Bug 1771442 (CVE-2019-18422) - CVE-2019-18422 xen: ARM: Interrupts are unconditionally unmasked in exception handlers
Summary: CVE-2019-18422 xen: ARM: Interrupts are unconditionally unmasked in exception...
Keywords:
Status: CLOSED NOTABUG
Alias: CVE-2019-18422
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1771443
Blocks: 1762982
TreeView+ depends on / blocked
 
Reported: 2019-11-12 11:40 UTC by Marian Rehak
Modified: 2020-02-24 15:13 UTC (History)
23 users (show)

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Last Closed: 2020-02-24 15:13:50 UTC


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Description Marian Rehak 2019-11-12 11:40:38 UTC
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.

Upstream issue and patch:

http://xenbits.xen.org/xsa/advisory-303.html

Comment 1 Marian Rehak 2019-11-12 11:40:49 UTC
Created xen tracking bugs for this issue:

Affects: fedora-all [bug 1771443]


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