Re: [Qemu-block] [PATCH v2 0/7] Refactor DMG driver to have chunk size independence

[Ashijeet Acharya]

On Thu, Apr 27, 2017 at 1:36 PM, Ashijeet Acharya
<address@hidden> wrote:
> Previously posted series patches:
> v1: http://lists.nongnu.org/archive/html/qemu-devel/2017-04/msg04641.html
>
> This series helps to provide chunk size independence for DMG driver to prevent
> denial-of-service in cases where untrusted files are being accessed by the 
> user.
>
> This task is mentioned on the public block ToDo
> Here -> http://wiki.qemu.org/ToDo/Block/DmgChunkSizeIndependence
>
> Patch 1 introduces a new data structure to aid caching of random access points
> within a compressed stream.
>
> Patch 2 is an extension of patch 1 and introduces a new function to
> initialize/update/reset our cached random access point.
>
> Patch 3 limits the output buffer size to a max of 2MB to avoid QEMU allocate
> huge amounts of memory.
>
> Patch 4 is a simple preparatory patch to aid handling of various types of 
> chunks.
>
> Patches 5 & 6 help to handle various types of chunks.
>
> Patch 7 simply refactors dmg_co_preadv() to read multiple sectors at once.
>
> Patch 8 finally removes the error messages QEMU used to throw when an image 
> with
> chunk sizes above 64MB were accessed by the user.

John, I have squashed patch 3 and 8 (as in v1) actually and that
change is represented in patch 7 (as in v2). The cover letter here is
quite misleading, as I forgot to update it and simply did a ctrl-c --
ctrl-v carelessly.

Ashijeet

> Ashijeet Acharya (7):
>   dmg: Introduce a new struct to cache random access points
>   dmg: New function to help us cache random access point
>   dmg: Refactor and prepare dmg_read_chunk() to cache random access
>     points
>   dmg: Handle zlib compressed chunks
>   dmg: Handle bz2 compressed/raw/zeroed chunks
>   dmg: Refactor dmg_co_preadv() to start reading multiple sectors
>   dmg: Limit the output buffer size to a max of 2MB
>
>  block/dmg.c | 214 
> +++++++++++++++++++++++++++++++++++++++---------------------
>  block/dmg.h |  10 +++
>  2 files changed, 148 insertions(+), 76 deletions(-)
>
> --
> 2.6.2
>