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CVE Record

CVE-2022-49366: ksmbd: fix reference count leak in smb_check_perm_dacl()

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix reference count leak in smb_check_perm_dacl() The issue happens in a specific path in smb_check_perm_dacl(). When "id" and "uid" have the same value, the function simply jumps out of the loop without decrementing the reference count of the object "posix_acls", which is increased by get_acl() earlier. This may result in memory leaks. Fix it by decreasing the reference count of "posix_acls" before jumping to label "check_access_bits".

MediumCVSS 5.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2022-49366 is a Linux kernel ksmbd memory leak in SMB permission checking. Under a specific identity comparison path, an ACL reference is not released. The rated impact is availability loss, not data theft or integrity change.

Executive priority

Treat as a normal availability patching item, not an emergency. Prioritize exposed file-sharing hosts and shared Linux environments, especially where ksmbd is enabled.

Technical view

The flaw is in smb_check_perm_dacl(). get_acl() increments the posix_acls reference count, but when id and uid match the loop exits without decrementing it. The resolved fix releases posix_acls before continuing to check_access_bits.

Likely exposure

Exposure is most relevant to Linux systems running affected 5.15 through 5.19-era kernels with ksmbd present or enabled. The provided CVSS vector rates attack vector as local with low privileges required.

Exploitation context

The source bundle does not show known active exploitation, and KEV is false. It also does not provide exploit evidence. The main security concern is resource exhaustion through repeated triggering, causing memory pressure or service instability.

Researcher notes

Evidence is limited to the CVE record and Linux stable commits. The affected-version data is sparse, so distro backport status must be verified with each vendor rather than inferred from version strings alone.

Mitigation direction

  • Apply vendor or distribution kernel updates containing the referenced stable fixes.
  • If ksmbd is unnecessary, disable or remove it according to vendor guidance.
  • Prioritize internet-adjacent or multi-user systems where ksmbd is enabled.
  • Monitor affected hosts for unusual memory growth or availability degradation.

Validation and detection

  • Inventory Linux kernel versions across servers and appliances.
  • Confirm whether ksmbd is enabled, loaded, or packaged on each host.
  • Check vendor advisories for backported fixes to supported kernel builds.
  • Validate patched kernels include one of the referenced stable commits.
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

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

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CVE-2022-49366 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
5.5 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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.

1CVSS vectors
3Timeline events
1ADP providers
5Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
5.5CVSS 3.1MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H1.83.6CISA-ADP

Vulnerability scoring details

Base CVSS 3.1 score

5.5Medium
CVSS 3.1 vector shape for CVE-2022-49366Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

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.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
cvssV3_1other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux777cad1604d68ed4379ec899d1f7d2f6a29f01f0, 777cad1604d68ed4379ec899d1f7d2f6a29f01f0, 777cad1604d68ed4379ec899d1f7d2f6a29f01f0, 777cad1604d68ed4379ec899d1f7d2f6a29f01f0unaffected
LinuxLinux5.15, 0, 5.15.47, 5.17.15, 5.18.4, 5.19affected
Weakness

CWE details

No CWE listed

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