Bug 1771344 (CVE-2019-18423)

Summary: CVE-2019-18423 xen: add-to-physmap can be abused to DoS Arm hosts
Product: [Other] Security Response Reporter: Marian Rehak <mrehak>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED NOTABUG QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: acaringi, ailan, bhu, brdeoliv, dhoward, drjones, dvlasenk, fhrbata, hkrzesin, imammedo, jforbes, jshortt, jstancek, knoel, m.a.young, mrezanin, nmurray, pbonzini, rkrcmar, robinlee.sysu, rvrbovsk, vkuznets, xen-maint
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Last Closed: 2020-02-24 15:11:11 UTC Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Bug Depends On: 1771345    
Bug Blocks: 1762982    

Description Marian Rehak 2019-11-12 08:39:45 UTC
The problem could be triggered with a specially crafted hypercall XENMEM_add_to_physmap{, _batch} followed by an access to an address (via hypercall or direct access) that passes the sanity check but cause p2m_get_root_pointer() to return NULL.

Upstream advisory and patch:

http://xenbits.xen.org/xsa/advisory-301.html

Comment 1 Marian Rehak 2019-11-12 08:39:56 UTC
Created xen tracking bugs for this issue:

Affects: fedora-all [bug 1771345]

Comment 2 Marian Rehak 2019-11-12 08:44:56 UTC
Xen version 4.8 and newer are vulnerable.
Only Arm systems are vulnerable. x86 systems are not affected.