[PATCH] nwfilter: fix crash when counting number of network filters
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>
Signed-off-by: Daniel P. Berrangé <berrange(a)redhat.com>
---
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