The virNWFilterObjListNumOfNWFilters method iterates over the driver->nwfilters, accessing virNWFilterObj instances. As such it needs to be protected against concurrent modification of the driver->nwfilters object. This API allows unprivileged users to connect, so users with read-only access to libvirt can cause a denial of service crash if they are able to race with a call of virNWFilterUndefine. Since network filters are usually statically defined, this is considered a low severity problem. This is assigned CVE-2022-0897. Reviewed-by: Eric Blake <eblake(a)redhat.com&gt; Signed-off-by: Daniel P. Berrangé <berrange(a)redhat.com&gt; --- Pushed as a pre-reviewed patch from the security list src/nwfilter/nwfilter_driver.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/src/nwfilter/nwfilter_driver.c b/src/nwfilter/nwfilter_driver.c index 3ce8fce7f9..a493205c80 100644 --- a/src/nwfilter/nwfilter_driver.c +++ b/src/nwfilter/nwfilter_driver.c @@ -478,11 +478,15 @@ nwfilterLookupByName(virConnectPtr conn, static int nwfilterConnectNumOfNWFilters(virConnectPtr conn) { + int ret; if (virConnectNumOfNWFiltersEnsureACL(conn) < 0) return -1; - return virNWFilterObjListNumOfNWFilters(driver->nwfilters, conn, - virConnectNumOfNWFiltersCheckACL); + nwfilterDriverLock(); + ret = virNWFilterObjListNumOfNWFilters(driver->nwfilters, conn, + virConnectNumOfNWFiltersCheckACL); + nwfilterDriverUnlock(); + return ret; } -- 2.35.1