[libvirt] [PATCH v2 0/8] Don't hold both monitor and agent jobs at the same time

[Jonathon Jongsma]

We have to assume that the guest agent may be malicious, so we don't want to
allow any agent queries to block any other libvirt API. By holding a monitor
job and an agent job while we're querying the agent, any other threads will be
blocked from using the monitor while the agent is unresponsive. Because libvirt
waits forever for an agent response, this makes us vulnerable to a denial of
service from a malicious (or simply buggy) guest agent.

Most of the patches in the first series were already reviewed and pushed, but a
couple remain: the filesystem info functions. The problem with these functions
is that the agent functions access the vm definition (owned by the domain). If
a monitor job is not held while this is done, the vm definition could change
while we are looking up the disk alias, leading to a potentional crash.

This series tries to fix this by moving the disk alias searching up a level
from qemu_agent.c to qemu_driver.c. The code in qemu_agent.c will only return
the raw data returned from the agent command response. After the agent response
is returned and the agent job is ended, we can then look up the disk alias from
the vm definition while the domain object is locked.

In addition, a few nearby cleanups are included in this series, notably
changing to glib allocation API in a couple of places.

Jonathon Jongsma (8):
  qemu: rename qemuAgentGetFSInfoInternalDisk()
  qemu: store complete agent filesystem information
  qemu: Don't store disk alias in qemuAgentDiskInfo
  qemu: don't access vmdef within qemu_agent.c
  qemu: remove qemuDomainObjBegin/EndJobWithAgent()
  qemu: use glib alloc in qemuAgentGetFSInfoFillDisks()
  qemu: use glib allocation apis for qemuAgentFSInfo
  Use glib alloc API for virDomainFSInfo

 src/libvirt-domain.c                |  12 +-
 src/qemu/THREADS.txt                |  58 +-----
 src/qemu/qemu_agent.c               | 268 ++++------------------------
 src/qemu/qemu_agent.h               |  33 +++-
 src/qemu/qemu_domain.c              |  56 +-----
 src/qemu/qemu_domain.h              |   7 -
 src/qemu/qemu_driver.c              | 246 +++++++++++++++++++++++--
 src/remote/remote_daemon_dispatch.c |   2 +-
 tests/qemuagenttest.c               | 196 ++++----------------
 9 files changed, 336 insertions(+), 542 deletions(-)

-- 
2.21.0