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CVE Record

CVE-2022-49989: xen/privcmd: fix error exit of privcmd_ioctl_dm_op()

In the Linux kernel, the following vulnerability has been resolved: xen/privcmd: fix error exit of privcmd_ioctl_dm_op() The error exit of privcmd_ioctl_dm_op() is calling unlock_pages() potentially with pages being NULL, leading to a NULL dereference. Additionally lock_pages() doesn't check for pin_user_pages_fast() having been completely successful, resulting in potentially not locking all pages into memory. This could result in sporadic failures when using the related memory in user mode. Fix all of that by calling unlock_pages() always with the real number of pinned pages, which will be zero in case pages being NULL, and by checking the number of pages pinned by pin_user_pages_fast() matching the expected number of pages.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This Linux kernel issue affects Xen privcmd error handling. A failed operation can hit a NULL pointer and crash the relevant kernel path, and incomplete page pinning can cause unreliable user-mode behavior. The public record does not provide CVSS, CWE, or confirmed impact beyond those failure modes.

Executive priority

Treat this as a targeted Linux/Xen reliability risk until vendor scoring clarifies severity. Prioritize environments where Xen management or virtualization availability is business-critical, but do not treat it as known exploited based on the supplied evidence.

Technical view

The flaw is in xen/privcmd privcmd_ioctl_dm_op(). On error exit, unlock_pages() could be called with pages set to NULL. lock_pages() also failed to verify that pin_user_pages_fast() pinned the expected number of pages. Fixes pass the actual pinned-page count and validate full pinning.

Likely exposure

Exposure is most relevant to Linux systems using Xen privcmd functionality on affected kernel builds. The bundle lists Linux kernel versions and upstream stable commits, but does not map exposure to specific distributions, configurations, or packaged kernel releases.

Exploitation context

CISA KEV status is false in the provided bundle, and no cited source claims active exploitation. The sources describe a kernel bug and upstream fixes, not public exploit activity or weaponized use.

Researcher notes

The evidence supports a kernel NULL dereference and incomplete page-pinning validation bug in xen/privcmd. Missing CVSS, CWE, privilege requirements, and distro mappings limit confidence in exploitability and impact. Validate against exact kernel source or vendor backports.

Mitigation direction

  • Check Linux vendor advisories for kernels containing the referenced stable fixes.
  • Prioritize Xen hosts or systems using Xen privcmd functionality.
  • Apply supported kernel updates through normal change control.
  • If patch timing is unclear, ask the Linux distribution vendor for backport status.

Validation and detection

  • Inventory Linux kernel versions across Xen-related systems.
  • Confirm whether Xen privcmd functionality is present and operationally used.
  • Compare installed kernels against vendor-fixed releases or referenced upstream commits.
  • Review crash logs for related NULL dereference symptoms without assuming compromise.
Prepared
Confidence
medium
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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ATT&CK lookup starting points

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CVE-2022-49989 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
0ADP providers
5Source links

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxab520be8cd5d56867fc95cfbc34b90880faf1f9d, ab520be8cd5d56867fc95cfbc34b90880faf1f9d, ab520be8cd5d56867fc95cfbc34b90880faf1f9d, ab520be8cd5d56867fc95cfbc34b90880faf1f9dunaffected
LinuxLinux4.11, 0, 5.10.140, 5.15.64, 5.19.6, 6.0affected
Weakness

CWE details

No CWE listed

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