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* [Qemu-devel] [PATCH] block: vhdx - fix reading beyond pointer during image creation
@ 2014-09-16 19:12 Jeff Cody
  2014-09-17  6:33 ` Markus Armbruster
  2014-09-19  9:45 ` Stefan Hajnoczi
  0 siblings, 2 replies; 6+ messages in thread
From: Jeff Cody @ 2014-09-16 19:12 UTC (permalink / raw)
  To: qemu-devel; +Cc: kwolf, stefanha

In vhdx_create_metadata(), we allocate 40 bytes to entry_buffer for
the various metadata table entries.  However, we write out 64kB from
that buffer into the new file.  Only write out the correct 40 bytes.

Signed-off-by: Jeff Cody <jcody@redhat.com>
---
 block/vhdx.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/block/vhdx.c b/block/vhdx.c
index 796b7bd..b52ec32 100644
--- a/block/vhdx.c
+++ b/block/vhdx.c
@@ -1407,6 +1407,12 @@ exit:
     return ret;
 }
 
+#define VHDX_METADATA_ENTRY_BUFFER_SIZE \
+                                    (sizeof(VHDXFileParameters)               +\
+                                     sizeof(VHDXVirtualDiskSize)              +\
+                                     sizeof(VHDXPage83Data)                   +\
+                                     sizeof(VHDXVirtualDiskLogicalSectorSize) +\
+                                     sizeof(VHDXVirtualDiskPhysicalSectorSize))
 
 /*
  * Create the Metadata entries.
@@ -1445,11 +1451,7 @@ static int vhdx_create_new_metadata(BlockDriverState *bs,
     VHDXVirtualDiskLogicalSectorSize  *mt_log_sector_size;
     VHDXVirtualDiskPhysicalSectorSize *mt_phys_sector_size;
 
-    entry_buffer = g_malloc0(sizeof(VHDXFileParameters)               +
-                             sizeof(VHDXVirtualDiskSize)              +
-                             sizeof(VHDXPage83Data)                   +
-                             sizeof(VHDXVirtualDiskLogicalSectorSize) +
-                             sizeof(VHDXVirtualDiskPhysicalSectorSize));
+    entry_buffer = g_malloc0(VHDX_METADATA_ENTRY_BUFFER_SIZE);
 
     mt_file_params = entry_buffer;
     offset += sizeof(VHDXFileParameters);
@@ -1530,7 +1532,7 @@ static int vhdx_create_new_metadata(BlockDriverState *bs,
     }
 
     ret = bdrv_pwrite(bs, metadata_offset + (64 * KiB), entry_buffer,
-                      VHDX_HEADER_BLOCK_SIZE);
+                      VHDX_METADATA_ENTRY_BUFFER_SIZE);
     if (ret < 0) {
         goto exit;
     }
@@ -1725,7 +1727,6 @@ static int vhdx_create_new_region_table(BlockDriverState *bs,
         goto exit;
     }
 
-
 exit:
     g_free(s);
     g_free(buffer);
@@ -1876,7 +1877,6 @@ static int vhdx_create(const char *filename, QemuOpts *opts, Error **errp)
     }
 
 
-
 delete_and_exit:
     bdrv_unref(bs);
 exit:
-- 
1.9.3

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [Qemu-devel] [PATCH] block: vhdx - fix reading beyond pointer during image creation
  2014-09-16 19:12 [Qemu-devel] [PATCH] block: vhdx - fix reading beyond pointer during image creation Jeff Cody
@ 2014-09-17  6:33 ` Markus Armbruster
  2014-09-17 19:54   ` Jeff Cody
  2014-09-19  9:45 ` Stefan Hajnoczi
  1 sibling, 1 reply; 6+ messages in thread
From: Markus Armbruster @ 2014-09-17  6:33 UTC (permalink / raw)
  To: Jeff Cody; +Cc: kwolf, qemu-devel, stefanha

Jeff Cody <jcody@redhat.com> writes:

> In vhdx_create_metadata(), we allocate 40 bytes to entry_buffer for
> the various metadata table entries.  However, we write out 64kB from
> that buffer into the new file.  Only write out the correct 40 bytes.
>
> Signed-off-by: Jeff Cody <jcody@redhat.com>
> ---
>  block/vhdx.c | 16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/block/vhdx.c b/block/vhdx.c
> index 796b7bd..b52ec32 100644
> --- a/block/vhdx.c
> +++ b/block/vhdx.c
> @@ -1407,6 +1407,12 @@ exit:
>      return ret;
>  }
>  
> +#define VHDX_METADATA_ENTRY_BUFFER_SIZE \
> +                                    (sizeof(VHDXFileParameters)               +\
> +                                     sizeof(VHDXVirtualDiskSize)              +\
> +                                     sizeof(VHDXPage83Data)                   +\
> +                                     sizeof(VHDXVirtualDiskLogicalSectorSize) +\
> +                                     sizeof(VHDXVirtualDiskPhysicalSectorSize))

Long lines, caused by excessive indentation.  Emacs suggests

#define VHDX_METADATA_ENTRY_BUFFER_SIZE         \
    (sizeof(VHDXFileParameters)               + \
     sizeof(VHDXVirtualDiskSize)              + \
     sizeof(VHDXPage83Data)                   + \
     sizeof(VHDXVirtualDiskLogicalSectorSize) + \
     sizeof(VHDXVirtualDiskPhysicalSectorSize))

>  
>  /*
>   * Create the Metadata entries.
> @@ -1445,11 +1451,7 @@ static int vhdx_create_new_metadata(BlockDriverState *bs,
>      VHDXVirtualDiskLogicalSectorSize  *mt_log_sector_size;
>      VHDXVirtualDiskPhysicalSectorSize *mt_phys_sector_size;
>  
> -    entry_buffer = g_malloc0(sizeof(VHDXFileParameters)               +
> -                             sizeof(VHDXVirtualDiskSize)              +
> -                             sizeof(VHDXPage83Data)                   +
> -                             sizeof(VHDXVirtualDiskLogicalSectorSize) +
> -                             sizeof(VHDXVirtualDiskPhysicalSectorSize));
> +    entry_buffer = g_malloc0(VHDX_METADATA_ENTRY_BUFFER_SIZE);
>  
>      mt_file_params = entry_buffer;
>      offset += sizeof(VHDXFileParameters);
> @@ -1530,7 +1532,7 @@ static int vhdx_create_new_metadata(BlockDriverState *bs,
>      }
>  
>      ret = bdrv_pwrite(bs, metadata_offset + (64 * KiB), entry_buffer,
> -                      VHDX_HEADER_BLOCK_SIZE);
> +                      VHDX_METADATA_ENTRY_BUFFER_SIZE);
>      if (ret < 0) {
>          goto exit;
>      }

Fixes read beyond end of buffer.  Crash bug when sufficiently unlucky.

> @@ -1725,7 +1727,6 @@ static int vhdx_create_new_region_table(BlockDriverState *bs,
>          goto exit;
>      }
>  
> -
>  exit:
>      g_free(s);
>      g_free(buffer);
> @@ -1876,7 +1877,6 @@ static int vhdx_create(const char *filename, QemuOpts *opts, Error **errp)
>      }
>  
>  
> -
>  delete_and_exit:
>      bdrv_unref(bs);
>  exit:

These two hunks are unrelated.  I wouldn't include them.  Advice, not
objection.

Keeping two out of three blank lines looks odd, but pairs of blank lines
occur elsewhere in the function, so I guess it's intentional.

If you clean up the long lines, you can add my R-by.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [Qemu-devel] [PATCH] block: vhdx - fix reading beyond pointer during image creation
  2014-09-17  6:33 ` Markus Armbruster
@ 2014-09-17 19:54   ` Jeff Cody
  2014-09-18  6:47     ` Markus Armbruster
  0 siblings, 1 reply; 6+ messages in thread
From: Jeff Cody @ 2014-09-17 19:54 UTC (permalink / raw)
  To: Markus Armbruster; +Cc: kwolf, qemu-devel, stefanha

On Wed, Sep 17, 2014 at 08:33:10AM +0200, Markus Armbruster wrote:
> Jeff Cody <jcody@redhat.com> writes:
> 
> > In vhdx_create_metadata(), we allocate 40 bytes to entry_buffer for
> > the various metadata table entries.  However, we write out 64kB from
> > that buffer into the new file.  Only write out the correct 40 bytes.
> >
> > Signed-off-by: Jeff Cody <jcody@redhat.com>
> > ---
> >  block/vhdx.c | 16 ++++++++--------
> >  1 file changed, 8 insertions(+), 8 deletions(-)
> >
> > diff --git a/block/vhdx.c b/block/vhdx.c
> > index 796b7bd..b52ec32 100644
> > --- a/block/vhdx.c
> > +++ b/block/vhdx.c
> > @@ -1407,6 +1407,12 @@ exit:
> >      return ret;
> >  }
> >  
> > +#define VHDX_METADATA_ENTRY_BUFFER_SIZE \
> > +                                    (sizeof(VHDXFileParameters)               +\
> > +                                     sizeof(VHDXVirtualDiskSize)              +\
> > +                                     sizeof(VHDXPage83Data)                   +\
> > +                                     sizeof(VHDXVirtualDiskLogicalSectorSize) +\
> > +                                     sizeof(VHDXVirtualDiskPhysicalSectorSize))
> 
> Long lines, caused by excessive indentation.  Emacs suggests
> 
> #define VHDX_METADATA_ENTRY_BUFFER_SIZE         \
>     (sizeof(VHDXFileParameters)               + \
>      sizeof(VHDXVirtualDiskSize)              + \
>      sizeof(VHDXPage83Data)                   + \
>      sizeof(VHDXVirtualDiskLogicalSectorSize) + \
>      sizeof(VHDXVirtualDiskPhysicalSectorSize))
> 

So, I was getting ready to respin this, but double checked the patch -
it shows the lines ending on column 80 (as intended), and
checkpatch.pl had no issue with it.  Did you accidentally (or
intentionally!) count the leading '+' of the patch itself?

> >  
> >  /*
> >   * Create the Metadata entries.
> > @@ -1445,11 +1451,7 @@ static int vhdx_create_new_metadata(BlockDriverState *bs,
> >      VHDXVirtualDiskLogicalSectorSize  *mt_log_sector_size;
> >      VHDXVirtualDiskPhysicalSectorSize *mt_phys_sector_size;
> >  
> > -    entry_buffer = g_malloc0(sizeof(VHDXFileParameters)               +
> > -                             sizeof(VHDXVirtualDiskSize)              +
> > -                             sizeof(VHDXPage83Data)                   +
> > -                             sizeof(VHDXVirtualDiskLogicalSectorSize) +
> > -                             sizeof(VHDXVirtualDiskPhysicalSectorSize));
> > +    entry_buffer = g_malloc0(VHDX_METADATA_ENTRY_BUFFER_SIZE);
> >  
> >      mt_file_params = entry_buffer;
> >      offset += sizeof(VHDXFileParameters);
> > @@ -1530,7 +1532,7 @@ static int vhdx_create_new_metadata(BlockDriverState *bs,
> >      }
> >  
> >      ret = bdrv_pwrite(bs, metadata_offset + (64 * KiB), entry_buffer,
> > -                      VHDX_HEADER_BLOCK_SIZE);
> > +                      VHDX_METADATA_ENTRY_BUFFER_SIZE);
> >      if (ret < 0) {
> >          goto exit;
> >      }
> 
> Fixes read beyond end of buffer.  Crash bug when sufficiently unlucky.
> 
> > @@ -1725,7 +1727,6 @@ static int vhdx_create_new_region_table(BlockDriverState *bs,
> >          goto exit;
> >      }
> >  
> > -
> >  exit:
> >      g_free(s);
> >      g_free(buffer);
> > @@ -1876,7 +1877,6 @@ static int vhdx_create(const char *filename, QemuOpts *opts, Error **errp)
> >      }
> >  
> >  
> > -
> >  delete_and_exit:
> >      bdrv_unref(bs);
> >  exit:
> 
> These two hunks are unrelated.  I wouldn't include them.  Advice, not
> objection.
> 
> Keeping two out of three blank lines looks odd, but pairs of blank lines
> occur elsewhere in the function, so I guess it's intentional.
> 
> If you clean up the long lines, you can add my R-by.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [Qemu-devel] [PATCH] block: vhdx - fix reading beyond pointer during image creation
  2014-09-17 19:54   ` Jeff Cody
@ 2014-09-18  6:47     ` Markus Armbruster
  2014-09-18  7:43       ` Markus Armbruster
  0 siblings, 1 reply; 6+ messages in thread
From: Markus Armbruster @ 2014-09-18  6:47 UTC (permalink / raw)
  To: Jeff Cody; +Cc: kwolf, qemu-devel, stefanha

Jeff Cody <jcody@redhat.com> writes:

> On Wed, Sep 17, 2014 at 08:33:10AM +0200, Markus Armbruster wrote:
>> Jeff Cody <jcody@redhat.com> writes:
>> 
>> > In vhdx_create_metadata(), we allocate 40 bytes to entry_buffer for
>> > the various metadata table entries.  However, we write out 64kB from
>> > that buffer into the new file.  Only write out the correct 40 bytes.
>> >
>> > Signed-off-by: Jeff Cody <jcody@redhat.com>
>> > ---
>> >  block/vhdx.c | 16 ++++++++--------
>> >  1 file changed, 8 insertions(+), 8 deletions(-)
>> >
>> > diff --git a/block/vhdx.c b/block/vhdx.c
>> > index 796b7bd..b52ec32 100644
>> > --- a/block/vhdx.c
>> > +++ b/block/vhdx.c
>> > @@ -1407,6 +1407,12 @@ exit:
>> >      return ret;
>> >  }
>> >  
>> > +#define VHDX_METADATA_ENTRY_BUFFER_SIZE \
>> > +                                    (sizeof(VHDXFileParameters)               +\
>> > +                                     sizeof(VHDXVirtualDiskSize)              +\
>> > +                                     sizeof(VHDXPage83Data)                   +\
>> > +                                     sizeof(VHDXVirtualDiskLogicalSectorSize) +\
>> > +                                     sizeof(VHDXVirtualDiskPhysicalSectorSize))
>> 
>> Long lines, caused by excessive indentation.  Emacs suggests
>> 
>> #define VHDX_METADATA_ENTRY_BUFFER_SIZE         \
>>     (sizeof(VHDXFileParameters)               + \
>>      sizeof(VHDXVirtualDiskSize)              + \
>>      sizeof(VHDXPage83Data)                   + \
>>      sizeof(VHDXVirtualDiskLogicalSectorSize) + \
>>      sizeof(VHDXVirtualDiskPhysicalSectorSize))
>> 
>
> So, I was getting ready to respin this, but double checked the patch -
> it shows the lines ending on column 80 (as intended), and
> checkpatch.pl had no issue with it.  Did you accidentally (or
> intentionally!) count the leading '+' of the patch itself?

I didn't count anything, I trusted my eyes, which screamed "ugly!" :)

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [Qemu-devel] [PATCH] block: vhdx - fix reading beyond pointer during image creation
  2014-09-18  6:47     ` Markus Armbruster
@ 2014-09-18  7:43       ` Markus Armbruster
  0 siblings, 0 replies; 6+ messages in thread
From: Markus Armbruster @ 2014-09-18  7:43 UTC (permalink / raw)
  To: Jeff Cody; +Cc: kwolf, qemu-devel, stefanha

Markus Armbruster <armbru@redhat.com> writes:

> Jeff Cody <jcody@redhat.com> writes:
>
>> On Wed, Sep 17, 2014 at 08:33:10AM +0200, Markus Armbruster wrote:
>>> Jeff Cody <jcody@redhat.com> writes:
>>> 
>>> > In vhdx_create_metadata(), we allocate 40 bytes to entry_buffer for
>>> > the various metadata table entries.  However, we write out 64kB from
>>> > that buffer into the new file.  Only write out the correct 40 bytes.
>>> >
>>> > Signed-off-by: Jeff Cody <jcody@redhat.com>
>>> > ---
>>> >  block/vhdx.c | 16 ++++++++--------
>>> >  1 file changed, 8 insertions(+), 8 deletions(-)
>>> >
>>> > diff --git a/block/vhdx.c b/block/vhdx.c
>>> > index 796b7bd..b52ec32 100644
>>> > --- a/block/vhdx.c
>>> > +++ b/block/vhdx.c
>>> > @@ -1407,6 +1407,12 @@ exit:
>>> >      return ret;
>>> >  }
>>> >  
>>> > +#define VHDX_METADATA_ENTRY_BUFFER_SIZE \
>>> > +                                    (sizeof(VHDXFileParameters)               +\
>>> > +                                     sizeof(VHDXVirtualDiskSize)              +\
>>> > +                                     sizeof(VHDXPage83Data)                   +\
>>> > +                                     sizeof(VHDXVirtualDiskLogicalSectorSize) +\
>>> > +                                     sizeof(VHDXVirtualDiskPhysicalSectorSize))
>>> 
>>> Long lines, caused by excessive indentation.  Emacs suggests
>>> 
>>> #define VHDX_METADATA_ENTRY_BUFFER_SIZE         \
>>>     (sizeof(VHDXFileParameters)               + \
>>>      sizeof(VHDXVirtualDiskSize)              + \
>>>      sizeof(VHDXPage83Data)                   + \
>>>      sizeof(VHDXVirtualDiskLogicalSectorSize) + \
>>>      sizeof(VHDXVirtualDiskPhysicalSectorSize))
>>> 
>>
>> So, I was getting ready to respin this, but double checked the patch -
>> it shows the lines ending on column 80 (as intended), and
>> checkpatch.pl had no issue with it.  Did you accidentally (or
>> intentionally!) count the leading '+' of the patch itself?
>
> I didn't count anything, I trusted my eyes, which screamed "ugly!" :)

Forgot to say: since checkpatch is happy, I guess this is a technically
a matter of taste, so

Reviewed-by: Markus Armbruster <armbru@redhat.com>

Just in case you actually *like* hanging your code right off the right
margin of the window.  *Shudder*  ;-P

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [Qemu-devel] [PATCH] block: vhdx - fix reading beyond pointer during image creation
  2014-09-16 19:12 [Qemu-devel] [PATCH] block: vhdx - fix reading beyond pointer during image creation Jeff Cody
  2014-09-17  6:33 ` Markus Armbruster
@ 2014-09-19  9:45 ` Stefan Hajnoczi
  1 sibling, 0 replies; 6+ messages in thread
From: Stefan Hajnoczi @ 2014-09-19  9:45 UTC (permalink / raw)
  To: Jeff Cody; +Cc: kwolf, qemu-devel

[-- Attachment #1: Type: text/plain, Size: 519 bytes --]

On Tue, Sep 16, 2014 at 03:12:06PM -0400, Jeff Cody wrote:
> In vhdx_create_metadata(), we allocate 40 bytes to entry_buffer for
> the various metadata table entries.  However, we write out 64kB from
> that buffer into the new file.  Only write out the correct 40 bytes.
> 
> Signed-off-by: Jeff Cody <jcody@redhat.com>
> ---
>  block/vhdx.c | 16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)

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

Stefan

[-- Attachment #2: Type: application/pgp-signature, Size: 473 bytes --]

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2014-09-19  9:45 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-09-16 19:12 [Qemu-devel] [PATCH] block: vhdx - fix reading beyond pointer during image creation Jeff Cody
2014-09-17  6:33 ` Markus Armbruster
2014-09-17 19:54   ` Jeff Cody
2014-09-18  6:47     ` Markus Armbruster
2014-09-18  7:43       ` Markus Armbruster
2014-09-19  9:45 ` Stefan Hajnoczi

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