[libvirt] [PATCH] vircgroup: fix NULL pointer dereferencing

When virCgroupEnableMissingControllers fails it's possible that *group is still set to NULL. Therefore let's add a guard and an attribute for this. [#0] virCgroupRemove(group=0x0) [#1] virCgroupNewMachineSystemd [#2] virCgroupNewMachine [#3] qemuInitCgroup [#4] qemuSetupCgroup [#5] qemuProcessLaunch [#6] qemuProcessStart [#7] qemuDomainObjStart [#8] qemuDomainCreateWithFlags [#9] qemuDomainCreate ... Fixes: 1602aa28f820ada66f707cef3e536e8572fbda1e Reviewed-by: Boris Fiuczynski <fiuczy(a)linux.ibm.com&gt; Reviewed-by: Bjoern Walk <bwalk(a)linux.ibm.com&gt; Signed-off-by: Marc Hartmayer <mhartmay(a)linux.ibm.com&gt; --- src/util/vircgroup.c | 3 ++- src/util/vircgroup.h | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/src/util/vircgroup.c b/src/util/vircgroup.c index 23957c82c7fa..06e1d158febb 100644 --- a/src/util/vircgroup.c +++ b/src/util/vircgroup.c @@ -1104,7 +1104,8 @@ virCgroupNewMachineSystemd(const char *name, error: saved = virSaveLastError(); - virCgroupRemove(*group); + if (*group) + virCgroupRemove(*group); virCgroupFree(group); if (saved) { virSetError(saved); diff --git a/src/util/vircgroup.h b/src/util/vircgroup.h index 1f676f21c380..9e1ae3706b1e 100644 --- a/src/util/vircgroup.h +++ b/src/util/vircgroup.h @@ -268,7 +268,8 @@ int virCgroupGetCpusetMemoryMigrate(virCgroupPtr group, bool *migrate); int virCgroupSetCpusetCpus(virCgroupPtr group, const char *cpus); int virCgroupGetCpusetCpus(virCgroupPtr group, char **cpus); -int virCgroupRemove(virCgroupPtr group); +int virCgroupRemove(virCgroupPtr group) + ATTRIBUTE_NONNULL(1); int virCgroupKillRecursive(virCgroupPtr group, int signum); int virCgroupKillPainfully(virCgroupPtr group); -- 2.17.0