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CVE Record

CVE-2021-47345: RDMA/cma: Fix rdma_resolve_route() memory leak

In the Linux kernel, the following vulnerability has been resolved: RDMA/cma: Fix rdma_resolve_route() memory leak Fix a memory leak when "mda_resolve_route() is called more than once on the same "rdma_cm_id". This is possible if cma_query_handler() triggers the RDMA_CM_EVENT_ROUTE_ERROR flow which puts the state machine back and allows rdma_resolve_route() to be called again.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2021-47345 is a Linux kernel memory leak in the RDMA connection manager route-resolution path. On affected kernels, repeated route resolution after a route error can leak memory. The available sources do not show active exploitation or a CVSS score, so urgency depends mainly on whether RDMA is used in production.

Executive priority

Treat as a targeted kernel maintenance item, not an emergency, unless RDMA is business-critical or memory exhaustion would cause high-impact outages. Fold the fix into the next tested kernel update cycle for exposed fleets.

Technical view

The flaw is in RDMA/cma. If cma_query_handler() enters RDMA_CM_EVENT_ROUTE_ERROR, the state machine can allow rdma_resolve_route() to be called again on the same rdma_cm_id, leaking memory. Upstream stable kernel commits provide fixes across affected branches.

Likely exposure

Exposure is most likely on Linux systems running affected kernel versions with RDMA functionality in use. Systems without RDMA use appear lower priority, but the source bundle does not provide product-specific deployment conditions.

Exploitation context

The sources identify a kernel memory leak condition, not a public exploit. CISA KEV status is false in the bundle, and no cited source reports active exploitation. Impact is most plausibly availability risk through memory exhaustion, but exploitability details are incomplete.

Researcher notes

Evidence is limited to the CVE description and upstream stable commits. There is no CVSS, CWE, exploit report, or vendor-specific advisory in the supplied bundle. Validate branch applicability using the referenced stable commits and local kernel provenance.

Mitigation direction

  • Update affected Linux kernels to vendor releases containing the referenced stable fixes.
  • Track distribution advisories for CVE-2021-47345 before changing production kernels.
  • Prioritize remediation for hosts using RDMA networking or RDMA CM paths.
  • If vendor packages lag, assess an upstream stable backport through normal kernel QA.

Validation and detection

  • Inventory Linux kernel versions against the affected versions listed in the CVE record.
  • Identify systems where RDMA kernel functionality is enabled or required.
  • Confirm installed kernel changelogs reference CVE-2021-47345 or the stable fix commits.
  • Monitor affected RDMA hosts for unexplained kernel memory growth before remediation.
Prepared
Confidence
medium
Sources
11

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.

ATT&CK lookup starting points

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CVE-2021-47345 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
2ADP providers
10Source links

SSVC decision data

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

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

CVECVE Program Container
CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxe51060f08a61965c4dd91516d82fe90617152590, e51060f08a61965c4dd91516d82fe90617152590, e51060f08a61965c4dd91516d82fe90617152590, e51060f08a61965c4dd91516d82fe90617152590, e51060f08a61965c4dd91516d82fe90617152590, e51060f08a61965c4dd91516d82fe90617152590, e51060f08a61965c4dd91516d82fe90617152590, e51060f08a61965c4dd91516d82fe90617152590, e51060f08a61965c4dd91516d82fe90617152590unaffected
LinuxLinux2.6.18, 0, 4.4.276, 4.9.276, 4.14.240, 4.19.198, 5.4.133, 5.10.51, 5.12.18, 5.13.3, 5.14affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.