[libvirt] [PATCH 2/6] virDomainFormatSchedDef: Handle case when func returns NULL
As unlikely as it might seem, func passed to this function can
return NULL. And in some cases it indeed does so:
virDomainDefGetVcpuSched and virDomainDefGetIOThreadSched.
However, the function I'm fixing blindly dereference value func
returned thus leading to SIGSEGV.
conf/domain_conf.c: In function 'virDomainDefFormatInternal':
conf/domain_conf.c:22155:22: error: potential null pointer dereference
[-Werror=null-dereference]
if (sched->policy == i)
~~~~~^~~~~~~~
conf/domain_conf.c:22184:26: error: potential null pointer dereference
[-Werror=null-dereference]
priority = sched->priority;
~~~~~~~~~^~~~~~~~~~~~~~~~~
conf/domain_conf.c:22190:30: error: potential null pointer dereference
[-Werror=null-dereference]
if (sched->priority == priority)
~~~~~^~~~~~~~~~
conf/domain_conf.c:22155:22: error: potential null pointer dereference
[-Werror=null-dereference]
if (sched->policy == i)
~~~~~^~~~~~~~
conf/domain_conf.c:22184:26: error: potential null pointer dereference
[-Werror=null-dereference]
priority = sched->priority;
~~~~~~~~~^~~~~~~~~~~~~~~~~
conf/domain_conf.c:22190:30: error: potential null pointer dereference
[-Werror=null-dereference]
if (sched->priority == priority)
~~~~~^~~~~~~~~~
Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com>
---
src/conf/domain_conf.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 568c699..3daeb1e 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -22152,7 +22152,7 @@ virDomainFormatSchedDef(virDomainDefPtr def,
while ((next = virBitmapNextSetBit(resourceMap, next)) > -1) {
sched = func(def, next);
- if (sched->policy == i)
+ if (sched && sched->policy == i)
ignore_value(virBitmapSetBit(schedMap, next));
}
@@ -22180,14 +22180,17 @@ virDomainFormatSchedDef(virDomainDefPtr def,
/* we need to find a subset of vCPUs with the given scheduler
* that share the priority */
nextprio = virBitmapNextSetBit(schedMap, -1);
- sched = func(def, nextprio);
+
+ if (!(sched = func(def, nextprio)))
+ goto cleanup;
+
priority = sched->priority;
ignore_value(virBitmapSetBit(prioMap, nextprio));
while ((nextprio = virBitmapNextSetBit(schedMap, nextprio)) > -1) {
sched = func(def, nextprio);
- if (sched->priority == priority)
+ if (sched && sched->priority == priority)
ignore_value(virBitmapSetBit(prioMap, nextprio));
}
--
2.8.3