Re: exif int overflow patch is not applied to 5.3?

From: Date: Sun, 12 Jan 2014 03:23:13 +0000
Subject: Re: exif int overflow patch is not applied to 5.3?
References: 1  Groups: php.internals 
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Hi all,

On Sun, Jan 12, 2014 at 8:17 AM, Yasuo Ohgaki <yohgaki@ohgaki.net> wrote:

> Hi all,
>
> 5.4.24/5.5.8 have this patch
>
> diff --git a/ext/exif/exif.c b/ext/exif/exif.c
> index 2fe54f7..c531d8d 100644
> --- a/ext/exif/exif.c
> +++ b/ext/exif/exif.c
> @@ -2852,7 +2852,12 @@ static int exif_process_IFD_TAG(image_info_type
> *ImageInfo, char *dir_entry, cha
>                 offset_val = php_ifd_get32u(dir_entry+8,
> ImageInfo->motorola_intel);
>                 /* If its bigger than 4 bytes, the dir entry contains an
> offset. */
>                 value_ptr = offset_base+offset_val;
> -               if (byte_count > IFDlength || offset_val >
> IFDlength-byte_count || value_ptr < dir_entry) {
> +        /*
> +            dir_entry is ImageInfo->file.list[sn].data+2+i*12
> +            offset_base is ImageInfo->file.list[sn].data-dir_offset
> +            dir_entry - offset_base is dir_offset+2+i*12
> +        */
> +               if (byte_count > IFDlength || offset_val >
> IFDlength-byte_count || value_ptr < dir_entry || offset_val <
> (size_t)(dir_entry-offset_base))
>                         /* It is important to check for IMAGE_FILETYPE_TIFF
>                          * JPEG does not use absolute pointers instead its
> pointers are
>                          * relative to the start of the TIFF header in
> APP1 section. */
>
>
> https://bugs.php.net/bug.php?id=65873
>
> Is this applicable to 5.3, isn't this?
> I don't understand details of this patch, but it sounds this
> is required fix for 5.3.
>
> Could anyone give clarification?
>
> Thank you.
>

It seems this has been fixed as CVE 2011-4566 partially.

http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2011-4566

I suppose this is fix for the fix.
Any comments?

Regards,

--
Yasuo Ohgaki
yohgaki@ohgaki.net


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