Re: [Qemu-devel] [PATCH v4 00/21] block: Handle failure for potentially large allocations

[Stefan Hajnoczi]

On Thu, Jun 05, 2014 at 03:36:12PM +0200, Kevin Wolf wrote:
> A not too small part of the recent CVEs were DoS scenarios by letting
> qemu abort with too large memory allocations. We generally "fixed" these
> cases by setting some limits on values read from image files that
> influence the size of allocations.
> 
> Because we still need to allow reading large images, this works only to
> a certain degree and we still can get fairly large allocations, which
> are not unthinkable to fail on some machines.
> 
> This series converts potentially large allocations to g_try_malloc() and
> friends and handles failure gracefully e.g. by returning -ENOMEM. This
> may cause hot-plug of a new disk or individual requests to fail, but the
> VM as a whole can keep running.
> 
> v4:
> - Patch 11 (qcow2): Fix memory leak in qcow2_cache_create() [Benoît]
> 
> v3:
> - Changed qemu_try_blockalign() to only return NULL on failure. size = 0
>   results in a small allocation now (size of the alignment) [Benoît]
> - Patch 8 (nfs): Check for size != 0 before failing [Benoît]
> - Patch 11 (qcow2):
>   * Fix memory leak in alloc_refcount_block() [Max]
>   * Report internal error for -ENOMEM in qcow2_check() [Max]
> - Patch 15 (rbd): Build fix [Markus]
> 
> v2:
> - Some more places check for size = 0 before they treat NULL as an error
> - Patch 2 (block.c): Added missing NULL return check for
>   qemu_try_blockalign() [Stefan]
> - Patch 7 (iscsi): Fixed acb->task memory leak [Stefan]
> - For conversions from g_malloc() to qemu_try_blockalign(), made sure to
>   be consistent about pairing the latter with qemu_vfree() [Stefan]
> 
> *** BLURB HERE ***
> 
> Kevin Wolf (20):
>   block: Introduce qemu_try_blockalign()
>   block: Handle failure for potentially large allocations
>   bochs: Handle failure for potentially large allocations
>   cloop: Handle failure for potentially large allocations
>   curl: Handle failure for potentially large allocations
>   dmg: Handle failure for potentially large allocations
>   iscsi: Handle failure for potentially large allocations
>   nfs: Handle failure for potentially large allocations
>   parallels: Handle failure for potentially large allocations
>   qcow1: Handle failure for potentially large allocations
>   qcow2: Handle failure for potentially large allocations
>   qed: Handle failure for potentially large allocations
>   raw-posix: Handle failure for potentially large allocations
>   raw-win32: Handle failure for potentially large allocations
>   rbd: Handle failure for potentially large allocations
>   vdi: Handle failure for potentially large allocations
>   vhdx: Handle failure for potentially large allocations
>   vmdk: Handle failure for potentially large allocations
>   vpc: Handle failure for potentially large allocations
>   mirror: Handle failure for potentially large allocations
> 
> Max Reitz (1):
>   qcow2: Return useful error code in refcount_init()
> 
>  block.c                | 47 ++++++++++++++++++++++++++++++++++++-------
>  block/bochs.c          |  6 +++++-
>  block/cloop.c          | 23 ++++++++++++++++++---
>  block/curl.c           |  8 +++++++-
>  block/dmg.c            | 19 ++++++++++++------
>  block/iscsi.c          | 17 +++++++++++++---
>  block/mirror.c         |  7 ++++++-
>  block/nfs.c            |  6 +++++-
>  block/parallels.c      |  6 +++++-
>  block/qcow.c           | 33 +++++++++++++++++++++++-------
>  block/qcow2-cache.c    | 13 +++++++++++-
>  block/qcow2-cluster.c  | 35 ++++++++++++++++++++++++--------
>  block/qcow2-refcount.c | 54 
> +++++++++++++++++++++++++++++++++++++++-----------
>  block/qcow2-snapshot.c | 22 +++++++++++++++-----
>  block/qcow2.c          | 41 ++++++++++++++++++++++++++++++--------
>  block/qed-check.c      |  7 +++++--
>  block/qed.c            |  6 +++++-
>  block/raw-posix.c      |  6 +++++-
>  block/rbd.c            |  7 +++++--
>  block/vdi.c            | 24 +++++++++++++++++-----
>  block/vhdx-log.c       |  6 +++++-
>  block/vhdx.c           | 12 +++++++++--
>  block/vmdk.c           | 12 +++++++++--
>  block/vpc.c            |  6 +++++-
>  block/win32-aio.c      |  6 +++++-
>  include/block/block.h  |  1 +
>  include/qemu/osdep.h   |  1 +
>  util/oslib-posix.c     | 16 +++++++++------
>  util/oslib-win32.c     |  9 +++++++--
>  29 files changed, 365 insertions(+), 91 deletions(-)
> 
> -- 
> 1.8.3.1
> 

Thanks, applied to my block tree:
https://github.com/stefanha/qemu/commits/block

Stefan

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