From f9bb9f263fb00f0603ecbefa8957cad24168cbff Mon Sep 17 00:00:00 2001 From: Dan Fandrich Date: Wed, 4 Jul 2018 11:06:09 +0200 Subject: [PATCH] Fix a buffer read overflow in exif_entry_get_value While parsing EXIF_TAG_FOCAL_LENGTH it was possible to read 8 bytes past the end of a heap buffer. This was detected by the OSS Fuzz project. Patch from Google. Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=7344 and https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=14543 --- libexif/exif-entry.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/libexif/exif-entry.c b/libexif/exif-entry.c index 61260d3c..a224ac2e 100644 --- a/libexif/exif-entry.c +++ b/libexif/exif-entry.c @@ -1040,12 +1040,12 @@ exif_entry_get_value (ExifEntry *e, char *val, unsigned int maxlen) d = 0.; entry = exif_content_get_entry ( e->parent->parent->ifd[EXIF_IFD_0], EXIF_TAG_MAKE); - if (entry && entry->data && + if (entry && entry->data && entry->size >= 7 && !strncmp ((char *)entry->data, "Minolta", 7)) { entry = exif_content_get_entry ( e->parent->parent->ifd[EXIF_IFD_0], EXIF_TAG_MODEL); - if (entry && entry->data) { + if (entry && entry->data && entry->size >= 8) { if (!strncmp ((char *)entry->data, "DiMAGE 7", 8)) d = 3.9; else if (!strncmp ((char *)entry->data, "DiMAGE 5", 8))