| From 9266d14b5ca4e29b970fa03272318e5f99386e06 Mon Sep 17 00:00:00 2001 |
| From: Marcus Meissner <marcus@jet.franken.de> |
| Date: Thu, 5 Nov 2020 09:50:08 +0100 |
| Subject: [PATCH] fixed a incorrect overflow check that could be optimized |
| away. |
| |
| inspired by: |
| https://android.googlesource.com/platform/external/libexif/+/8e7345f3bc0bad06ac369d6cbc1124c8ceaf7d4b |
| |
| https://source.android.com/security/bulletin/2020-11-01 |
| |
| CVE-2020-0452 |
| |
| Downloaded from upstream commit, rebased for 0.6.22: |
| https://github.com/libexif/libexif/commit/9266d14b5ca4e29b970fa03272318e5f99386e06 |
| |
| Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de> |
| --- |
| 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 3fc0ff9..4b866ce 100644 |
| --- a/libexif/exif-entry.c |
| +++ b/libexif/exif-entry.c |
| @@ -1371,8 +1371,8 @@ exif_entry_get_value (ExifEntry *e, char *val, unsigned int maxlen) |
| { |
| unsigned char *utf16; |
| |
| - /* Sanity check the size to prevent overflow */ |
| - if (e->size+sizeof(uint16_t)+1 < e->size) break; |
| + /* Sanity check the size to prevent overflow. Note EXIF files are 64kb at most. */ |
| + if (e->size >= 65536 - sizeof(uint16_t)*2) break; |
| |
| /* The tag may not be U+0000-terminated , so make a local |
| U+0000-terminated copy before converting it */ |
