[libvirt] [PATCH v2] qemu: Prevent crash of libvirtd without guest agent configuration

2013-07-16 Thread Alex Jia 
If users haven't configured guest agent then qemuAgentCommand() will
dereference a NULL 'mon' pointer, which causes crash of libvirtd.

With the patch, when the qemu-ga service isn't running in the guest,
a expected error error: Guest agent is not responding: Guest agent
not available for now will be raised, and the error error: argument
unsupported: QEMU guest agent is not configured is raised when the
guest hasn't configured guest agent. 


GDB backtrace:

(gdb) bt
#0  virNetServerFatalSignal (sig=11, siginfo=value optimized out, 
context=value optimized out) at rpc/virnetserver.c:326
#1  signal handler called
#2  qemuAgentCommand (mon=0x0, cmd=0x7f39300017b0, reply=0x7f394b090910, 
seconds=-2) at qemu/qemu_agent.c:975
#3  0x7f39429507f6 in qemuAgentGetVCPUs (mon=0x0, info=0x7f394b0909b8) at 
qemu/qemu_agent.c:1475
#4  0x7f39429d9857 in qemuDomainGetVcpusFlags (dom=value optimized out, 
flags=9) at qemu/qemu_driver.c:4849
#5  0x7f3957dffd8d in virDomainGetVcpusFlags (domain=0x7f3939c0, 
flags=8) at libvirt.c:9843

How to reproduce?

# To start a guest without guest agent configuration
# then run the following cmdline

# virsh vcpucount foobar --guest
error: End of file while reading data: Input/output error
error: One or more references were leaked after disconnect from the hypervisor
error: Failed to reconnect to the hypervisor

RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=984821

Signed-off-by: Alex Jia a...@redhat.com
---
 src/qemu/qemu_driver.c |   26 ++
 1 files changed, 26 insertions(+), 0 deletions(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 495867a..699388c 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -4122,6 +4122,19 @@ qemuDomainSetVcpusFlags(virDomainPtr dom, unsigned int 
nvcpus,
 goto endjob;
 }
 
+if (priv-agentError) {
+virReportError(VIR_ERR_AGENT_UNRESPONSIVE, %s,
+   _(QEMU guest agent is not 
+ available due to an error));
+goto cleanup;
+}
+
+if (!priv-agent) {
+virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, %s,
+   _(QEMU guest agent is not configured));
+goto cleanup;
+}
+
 qemuDomainObjEnterAgent(vm);
 ncpuinfo = qemuAgentGetVCPUs(priv-agent, cpuinfo);
 qemuDomainObjExitAgent(vm);
@@ -4839,6 +4852,19 @@ qemuDomainGetVcpusFlags(virDomainPtr dom, unsigned int 
flags)
 if (qemuDomainObjBeginJob(driver, vm, QEMU_JOB_QUERY)  0)
 goto cleanup;
 
+if (priv-agentError) {
+virReportError(VIR_ERR_AGENT_UNRESPONSIVE, %s,
+   _(QEMU guest agent is not 
+ available due to an error));
+goto cleanup;
+}
+
+if (!priv-agent) {
+virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, %s,
+   _(QEMU guest agent is not configured));
+goto cleanup;
+}
+
 if (!virDomainObjIsActive(vm)) {
 virReportError(VIR_ERR_OPERATION_INVALID, %s,
_(domain is not running));
-- 
1.7.1

--
libvir-list mailing list
libvir-list@redhat.com
https://www.redhat.com/mailman/listinfo/libvir-list

Re: [libvirt] [PATCH v2] qemu: Prevent crash of libvirtd without guest agent configuration

2013-07-16 Thread Peter Krempa 

On 07/16/13 11:30, Alex Jia wrote:

If users haven't configured guest agent then qemuAgentCommand() will
dereference a NULL 'mon' pointer, which causes crash of libvirtd.

With the patch, when the qemu-ga service isn't running in the guest,
a expected error error: Guest agent is not responding: Guest agent
not available for now will be raised, and the error error: argument
unsupported: QEMU guest agent is not configured is raised when the
guest hasn't configured guest agent.


GDB backtrace:

(gdb) bt
#0  virNetServerFatalSignal (sig=11, siginfo=value optimized out, context=value 
optimized out) at rpc/virnetserver.c:326
#1  signal handler called
#2  qemuAgentCommand (mon=0x0, cmd=0x7f39300017b0, reply=0x7f394b090910, 
seconds=-2) at qemu/qemu_agent.c:975
#3  0x7f39429507f6 in qemuAgentGetVCPUs (mon=0x0, info=0x7f394b0909b8) at 
qemu/qemu_agent.c:1475
#4  0x7f39429d9857 in qemuDomainGetVcpusFlags (dom=value optimized out, 
flags=9) at qemu/qemu_driver.c:4849
#5  0x7f3957dffd8d in virDomainGetVcpusFlags (domain=0x7f3939c0, 
flags=8) at libvirt.c:9843

How to reproduce?

# To start a guest without guest agent configuration
# then run the following cmdline

# virsh vcpucount foobar --guest
error: End of file while reading data: Input/output error
error: One or more references were leaked after disconnect from the hypervisor
error: Failed to reconnect to the hypervisor

RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=984821

Signed-off-by: Alex Jia a...@redhat.com
---
  src/qemu/qemu_driver.c |   26 ++
  1 files changed, 26 insertions(+), 0 deletions(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 495867a..699388c 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -4122,6 +4122,19 @@ qemuDomainSetVcpusFlags(virDomainPtr dom, unsigned int 
nvcpus,
  goto endjob;
  }

+if (priv-agentError) {
+virReportError(VIR_ERR_AGENT_UNRESPONSIVE, %s,
+   _(QEMU guest agent is not 
+ available due to an error));
+goto cleanup;


this needs to be goto endjob


+}
+
+if (!priv-agent) {
+virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, %s,
+   _(QEMU guest agent is not configured));
+goto cleanup;


here too.


+}
+
  qemuDomainObjEnterAgent(vm);
  ncpuinfo = qemuAgentGetVCPUs(priv-agent, cpuinfo);
  qemuDomainObjExitAgent(vm);
@@ -4839,6 +4852,19 @@ qemuDomainGetVcpusFlags(virDomainPtr dom, unsigned int 
flags)
  if (qemuDomainObjBeginJob(driver, vm, QEMU_JOB_QUERY)  0)
  goto cleanup;

+if (priv-agentError) {
+virReportError(VIR_ERR_AGENT_UNRESPONSIVE, %s,
+   _(QEMU guest agent is not 
+ available due to an error));
+goto cleanup;
+}
+
+if (!priv-agent) {
+virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, %s,
+   _(QEMU guest agent is not configured));
+goto cleanup;
+}
+
  if (!virDomainObjIsActive(vm)) {
  virReportError(VIR_ERR_OPERATION_INVALID, %s,
 _(domain is not running));



and also both here.

ACK with that changed.

Peter

--
libvir-list mailing list
libvir-list@redhat.com
https://www.redhat.com/mailman/listinfo/libvir-list

Re: [libvirt] [PATCH v2] qemu: Prevent crash of libvirtd without guest agent configuration

2013-07-16 Thread Peter Krempa 

On 07/16/13 13:42, Peter Krempa wrote:

On 07/16/13 11:30, Alex Jia wrote:

If users haven't configured guest agent then qemuAgentCommand() will
dereference a NULL 'mon' pointer, which causes crash of libvirtd.

With the patch, when the qemu-ga service isn't running in the guest,
a expected error error: Guest agent is not responding: Guest agent
not available for now will be raised, and the error error: argument
unsupported: QEMU guest agent is not configured is raised when the
guest hasn't configured guest agent.


GDB backtrace:

(gdb) bt
#0  virNetServerFatalSignal (sig=11, siginfo=value optimized out,
context=value optimized out) at rpc/virnetserver.c:326
#1  signal handler called
#2  qemuAgentCommand (mon=0x0, cmd=0x7f39300017b0,
reply=0x7f394b090910, seconds=-2) at qemu/qemu_agent.c:975
#3  0x7f39429507f6 in qemuAgentGetVCPUs (mon=0x0,
info=0x7f394b0909b8) at qemu/qemu_agent.c:1475
#4  0x7f39429d9857 in qemuDomainGetVcpusFlags (dom=value
optimized out, flags=9) at qemu/qemu_driver.c:4849
#5  0x7f3957dffd8d in virDomainGetVcpusFlags
(domain=0x7f3939c0, flags=8) at libvirt.c:9843

How to reproduce?

# To start a guest without guest agent configuration
# then run the following cmdline

# virsh vcpucount foobar --guest
error: End of file while reading data: Input/output error
error: One or more references were leaked after disconnect from the
hypervisor
error: Failed to reconnect to the hypervisor

RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=984821

Signed-off-by: Alex Jia a...@redhat.com
---
  src/qemu/qemu_driver.c |   26 ++
  1 files changed, 26 insertions(+), 0 deletions(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 495867a..699388c 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -4122,6 +4122,19 @@ qemuDomainSetVcpusFlags(virDomainPtr dom,
unsigned int nvcpus,
  goto endjob;
  }

+if (priv-agentError) {
+virReportError(VIR_ERR_AGENT_UNRESPONSIVE, %s,
+   _(QEMU guest agent is not 
+ available due to an error));
+goto cleanup;


this needs to be goto endjob


+}
+
+if (!priv-agent) {
+virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, %s,
+   _(QEMU guest agent is not configured));
+goto cleanup;


here too.


+}
+
  qemuDomainObjEnterAgent(vm);
  ncpuinfo = qemuAgentGetVCPUs(priv-agent, cpuinfo);
  qemuDomainObjExitAgent(vm);
@@ -4839,6 +4852,19 @@ qemuDomainGetVcpusFlags(virDomainPtr dom,
unsigned int flags)
  if (qemuDomainObjBeginJob(driver, vm, QEMU_JOB_QUERY)  0)
  goto cleanup;

+if (priv-agentError) {
+virReportError(VIR_ERR_AGENT_UNRESPONSIVE, %s,
+   _(QEMU guest agent is not 
+ available due to an error));
+goto cleanup;
+}
+
+if (!priv-agent) {
+virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, %s,
+   _(QEMU guest agent is not configured));
+goto cleanup;
+}
+
  if (!virDomainObjIsActive(vm)) {
  virReportError(VIR_ERR_OPERATION_INVALID, %s,
 _(domain is not running));



and also both here.

ACK with that changed.


I amended the commit message to be a bit more specific and changed the 
goto labels and pushed this patch. Thanks for finding this issue.




Peter



Peter

--
libvir-list mailing list
libvir-list@redhat.com
https://www.redhat.com/mailman/listinfo/libvir-list