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CVE Record

CVE-2022-49345: net: xfrm: unexport __init-annotated xfrm4_protocol_init()

In the Linux kernel, the following vulnerability has been resolved: net: xfrm: unexport __init-annotated xfrm4_protocol_init() EXPORT_SYMBOL and __init is a bad combination because the .init.text section is freed up after the initialization. Hence, modules cannot use symbols annotated __init. The access to a freed symbol may end up with kernel panic. modpost used to detect it, but it has been broken for a decade. Recently, I fixed modpost so it started to warn it again, then this showed up in linux-next builds. There are two ways to fix it: - Remove __init - Remove EXPORT_SYMBOL I chose the latter for this case because the only in-tree call-site, net/ipv4/xfrm4_policy.c is never compiled as modular. (CONFIG_XFRM is boolean)

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysislow

Security readout for executives and security teams

Plain-English summary

This is a Linux kernel reliability flaw in the network XFRM area. A function meant only for boot-time initialization was exported for later module use, even though its memory is freed after initialization. If used afterward, it could cause a kernel panic and service outage.

Executive priority

Treat this as routine kernel hygiene unless affected systems have strict availability requirements. There is no source evidence of exploitation, but kernel panic risk still matters for production resilience.

Technical view

The issue is the exported __init-annotated xfrm4_protocol_init() symbol. __init code is placed in .init.text and freed after initialization, so module access after boot can dereference freed kernel text. The upstream fix removes EXPORT_SYMBOL because the only in-tree caller is not modular under CONFIG_XFRM.

Likely exposure

Exposure is limited to Linux systems running affected kernel versions or downstream kernels that retained the bad export. The source lists Linux as affected and references stable kernel commits. Confirm exposure against the running kernel build and vendor backport status.

Exploitation context

The bundle does not show active exploitation, KEV listing, public exploit activity, CVSS, or CWE classification. The documented impact is potential kernel panic from access to a freed init symbol, not demonstrated remote code execution.

Researcher notes

The source evidence supports a freed init-text access risk caused by EXPORT_SYMBOL on an __init function. The fix rationale is explicit: remove the export because the in-tree caller is never modular. Evidence is incomplete for exploitability prerequisites and real-world reachability.

Mitigation direction

  • Update to a vendor kernel containing the referenced stable fix.
  • Check distribution advisories for backported patches before relying on version strings.
  • Prioritize hosts where kernel panics would cause critical outages.
  • Use normal kernel change windows and reboot procedures after patching.

Validation and detection

  • Inventory running Linux kernel versions across servers and appliances.
  • Compare kernel packages against vendor advisories or the referenced stable commits.
  • Confirm the xfrm4_protocol_init export is absent in patched kernel sources or symbols.
  • Review uptime and crash telemetry for unexplained kernel panics.
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

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CVE-2022-49345 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
10Source 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
LinuxLinux2f32b51b609faea1e40bb8c5bd305f1351740936, 2f32b51b609faea1e40bb8c5bd305f1351740936, 2f32b51b609faea1e40bb8c5bd305f1351740936, 2f32b51b609faea1e40bb8c5bd305f1351740936, 2f32b51b609faea1e40bb8c5bd305f1351740936, 2f32b51b609faea1e40bb8c5bd305f1351740936, 2f32b51b609faea1e40bb8c5bd305f1351740936, 2f32b51b609faea1e40bb8c5bd305f1351740936, 2f32b51b609faea1e40bb8c5bd305f1351740936unaffected
LinuxLinux3.15, 0, 4.9.318, 4.14.283, 4.19.247, 5.4.198, 5.10.122, 5.15.47, 5.17.15, 5.18.4, 5.19affected
Weakness

CWE details

No CWE listed

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