# CVE-2022-50043: net: fix potential refcount leak in ndisc_router_discovery()

Status: published. Published: 2025-06-18. Updated: 2026-11-05.

In the Linux kernel, the following vulnerability has been resolved:

net: fix potential refcount leak in ndisc_router_discovery()

The issue happens on specific paths in the function. After both the
object `rt` and `neigh` are grabbed successfully, when `lifetime` is
nonzero but the metric needs change, the function just deletes the
route and set `rt` to NULL. Then, it may try grabbing `rt` and `neigh`
again if above conditions hold. The function simply overwrite `neigh`
if succeeds or returns if fails, without decreasing the reference
count of previous `neigh`. This may result in memory leaks.

Fix it by decrementing the reference count of `neigh` in place.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Linux / Linux: ≥ 6b2e04bc240fe9be9e690059f710e9f95346d34d; < ffb15594433391fd7885eb88ce5a7f7bdeefbb15 (affected, git); ≥ 6b2e04bc240fe9be9e690059f710e9f95346d34d; < 7998043d31d000c3a93f46182e6569dd0eecda34 (affected, git); ≥ 6b2e04bc240fe9be9e690059f710e9f95346d34d; < 7396ba87f1edf549284869451665c7c4e74ecd4f (affected, git). Source: CNA: Linux
- Linux / Linux: 5.12 (affected); ≥ 0; < 5.12 (unaffected, semver); ≥ 5.15.63; ≤ 5.15.* (unaffected, semver); ≥ 5.19.4; ≤ 5.19.* (unaffected, semver); ≥ 6.0; ≤ * (unaffected, original_commit_for_fix). Source: CNA: Linux

## Severity and prioritization

- CISA KEV: No listing in collected sources

- EPSS: 0.19% as of 2026-11-05; percentile 9.27%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: Not reported

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://git.kernel.org/stable/c/ffb15594433391fd7885eb88ce5a7f7bdeefbb15 (CNA: Linux)

- https://git.kernel.org/stable/c/7998043d31d000c3a93f46182e6569dd0eecda34 (CNA: Linux)

- https://git.kernel.org/stable/c/7396ba87f1edf549284869451665c7c4e74ecd4f (CNA: Linux)

## Provenance

- CNA: Linux: https://www.cve.org/CVERecord?id=CVE-2022-50043; retrieved 2026-11-05; source updated 2026-11-05

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2022-50043; retrieved 2026-11-05; source updated Not reported

Revision: cb0e5bf1ce55b35a9f91c82250c74fbde710c3b118484765068fded0ede037f6

Canonical: https://y2.dev/cve/CVE-2022-50043

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