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Possible memory leak of cgroup in Domain.SetThrottleGroup #3
Description
Possible memory leak of cgroup in Domain.SetThrottleGroup
Same problem as DelThrottleGroup: cgroup is allocated with C.CString and never
freed. Every call leaks len(group)+1 bytes.
domain.go:6093
func (d *Domain) SetThrottleGroup(group string, params *DomainBlockIoTuneParameters, flags DomainModificationImpact) error {
info := getBlockIoTuneParametersFieldInfo(params)
cparams, cnparams, gerr := typedParamsPackNew(info)
if gerr != nil {
return gerr
}
defer C.virTypedParamsFreeWrapper(cparams, cnparams)
var err C.virError
cgroup := C.CString(group)
ret := C.virDomainSetThrottleGroupWrapper(d.ptr, cgroup, cparams, cnparams, C.uint(flags), &err)
if ret == -1 {
return makeError(&err)
}
return nil
}Note the cparams on the line above is released with a defer, but cgroup is not.
libvirt takes the group name as const char * and copies it, so the caller owns the
buffer. cgroup is a local, so no other function can reach it after the return.
Fix:
cgroup := C.CString(group)
defer C.free(unsafe.Pointer(cgroup))If you could credit me as a reporter for my contributions to security advisory I will be thankful.
Activity
andreabolognani commentedon Aug 31, 2026
Development of libvirt-go-module happens on GitLab: https://gitlab.com/libvirt/libvirt-go-module
Since you seem to already have a fix prepared, you can just open a merge request for it.