33 lines
1.1 KiB
Diff
33 lines
1.1 KiB
Diff
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From 9266d14b5ca4e29b970fa03272318e5f99386e06 Mon Sep 17 00:00:00 2001
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From: Marcus Meissner <marcus@jet.franken.de>
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Date: Thu, 5 Nov 2020 09:50:08 +0100
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Subject: [PATCH] fixed a incorrect overflow check that could be optimized
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away.
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inspired by:
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https://android.googlesource.com/platform/external/libexif/+/8e7345f3bc0bad06ac369d6cbc1124c8ceaf7d4b
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https://source.android.com/security/bulletin/2020-11-01
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CVE-2020-0452
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---
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NEWS | 3 ++-
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libexif/exif-entry.c | 4 ++--
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2 files changed, 4 insertions(+), 3 deletions(-)
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diff --git a/libexif/exif-entry.c b/libexif/exif-entry.c
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index 3fc0ff9..4b866ce 100644
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--- a/libexif/exif-entry.c
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+++ b/libexif/exif-entry.c
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@@ -1371,8 +1371,8 @@ exif_entry_get_value (ExifEntry *e, char *val, unsigned int maxlen)
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{
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unsigned char *utf16;
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- /* Sanity check the size to prevent overflow */
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- if (e->size+sizeof(uint16_t)+1 < e->size) break;
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+ /* Sanity check the size to prevent overflow. Note EXIF files are 64kb at most. */
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+ if (e->size >= 65536 - sizeof(uint16_t)*2) break;
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/* The tag may not be U+0000-terminated , so make a local
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U+0000-terminated copy before converting it */
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