libvirt: CVE-2022-0897 missing locking in nwfilterConnectNumOfNWFilters can lead to denial of service

Source: https://gitlab.com/libvirt/libvirt
MR: 116994
Type: Security Fix
Disposition: Backport from https://gitlab.com/libvirt/libvirt/-/commit/a4947e8f63c3e6b7b067b444f3d6cf674c0d7f36
ChangeID: 628f3cc089ee965dda670aa8f9ab169cec5cb63a
Description:
        CVE-2022-0897 libvirt: missing locking in nwfilterConnectNumOfNWFilters can lead to denial of service.

Affects "libvirt < 6.1"

Signed-off-by: Hitendra Prajapati <hprajapati@mvista.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>

2 files changed, 58 insertions, 0 deletions

diff --git a/recipes-extended/libvirt/libvirt/CVE-2022-0897.patch b/recipes-extended/libvirt/libvirt/CVE-2022-0897.patch
new file mode 100644
index 00000000..81e3194c
--- /dev/null
+++ b/recipes-extended/libvirt/libvirt/CVE-2022-0897.patch
@@ -0,0 +1,57 @@
+From 949548615761737bccc0046ae30b1b7cdf50ec39 Mon Sep 17 00:00:00 2001
+From: Hitendra Prajapati <hprajapati@mvista.com>
+Date: Mon, 27 Jun 2022 11:13:53 +0530
+Subject: [PATCH] CVE-2022-0897
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Upstream-Status: Backport [https://gitlab.com/libvirt/libvirt/-/commit/a4947e8f63c3e6b7b067b444f3d6cf674c0d7f36]
+CVE: CVE-2022-0897
+Signed-off-by: Hitendra Prajapati <hprajapati@mvista.com>
+
+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's avatarEric Blake <eblake@redhat.com>
+Signed-off-by: Daniel P. Berrangé's avatarDaniel P. Berrangé <berrange@redhat.com>
+---
+ 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 1c40772..27500d1 100644
+--- a/src/nwfilter/nwfilter_driver.c
++++ b/src/nwfilter/nwfilter_driver.c
+@@ -514,11 +514,15 @@ 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;
+ }
+ 
+ 
+-- 
+2.25.1
+
diff --git a/recipes-extended/libvirt/libvirt_6.1.0.bb b/recipes-extended/libvirt/libvirt_6.1.0.bb
index d0f2c315..97c1019c 100644
--- a/recipes-extended/libvirt/libvirt_6.1.0.bb
+++ b/recipes-extended/libvirt/libvirt_6.1.0.bb
@@ -47,6 +47,7 @@ SRC_URI = "http://libvirt.org/sources/libvirt-${PV}.tar.xz;name=libvirt \
            file://CVE-2020-25637_4.patch \
            file://CVE-2021-3631.patch \
            file://CVE-2021-3667.patch \
+           file://CVE-2022-0897.patch \
           "
 SRC_URI[libvirt.md5sum] = "a870e63f20fac2ccf98e716d05256145"
 SRC_URI[libvirt.sha256sum] = "167c185be45560e73dd3e14ed375778b555c01455192de2dafc4d0f74fabebc0"