Bugzilla – Bug 1200764
VUL-0: CVE-2022-33744: xen: Arm guests can cause Dom0 DoS via PV devices (XSA-406)
Last modified: 2022-07-05 14:25:44 UTC
Xen Security Advisory CVE-2022-33744 / XSA-406
Arm guests can cause Dom0 DoS via PV devices
UPDATES IN VERSION 3
When mapping pages of guests on Arm, dom0 is using an rbtree to keep
track of the foreign mappings.
Updating of that rbtree is not always done completely with the related
lock held, resulting in a small race window, which can be used by
unprivileged guests via PV devices to cause inconsistencies of the
rbtree. These inconsistencies can lead to Denial of Service (DoS) of
dom0, e.g. by causing crashes or the inability to perform further
mappings of other guests' memory pages.
A guest performing multiple I/Os of PV devices in parallel can cause
DoS of dom0 and thus of the complete host.
Only Arm systems (32-bit and 64-bit) are vulnerable. Dom0 Linux versions
3.13 - 5.18 are vulnerable.
X86 systems are not vulnerable.
There is no mitigation available.
This issue was discovered by Oleksandr Tyshchenko of EPAM.
Applying the appropriate attached patch resolves this issue.
Note that patches for released versions are generally prepared to
apply to the stable branches, and may not apply cleanly to the most
recent release tarball. Downstreams are encouraged to update to the
tip of the stable branch before applying these patches.
xsa406-linux.patch Linux 3.13 - 5.19-rc
$ sha256sum xsa406*
we do not support xen on arm.