From a04b4c4aec3bbfbbde9602ddb4e00809a1a4f92c Mon Sep 17 00:00:00 2001 From: Young_X Date: Sat, 8 Sep 2018 14:46:27 +0800 Subject: [PATCH] (CVE-2018-17100) avoid potential int32 overflows in multiply_ms() (cherry picked from commit 6da1fb3f64d43be37e640efbec60400d1f1ac39e) --- tools/ppm2tiff.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/tools/ppm2tiff.c b/tools/ppm2tiff.c index 91415e96..81ffa3db 100644 --- a/tools/ppm2tiff.c +++ b/tools/ppm2tiff.c @@ -72,15 +72,16 @@ BadPPM(char* file) exit(-2); } + +#define TIFF_SIZE_T_MAX ((size_t) ~ ((size_t)0)) +#define TIFF_TMSIZE_T_MAX (tmsize_t)(TIFF_SIZE_T_MAX >> 1) + static tmsize_t multiply_ms(tmsize_t m1, tmsize_t m2) { - tmsize_t bytes = m1 * m2; - - if (m1 && bytes / m1 != m2) - bytes = 0; - - return bytes; + if( m1 == 0 || m2 > TIFF_TMSIZE_T_MAX / m1 ) + return 0; + return m1 * m2; } int