return the maximum number of color channels specified for a given photometric ++ * type. 0 is returned if photometric type isn't supported or no default value ++ * is defined by the specification. ++ */ ++static int _TIFFGetMaxColorChannels( uint16 photometric ) ++{ ++ switch (photometric) { ++ case PHOTOMETRIC_PALETTE: ++ case PHOTOMETRIC_MINISWHITE: ++ case PHOTOMETRIC_MINISBLACK: ++ return 1; ++ case PHOTOMETRIC_YCBCR: ++ case PHOTOMETRIC_RGB: ++ case PHOTOMETRIC_CIELAB: ++ return 3; ++ case PHOTOMETRIC_SEPARATED: ++ case PHOTOMETRIC_MASK: ++ return 4; ++ case PHOTOMETRIC_LOGL: ++ case PHOTOMETRIC_LOGLUV: ++ case PHOTOMETRIC_CFA: ++ case PHOTOMETRIC_ITULAB: ++ case PHOTOMETRIC_ICCLAB: ++ default: ++ return 0; ++ } ++} ++ ++/* + * Read the next TIFF directory from a file and convert it to the internal + * format. We read directories sequentially. + */ +@@ -3520,6 +3550,7 @@ TIFFReadDirectory(TIFF* tif) + uint32 fii=FAILED_FII; + toff_t nextdiroff; + int bitspersample_read = FALSE; ++ int color_channels; + + tif->tif_diroff=tif->tif_nextdiroff; + if (!TIFFCheckDirOffset(tif,tif->tif_nextdiroff)) +@@ -4024,6 +4055,37 @@ TIFFReadDirectory(TIFF* tif) + } + } + } ++ ++ /* ++ * Make sure all non-color channels are extrasamples. ++ * If it's not the case, define them as such. ++ */ ++ color_channels = _TIFFGetMaxColorChannels(tif->tif_dir.td_photometric); ++ if (color_channels && tif->tif_dir.td_samplesperpixel - tif->tif_dir.td_extrasamples > color_channels) { ++ uint16 old_extrasamples; ++ uint16 *new_sampleinfo; ++ ++ TIFFWarningExt(tif->tif_clientdata,module, "Sum of Photometric type-related " ++ "color channels and ExtraSamples doesn't match SamplesPerPixel. " ++ "Defining non-color channels as ExtraSamples."); ++ ++ old_extrasamples = tif->tif_dir.td_extrasamples; ++ tif->tif_dir.td_extrasamples = (tif->tif_dir.td_samplesperpixel - color_channels); ++ ++ // sampleinfo should contain information relative to these new extra samples ++ new_sampleinfo = (uint16*) _TIFFcalloc(tif->tif_dir.td_extrasamples, sizeof(uint16)); ++ if (!new_sampleinfo) { ++ TIFFErrorExt(tif->tif_clientdata, module, "Failed to allocate memory for " ++ "temporary new sampleinfo array (%d 16 bit elements)", ++ tif->tif_dir.td_extrasamples); ++ goto bad; ++ } ++ ++ memcpy(new_sampleinfo, tif->tif_dir.td_sampleinfo, old_extrasamples * sizeof(uint16)); ++ _TIFFsetShortArray(&tif->tif_dir.td_sampleinfo, new_sampleinfo, tif->tif_dir.td_extrasamples); ++ _TIFFfree(new_sampleinfo); ++ } ++ + /* + * Verify Palette image has a Colormap. + */ +diff --git a/libtiff/tif_print.c b/libtiff/tif_print.c +index 8deceb2..1d86adb 100644 +--- a/libtiff/tif_print.c ++++ b/libtiff/tif_print.c +@@ -544,7 +544,7 @@ TIFFPrintDirectory(TIFF* tif, FILE* fd, long flags) + uint16 i; + fprintf(fd, " %2ld: %5u", + l, td->td_transferfunction[0][l]); +- for (i = 1; i < td->td_samplesperpixel; i++) ++ for (i = 1; i < td->td_samplesperpixel - td->td_extrasamples && i < 3; i++) + fprintf(fd, " %5u", + td->td_transferfunction[i][l]); + fputc('\n', fd); +-- +1.7.9.5 + diff --git a/meta/recipes-multimedia/libtiff/tiff_4.0.9.bb b/meta/recipes-multimedia/libtiff/tiff_4.0.9.bb index 53b2b81ec2..fa64d11216 100644 --- a/meta/recipes-multimedia/libtiff/tiff_4.0.9.bb +++ b/meta/recipes-multimedia/libtiff/tiff_4.0.9.bb @@ -11,6 +11,7 @@ SRC_URI = "http://download.osgeo.org/libtiff/tiff-${PV}.tar.gz \ file://CVE-2018-5784.patch \ file://CVE-2018-10963.patch \ file://CVE-2018-8905.patch \ + file://CVE-2018-7456.patch \ " SRC_URI[md5sum] = "54bad211279cc93eb4fca31ba9bfdc79" -- cgit 1.2.3-korg