similar to: [PATCH nbdkit v2 0/2] Be careful not to leak server heap memory to the client.

On 4/23/19 10:09 AM, Richard W.M. Jones wrote: > If the plugin .pread method did not fill the buffer with data then the > contents of the heap could be leaked back to the client. To avoid > this create a thread-local data buffer which is initialized to zero > and expanded (with zeroes) as required. > > This buffer is shared between pread and pwrite which makes the code a >

We do not promise API stability for non-C languages; this is an API break as follows: instead of calling 'NBDKit.register_plugin model plugin' with a static model, you can now add .thread_model :(unit -> thread_model) to plugin or default to PARALLEL. Since all existing OCaml plugins will have already thought about thread models, they can convert their existing model into the new

In the C part of the OCaml plugin we created a ‘bytes’ [byte array] and passed it to the OCaml pread method. The plugin is supposed to overwrite the array with the returned data. However if (eg. because of a bug) the plugin does not fill the array then whatever was in the OCaml or possibly even the C heap before the allocation is returned to the client, possibly resulting in a leak of sensitive

This bug was found by Eric Blake. In the .pread method we allocate a buffer in the server and pass it to the plugin. The plugin is supposed to fill it with data. The buffer was uninitialized so initially contained random heap data, but that's OK provided the plugin fully overwrote it with data. All correctly written plugins ought to do this, however there is the possibility of an

libvirt-ocaml is used only by virt-v2v, so move it to this repository, instead of having it around in the common submodule. The removal from common will happen later. Pino Toscano (2): common: Bundle the libvirt-ocaml library for use by virt-v2v build: switch embedded copy of libvirt-ocaml .gitignore | 2 + 3rdparty/libvirt-ocaml/Makefile.am |

We noticed while writing various libnbd tests that when the delay filter is in use, there are scenarios where we had to resort to SIGKILL to get rid of nbdkit, because it was non-responsive to SIGINT. I'm still trying to figure out the best way to add testsuite coverage of this, but already proved to myself that it works from the command line, under two scenarios that both used to cause long

Hi, this is a mostly done attempt to switch to ocaml-libvirt, embedding the latest version of it from git. This way, it is possible to improve the way v2v connects to libvirt for both input, and output modules, and interacts with libvirt (e.g. no more virsh calls needed in virt-v2v). As side effect, virt-v2v now requires libvirt, as keeping it optional would create too much burden. I could not

On 4/23/19 10:09 AM, Richard W.M. Jones wrote: > In the C part of the OCaml plugin we created a ‘bytes’ [byte array] > and passed it to the OCaml pread method. The plugin is supposed to > overwrite the array with the returned data. > > However if (eg. because of a bug) the plugin does not fill the array > then whatever was in the OCaml or possibly even the C heap before the

Hi, this is a mostly done attempt to switch to ocaml-libvirt, embedding the latest version of it from git. This way, it is possible to improve the way v2v connects to libvirt for both input, and output modules, and interacts with libvirt (e.g. no more virsh calls needed in virt-v2v). As side effect, virt-v2v now requires libvirt, as keeping it optional would create too much burden. I could not

Hi, this is a mostly done attempt to switch to ocaml-libvirt, embedding the latest version of it from git. This way, it is possible to improve the way v2v connects to libvirt for both input, and output modules, and interacts with libvirt (e.g. no more virsh calls needed in virt-v2v). As side effect, virt-v2v now requires libvirt, as keeping it optional would create too much burden. I could not

Hi, this series switches virt-2v to ocaml-libvirt, embedding the latest version of it from git. This way, it is possible to improve the way v2v connects to libvirt for both input, and output modules, and interacts with libvirt (e.g. no more virsh calls needed in virt-v2v). As side effect, virt-v2v now requires libvirt, as keeping it optional would create too much burden. I could not test all

Hi, this series switches virt-2v to ocaml-libvirt, embedding the latest version of it from git. This way, it is possible to improve the way v2v connects to libvirt for both input, and output modules, and interacts with libvirt (e.g. no more virsh calls needed in virt-v2v). As side effect, virt-v2v now requires libvirt, as keeping it optional would create too much burden. I could not test all

This is a quick hack to experiment with parallel threading model in the python plugin. Changes: - Use aligned buffers to make it possible to use O_DIRECT. Using parallel I/O does not buy us much when using buffered I/O. pwrite() copies data to the page cache, and pread() reads data from the page cache. - Disable extents in the file plugin. This way we can compare it with the python

Since v1: - rework .can_cache to be tri-state, with default of no advertisement (ripple effect through other patches) - add a lot more patches in order to round out filter support And in the meantime, Rich pushed NBD_CMD_CACHE support into libnbd, so in theory we now have a way to test cache commands through the entire stack. Eric Blake (24): server: Internal hooks for implementing

This was a bit harder than sh, but still a lot of copy-and-paste. Signed-off-by: Eric Blake <eblake@redhat.com> --- Note: I'm not sure how to actually test this beyond compilation. --- plugins/ocaml/ocaml.c | 51 ++++++++++++++++++++++++++++++++++++++++ plugins/ocaml/NBDKit.ml | 16 ++++++++++++- plugins/ocaml/NBDKit.mli | 5 ++++ 3 files changed, 71 insertions(+), 1 deletion(-)

On 11/16/2017 09:13 PM, Eric Blake wrote: > We can't guarantee what storage duration the caller's request > for a thread name has; and in fact, if the caller uses > plugin_name() for their thread name, then the moment .unload > is called, our threadlocal storage is pointing to la-la-land > and we get a nice SEGV while trying to print any debug message. > So copy the

These patches should be ready to go in now; I will also post my work-in-progress for enabling full parallel handling that depends on these, but with that series, I was still getting crashes or hangs with test-socket-activation (I think I've nailed all the crashes I've seen, but the hang is rather insidious; see my other email

On 2/11/20 11:15 AM, Richard W.M. Jones wrote: > Since we're going to be calling this function a lot, add a short alias > for it. > --- > server/internal.h | 1 + > server/public.c | 6 +++--- > 2 files changed, 4 insertions(+), 3 deletions(-) > > diff --git a/server/internal.h b/server/internal.h > index a1fa7309..1e7b4cf0 100644 > --- a/server/internal.h

https://bugzilla.redhat.com/show_bug.cgi?id=1401320 This series contains two new operations. The second -- and least controversial -- is "passwd-backups" which removes files such as /etc/passwd-, /etc/shadow- and so on. The first one ("backup-files") searches the whole guest filesystem for any regular file which looks like an editor backup file, such as "*~" and

v3: - Split out test for "unix-like" guest OSes into separate commit. - Add guestfish --format=qcow2 to the test (x2). Rich.