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  1. 07 2月, 2015 5 次提交
  3. 24 1月, 2015 1 次提交
    • J
      block: update string sizes for filename,backing_file,exact_filename · 9a29e18f
      由 Jeff Cody 提交于 
      The string field entries 'filename', 'backing_file', and
'exact_filename' in the BlockDriverState struct are defined as 1024
bytes.

However, many places that use these values accept a maximum of PATH_MAX
bytes, so we have a mixture of 1024 byte and PATH_MAX byte allocations.
This patch makes the BlockDriverStruct field string sizes match usage.

This patch also does a few fixes related to the size that needs to
happen now:

    * the block qapi driver is updated to use PATH_MAX bytes
    * the qcow and qcow2 drivers have an additional safety check
    * the block vvfat driver is updated to use PATH_MAX bytes
      for the size of backing_file, for systems where PATH_MAX is < 1024
      bytes.
    * qemu-img uses PATH_MAX rather than 1024.  These instances were not
      changed to be dynamically allocated, however, as the extra
      temporary 3K in stack usage for qemu-img does not seem worrisome.
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Signed-off-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      9a29e18f
  5. 14 1月, 2015 1 次提交
  7. 13 1月, 2015 5 次提交
  9. 13 12月, 2014 1 次提交
  11. 12 12月, 2014 1 次提交
    • M
      vmdk: Fix error for JSON descriptor file names · 5c98415b
      由 Max Reitz 提交于 
      If vmdk blindly tries to use path_combine() using bs->file->filename as
the base file name, this will result in a bad error message for JSON
file names when calling bdrv_open(). It is better to only try
bs->file->exact_filename; if that is empty, bs->file->filename will be
useless for path_combine() and an error should be emitted (containing
bs->file->filename because desc_file_path (which is
bs->file->exact_filename) is empty).
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Message-id: 1417615043-26174-2-git-send-email-mreitz@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
      5c98415b
  13. 10 12月, 2014 6 次提交
    • M
      block: Make essential BlockDriver objects public · 5f535a94
      由 Max Reitz 提交于 
      There are some block drivers which are essential to QEMU and may not be
removed: These are raw, file and qcow2 (as the default non-raw format).
Make their BlockDriver objects public so they can be directly referenced
throughout the block layer without needing to call bdrv_find_format()
and having to deal with an error at runtime, while the real problem
occurred during linking (where raw, file or qcow2 were not linked into
qemu).

Cc: qemu-stable@nongnu.org
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      5f535a94
    • K
      raw: Prohibit dangerous writes for probed images · 38f3ef57
      由 Kevin Wolf 提交于 
      If the user neglects to specify the image format, QEMU probes the
image to guess it automatically, for convenience.

Relying on format probing is insecure for raw images (CVE-2008-2004).
If the guest writes a suitable header to the device, the next probe
will recognize a format chosen by the guest.  A malicious guest can
abuse this to gain access to host files, e.g. by crafting a QCOW2
header with backing file /etc/shadow.

Commit 1e72d3b7 (April 2008) provided -drive parameter format to let
users disable probing.  Commit f965509c (March 2009) extended QCOW2 to
optionally store the backing file format, to let users disable backing
file probing.  QED has had a flag to suppress probing since the
beginning (2010), set whenever a raw backing file is assigned.

All of these additions that allow to avoid format probing have to be
specified explicitly. The default still allows the attack.

In order to fix this, commit 79368c81 (July 2010) put probed raw images
in a restricted mode, in which they wouldn't be able to overwrite the
first few bytes of the image so that they would identify as a different
image. If a write to the first sector would write one of the signatures
of another driver, qemu would instead zero out the first four bytes.
This patch was later reverted in commit 8b33d9ee (September 2010) because
it didn't get the handling of unaligned qiov members right.

Today's block layer that is based on coroutines and has qiov utility
functions makes it much easier to get this functionality right, so this
patch implements it.

The other differences of this patch to the old one are that it doesn't
silently write something different than the guest requested by zeroing
out some bytes (it fails the request instead) and that it doesn't
maintain a list of signatures in the raw driver (it calls the usual
probe function instead).

Note that this change doesn't introduce new breakage for false positive
cases where the guest legitimately writes data into the first sector
that matches the signatures of an image format (e.g. for nested virt):
These cases were broken before, only the failure mode changes from
corruption after the next restart (when the wrong format is probed) to
failing the problematic write request.

Also note that like in the original patch, the restrictions only apply
if the image format has been guessed by probing. Explicitly specifying a
format allows guests to write anything they like.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 1416497234-29880-8-git-send-email-kwolf@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      38f3ef57
    • K
      block: Read only one sector for format probing · 7cddd372
      由 Kevin Wolf 提交于 
      The only image format driver that even potentially accesses anything
after 512 bytes in its bdrv_probe() implementation is VMDK, which reads
a plain-text descriptor file. In practice, the field it's looking for
seems to come first and will be well within the first 512 bytes, too.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Message-id: 1416497234-29880-7-git-send-email-kwolf@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      7cddd372
    • M
      nbd: Change external interface to BlockBackend · e140177d
      由 Max Reitz 提交于 
      Substitute BlockDriverState by BlockBackend in every globally visible
function provided by nbd.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Message-id: 1416309679-333-5-git-send-email-mreitz@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      e140177d
    • F
      block: Add bdrv_get_node_name · 20a9e77d
      由 Fam Zheng 提交于 
      This returns the node name of a BDS. Remove the TODO comment and expect
the callers to be explicit.
Signed-off-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      20a9e77d
    • F
      block: Add bdrv_next_node · 04df765a
      由 Fam Zheng 提交于 
      Similar to bdrv_next, this traverses through graph_bdrv_states. Will be
useful to enumerate all the named nodes.
Signed-off-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      04df765a
  15. 11 11月, 2014 1 次提交
  17. 03 11月, 2014 7 次提交
  19. 23 10月, 2014 1 次提交
  21. 20 10月, 2014 9 次提交
  23. 22 9月, 2014 2 次提交