Brad Bishop | 316dfdd | 2018-06-25 12:45:53 -0400 | [diff] [blame] | 1 | From 6cdea15213be6b67d9f8380c7bb40e325d3adace Mon Sep 17 00:00:00 2001 |
| 2 | From: Nathan Baker <nathanb@lenovo-chrome.com> |
| 3 | Date: Tue, 6 Feb 2018 10:13:57 -0500 |
| 4 | Subject: [PATCH] Fix for bug 2772 |
| 5 | |
| 6 | It is possible to craft a TIFF document where the IFD list is circular, |
| 7 | leading to an infinite loop while traversing the chain. The libtiff |
| 8 | directory reader has a failsafe that will break out of this loop after |
| 9 | reading 65535 directory entries, but it will continue processing, |
| 10 | consuming time and resources to process what is essentially a bogus TIFF |
| 11 | document. |
| 12 | |
| 13 | This change fixes the above behavior by breaking out of processing when |
| 14 | a TIFF document has >= 65535 directories and terminating with an error. |
| 15 | |
| 16 | Upstream-Status: Backport |
| 17 | [https://gitlab.com/libtiff/libtiff/commit/473851d211cf8805a161820337ca74cc9615d6ef] |
| 18 | |
| 19 | CVE: CVE-2018-5784 |
| 20 | |
| 21 | Signed-off-by: Yi Zhao <yi.zhao@windriver.com> |
| 22 | --- |
| 23 | contrib/addtiffo/tif_overview.c | 14 +++++++++++++- |
| 24 | tools/tiff2pdf.c | 10 ++++++++++ |
| 25 | tools/tiffcrop.c | 13 +++++++++++-- |
| 26 | 3 files changed, 34 insertions(+), 3 deletions(-) |
| 27 | |
| 28 | diff --git a/contrib/addtiffo/tif_overview.c b/contrib/addtiffo/tif_overview.c |
| 29 | index c61ffbb..03b3573 100644 |
| 30 | --- a/contrib/addtiffo/tif_overview.c |
| 31 | +++ b/contrib/addtiffo/tif_overview.c |
| 32 | @@ -65,6 +65,8 @@ |
| 33 | # define MAX(a,b) ((a>b) ? a : b) |
| 34 | #endif |
| 35 | |
| 36 | +#define TIFF_DIR_MAX 65534 |
| 37 | + |
| 38 | void TIFFBuildOverviews( TIFF *, int, int *, int, const char *, |
| 39 | int (*)(double,void*), void * ); |
| 40 | |
| 41 | @@ -91,6 +93,7 @@ uint32 TIFF_WriteOverview( TIFF *hTIFF, uint32 nXSize, uint32 nYSize, |
| 42 | { |
| 43 | toff_t nBaseDirOffset; |
| 44 | toff_t nOffset; |
| 45 | + tdir_t iNumDir; |
| 46 | |
| 47 | (void) bUseSubIFDs; |
| 48 | |
| 49 | @@ -147,7 +150,16 @@ uint32 TIFF_WriteOverview( TIFF *hTIFF, uint32 nXSize, uint32 nYSize, |
| 50 | return 0; |
| 51 | |
| 52 | TIFFWriteDirectory( hTIFF ); |
| 53 | - TIFFSetDirectory( hTIFF, (tdir_t) (TIFFNumberOfDirectories(hTIFF)-1) ); |
| 54 | + iNumDir = TIFFNumberOfDirectories(hTIFF); |
| 55 | + if( iNumDir > TIFF_DIR_MAX ) |
| 56 | + { |
| 57 | + TIFFErrorExt( TIFFClientdata(hTIFF), |
| 58 | + "TIFF_WriteOverview", |
| 59 | + "File `%s' has too many directories.\n", |
| 60 | + TIFFFileName(hTIFF) ); |
| 61 | + exit(-1); |
| 62 | + } |
| 63 | + TIFFSetDirectory( hTIFF, (tdir_t) (iNumDir - 1) ); |
| 64 | |
| 65 | nOffset = TIFFCurrentDirOffset( hTIFF ); |
| 66 | |
| 67 | diff --git a/tools/tiff2pdf.c b/tools/tiff2pdf.c |
| 68 | index 0b5973e..ef5d6a0 100644 |
| 69 | --- a/tools/tiff2pdf.c |
| 70 | +++ b/tools/tiff2pdf.c |
| 71 | @@ -68,6 +68,8 @@ extern int getopt(int, char**, char*); |
| 72 | |
| 73 | #define PS_UNIT_SIZE 72.0F |
| 74 | |
| 75 | +#define TIFF_DIR_MAX 65534 |
| 76 | + |
| 77 | /* This type is of PDF color spaces. */ |
| 78 | typedef enum { |
| 79 | T2P_CS_BILEVEL = 0x01, /* Bilevel, black and white */ |
| 80 | @@ -1051,6 +1053,14 @@ void t2p_read_tiff_init(T2P* t2p, TIFF* input){ |
| 81 | float* tiff_transferfunction[3]; |
| 82 | |
| 83 | directorycount=TIFFNumberOfDirectories(input); |
| 84 | + if(directorycount > TIFF_DIR_MAX) { |
| 85 | + TIFFError( |
| 86 | + TIFF2PDF_MODULE, |
| 87 | + "TIFF contains too many directories, %s", |
| 88 | + TIFFFileName(input)); |
| 89 | + t2p->t2p_error = T2P_ERR_ERROR; |
| 90 | + return; |
| 91 | + } |
| 92 | t2p->tiff_pages = (T2P_PAGE*) _TIFFmalloc(TIFFSafeMultiply(tmsize_t,directorycount,sizeof(T2P_PAGE))); |
| 93 | if(t2p->tiff_pages==NULL){ |
| 94 | TIFFError( |
| 95 | diff --git a/tools/tiffcrop.c b/tools/tiffcrop.c |
| 96 | index c69177e..c60cb38 100644 |
| 97 | --- a/tools/tiffcrop.c |
| 98 | +++ b/tools/tiffcrop.c |
| 99 | @@ -217,6 +217,8 @@ extern int getopt(int argc, char * const argv[], const char *optstring); |
| 100 | #define DUMP_TEXT 1 |
| 101 | #define DUMP_RAW 2 |
| 102 | |
| 103 | +#define TIFF_DIR_MAX 65534 |
| 104 | + |
| 105 | /* Offsets into buffer for margins and fixed width and length segments */ |
| 106 | struct offset { |
| 107 | uint32 tmargin; |
| 108 | @@ -2233,7 +2235,7 @@ main(int argc, char* argv[]) |
| 109 | pageNum = -1; |
| 110 | else |
| 111 | total_images = 0; |
| 112 | - /* read multiple input files and write to output file(s) */ |
| 113 | + /* Read multiple input files and write to output file(s) */ |
| 114 | while (optind < argc - 1) |
| 115 | { |
| 116 | in = TIFFOpen (argv[optind], "r"); |
| 117 | @@ -2241,7 +2243,14 @@ main(int argc, char* argv[]) |
| 118 | return (-3); |
| 119 | |
| 120 | /* If only one input file is specified, we can use directory count */ |
| 121 | - total_images = TIFFNumberOfDirectories(in); |
| 122 | + total_images = TIFFNumberOfDirectories(in); |
| 123 | + if (total_images > TIFF_DIR_MAX) |
| 124 | + { |
| 125 | + TIFFError (TIFFFileName(in), "File contains too many directories"); |
| 126 | + if (out != NULL) |
| 127 | + (void) TIFFClose(out); |
| 128 | + return (1); |
| 129 | + } |
| 130 | if (image_count == 0) |
| 131 | { |
| 132 | dirnum = 0; |
| 133 | -- |
| 134 | 2.7.4 |
| 135 | |