An issue was discovered in Xen through 4.12.x allowing ARM guest OS users
to cause a denial of service or gain privileges by leveraging the erroneous
enabling of interrupts. Interrupts are unconditionally unmasked in
exception handlers. When an exception occurs on an ARM system which is
handled without changing processor level, some interrupts are
unconditionally enabled during exception entry. So exceptions which occur
when interrupts are masked will effectively unmask the interrupts. A
malicious guest might contrive to arrange for critical Xen code to run with
interrupts erroneously enabled. This could lead to data corruption, denial
of service, or possibly even privilege escalation. However a precise attack
technique has not been identified.
mdeslaurhypervisor packages are in universe
amurrayThis issue is specific only to ARM platforms - x86 systems are not affected
Source: xen (LP Ubuntu Debian)
Ubuntu 12.04 ESM (Precise Pangolin):DNE
Ubuntu 14.04 ESM (Trusty Tahr):DNE
Ubuntu 16.04 LTS (Xenial Xerus):needs-triage
Ubuntu 18.04 LTS (Bionic Beaver):needs-triage
Ubuntu 20.04 LTS (Focal Fossa):not-affected (4.11.3+24-g14b62ab3e5-1ubuntu1)
Ubuntu 20.10 (Groovy Gorilla):not-affected (4.11.3+24-g14b62ab3e5-1ubuntu1)
Binaries built from this source package are in universe and so are supported by the community. For more details see
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Updated: 2020-07-28 18:56:06 UTC (commit 7b6828437fde0509248708fcdb5b0f7587b85bd1)