28 lines
1.4 KiB
Diff
28 lines
1.4 KiB
Diff
From f80ad18afae2230c2c1802c7d829100af646874e Mon Sep 17 00:00:00 2001
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From: Stanislav Malyshev <stas@php.net>
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Date: Mon, 29 Apr 2019 23:38:12 -0700
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Subject: [PATCH] Fix bug #77950 - Heap-buffer-overflow in _estrndup via
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exif_process_IFD_TAG
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I do not completely understand what is going on there, but I am pretty
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sure dir_entry <= offset_base if not a normal situation, so we better not
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to rely on such dir_entry.
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---
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ext/exif/exif.c | 2 +-
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1 files changed, 1 insertions(+), 1 deletions(-)
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diff --git a/ext/exif/exif.c b/ext/exif/exif.c
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index a763f6c..d174def 100644
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--- a/ext/exif/exif.c
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+++ b/ext/exif/exif.c
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@@ -2891,7 +2891,7 @@ static int exif_process_IFD_TAG(image_info_type *ImageInfo, char *dir_entry, cha
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offset_base is ImageInfo->file.list[sn].data-dir_offset
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dir_entry - offset_base is dir_offset+2+i*12
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*/
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- if (byte_count > IFDlength || offset_val > IFDlength-byte_count || value_ptr < dir_entry || offset_val < (size_t)(dir_entry-offset_base)) {
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+ if (byte_count > IFDlength || offset_val > IFDlength-byte_count || value_ptr < dir_entry || offset_val < (size_t)(dir_entry-offset_base) || dir_entry <= offset_base) {
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/* It is important to check for IMAGE_FILETYPE_TIFF
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* JPEG does not use absolute pointers instead its pointers are
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* relative to the start of the TIFF header in APP1 section. */
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