On Fri, Jan 24, 2020 at 11:27:17 +0100, Michal Privoznik wrote: > When fixing [1] I've ran attached reproducer and had it spawn > 1024 threads and query capabilities XML in each one of them. This > lead libvirtd to hit the RLIMIT_NOFILE limit which was kind of > expected. What wasn't expected was a subsequent segfault. It > happened because virCPUProbeHost failed and returned NULL. We've > taken the NULL and passed it to virCapabilitiesHostNUMARef() > which dereferenced it. Code inspection showed the same flas in > virQEMUDriverGetHostNUMACaps(), so I'm fixing both places. > > 1: https://bugzilla.redhat.com/show_bug.cgi?id=1791790 > > Signed-off-by: Michal Privoznik <mprivozn@xxxxxxxxxx> > --- > src/qemu/qemu_conf.c | 17 +++++++++++++---- > 1 file changed, 13 insertions(+), 4 deletions(-) Reviewed-by: Peter Krempa <pkrempa@xxxxxxxxxx> Consider fixing the whitespace discrepancy though: > > diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c > index b62dd1df52..8040f8ab3a 100644 > --- a/src/qemu/qemu_conf.c > +++ b/src/qemu/qemu_conf.c > @@ -1201,32 +1201,41 @@ virQEMUDriverCreateXMLConf(virQEMUDriverPtr driver, > virCapsHostNUMAPtr > virQEMUDriverGetHostNUMACaps(virQEMUDriverPtr driver) > { > + virCapsHostNUMAPtr hostnuma; > + > qemuDriverLock(driver); > > if (!driver->hostnuma) > driver->hostnuma = virCapabilitiesHostNUMANewHost(); > > + hostnuma = driver->hostnuma; > qemuDriverUnlock(driver); No newline before unlock. > > - virCapabilitiesHostNUMARef(driver->hostnuma); > + if (hostnuma) > + virCapabilitiesHostNUMARef(hostnuma); > > - return driver->hostnuma; > + return hostnuma; > } > > > virCPUDefPtr > virQEMUDriverGetHostCPU(virQEMUDriverPtr driver) > { > + virCPUDefPtr hostcpu; > + > qemuDriverLock(driver); > > if (!driver->hostcpu) > driver->hostcpu = virCPUProbeHost(virArchFromHost()); > > + hostcpu = driver->hostcpu; > + > qemuDriverUnlock(driver); Newline before unlock. > > - virCPUDefRef(driver->hostcpu); > + if (hostcpu) > + virCPUDefRef(hostcpu); > > - return driver->hostcpu; > + return hostcpu; > } > > > -- > 2.24.1 >
