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CVE Record

CVE-2022-49350: net: mdio: unexport __init-annotated mdio_bus_init()

In the Linux kernel, the following vulnerability has been resolved: net: mdio: unexport __init-annotated mdio_bus_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, drivers/net/phy/phy_device.c is never compiled as modular. (CONFIG_PHYLIB 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 Linux kernel issue can lead to a kernel panic when a loadable module tries to use a function that was discarded after boot initialization. The public record does not show remote attack paths, active exploitation, or CVSS scoring.

Executive priority

Handle through normal kernel patch governance unless custom kernel modules are used. Escalate for network appliances, embedded systems, or fleets with third-party kernel modules.

Technical view

mdio_bus_init() was exported while marked __init. After initialization, .init.text is freed, so later module access could reference freed kernel code and panic. The fix removes the export because the only in-tree caller is not modular.

Likely exposure

Exposure appears limited to Linux systems running affected kernels where a module can reference mdio_bus_init(). The source does not identify specific distributions, appliances, or remote-facing services as affected.

Exploitation context

CISA KEV is false in the provided bundle. The sources describe a build and symbol export problem that may cause kernel panic, but provide no evidence of public exploitation.

Researcher notes

The record lacks CVSS, CWE, and exploit evidence. The key condition is an exported __init symbol later callable by modules after init memory is freed; upstream fixed this by removing EXPORT_SYMBOL.

Mitigation direction

  • Apply Linux vendor or distribution kernel updates carrying the referenced stable fixes.
  • Prioritize systems using custom, third-party, or out-of-tree kernel modules.
  • Check vendor advisories for fixed package versions before production rollout.
  • Avoid relying on direct kernel.org commits if your distribution backports fixes.

Validation and detection

  • Inventory Linux kernel versions across servers, appliances, and embedded systems.
  • Confirm whether affected systems load custom or third-party PHY/MDIO-related modules.
  • Check distribution CVE trackers or package changelogs for CVE-2022-49350 fixes.
  • Review kernel module build warnings for invalid __init symbol references.
Prepared
Confidence
medium
Sources
5

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-2022-49350 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
9Source 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
LinuxLinux90eff9096c01ba90cdae504a6b95ee87fe2556a3, 90eff9096c01ba90cdae504a6b95ee87fe2556a3, 90eff9096c01ba90cdae504a6b95ee87fe2556a3, 90eff9096c01ba90cdae504a6b95ee87fe2556a3, 90eff9096c01ba90cdae504a6b95ee87fe2556a3, 90eff9096c01ba90cdae504a6b95ee87fe2556a3, 90eff9096c01ba90cdae504a6b95ee87fe2556a3, 90eff9096c01ba90cdae504a6b95ee87fe2556a3unaffected
LinuxLinux4.12, 0, 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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