Bug 1746708 (CVE-2019-14821) - CVE-2019-14821 Kernel: KVM: OOB memory access via mmio ring buffer
Summary: CVE-2019-14821 Kernel: KVM: OOB memory access via mmio ring buffer
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2019-14821
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1746798 1746799 1746802 1746803 1753275 1755214 1755790 1746797 1746801 1746804 1746819 1746820 1746822 1746823 1753276 1753596
Blocks: 1746396
TreeView+ depends on / blocked
 
Reported: 2019-08-29 07:03 UTC by Prasad J Pandit
Modified: 2019-12-11 06:15 UTC (History)
53 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
An out-of-bounds access issue was found in the way Linux kernel's KVM hypervisor implements the Coalesced MMIO write operation. It operates on an MMIO ring buffer 'struct kvm_coalesced_mmio' object, wherein write indices 'ring->first' and 'ring->last' value could be supplied by a host user-space process. An unprivileged host user or process with access to '/dev/kvm' device could use this flaw to crash the host kernel, resulting in a denial of service or potentially escalating privileges on the system.
Clone Of:
Environment:
Last Closed: 2019-11-06 00:53:22 UTC


Attachments (Terms of Use)


Links
System ID Priority Status Summary Last Updated
Red Hat Product Errata RHBA-2019:4029 None None None 2019-12-02 10:16:51 UTC
Red Hat Product Errata RHBA-2019:4033 None None None 2019-12-02 10:33:15 UTC
Red Hat Product Errata RHBA-2019:4038 None None None 2019-12-02 17:55:16 UTC
Red Hat Product Errata RHBA-2019:4060 None None None 2019-12-03 08:47:00 UTC
Red Hat Product Errata RHSA-2019:3309 None None None 2019-11-05 20:35:53 UTC
Red Hat Product Errata RHSA-2019:3517 None None None 2019-11-05 21:06:35 UTC
Red Hat Product Errata RHSA-2019:3978 None None None 2019-11-26 13:58:42 UTC
Red Hat Product Errata RHSA-2019:3979 None None None 2019-11-26 12:50:51 UTC
Red Hat Product Errata RHSA-2019:4154 None None None 2019-12-10 12:02:29 UTC

Description Prasad J Pandit 2019-08-29 07:03:01 UTC
An out-of-bounds access issue was found in the way Linux kernel's KVM hypervisor
implements Coalesced MMIO write operation. It operates on a MMIO ring buffer
'struct kvm_coalesced_mmio' object, wherein write indices 'ring->first' and
'ring->last' value could be supplied by a host user-space process.

An unprivileged host user/process with access to '/dev/kvm' device could use this flaw
to crash the host kernel resulting in DoS OR potentially escalate privileges on the
system.

Upstream patch:
---------------
  -> https://git.kernel.org/pub/scm/virt/kvm/kvm.git/commit/?id=b60fe990c6b07ef6d4df67bc0530c7c90a62623a

Reference:
----------
  -> https://www.openwall.com/lists/oss-security/2019/09/20/1

Comment 2 Prasad J Pandit 2019-08-29 07:06:29 UTC
Acknowledgments:

Name: Matt Delco (Google.com)

Comment 10 Prasad J Pandit 2019-09-19 11:28:00 UTC
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1753596]

Comment 11 Prasad J Pandit 2019-09-20 11:43:52 UTC
Mitigation:

Restrict access to the '/dev/kvm' device to trusted users.

Comment 12 Prasad J Pandit 2019-09-20 11:47:29 UTC
Statement:

This issue requires unprivileged users to have access to '/dev/kvm' device. So restricting access to '/dev/kvm' device to known trusted users could limit its exploitation by untrusted users/processes.

Comment 13 errata-xmlrpc 2019-11-05 20:35:50 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2019:3309 https://access.redhat.com/errata/RHSA-2019:3309

Comment 14 errata-xmlrpc 2019-11-05 21:06:33 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2019:3517 https://access.redhat.com/errata/RHSA-2019:3517

Comment 15 Product Security DevOps Team 2019-11-06 00:53:22 UTC
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2019-14821

Comment 16 errata-xmlrpc 2019-11-26 12:50:48 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2019:3979 https://access.redhat.com/errata/RHSA-2019:3979

Comment 17 errata-xmlrpc 2019-11-26 13:58:38 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2019:3978 https://access.redhat.com/errata/RHSA-2019:3978

Comment 18 errata-xmlrpc 2019-12-10 12:02:25 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2019:4154 https://access.redhat.com/errata/RHSA-2019:4154


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