# CVE-2026-45891: net: hns3: fix double free issue for tx spare buffer

Status: published. Published: 2026-05-27. Updated: 2026-11-06.

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

net: hns3: fix double free issue for tx spare buffer

In hns3_set_ringparam(), a temporary copy (tmp_rings) of the ring structure
is created for rollback. However, the tx_spare pointer in the original
ring handle is incorrectly left pointing to the old backup memory.

Later, if memory allocation fails in hns3_init_all_ring() during the setup,
the error path attempts to free all newly allocated rings. Since tx_spare
contains a stale (non-NULL) pointer from the backup, it is mistaken for
a newly allocated buffer and is erroneously freed, leading to a double-free
of the backup memory.

The root cause is that the tx_spare field was not cleared after its value
was saved in tmp_rings, leaving a dangling pointer.

Fix this by setting tx_spare to NULL in the original ring structure
when the creation of the new `tx_spare` fails. This ensures the
error cleanup path only frees genuinely newly allocated buffers.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Linux / Linux: ≥ 907676b130711fd1f627824559e92259db2061d1; < fb6a4c376d454b425555b1b0bda36e99f56ec307 (affected, git); ≥ 907676b130711fd1f627824559e92259db2061d1; < 43015461662d41dcfb3bb95fadd8a2a42ad8eacf (affected, git); ≥ 907676b130711fd1f627824559e92259db2061d1; < 6dc10494cfe27b6f1e9adb7e293293ae39c50b7c (affected, git); ≥ 907676b130711fd1f627824559e92259db2061d1; < d2c785733dfb853ea0b53984c75662a1af230a94 (affected, git); ≥ 907676b130711fd1f627824559e92259db2061d1; < fdbccddb7e7822016601829f95de4008e193f7bc (affected, git); ≥ 907676b130711fd1f627824559e92259db2061d1; < c3659273860bed0c8e573b865e3769abc51225a8 (affected, git); ≥ 907676b130711fd1f627824559e92259db2061d1; < 6d2f142b1e4b203387a92519d9d2e34752a79dbb (affected, git). Source: CNA: Linux
- Linux / Linux: 5.14 (affected); ≥ 0; < 5.14 (unaffected, semver); ≥ 5.15.202; ≤ 5.15.* (unaffected, semver); ≥ 6.1.165; ≤ 6.1.* (unaffected, semver); ≥ 6.6.128; ≤ 6.6.* (unaffected, semver); ≥ 6.12.75; ≤ 6.12.* (unaffected, semver); ≥ 6.18.14; ≤ 6.18.* (unaffected, semver); ≥ 6.19.4; ≤ 6.19.* (unaffected, semver); ≥ 7.0; ≤ * (unaffected, original_commit_for_fix). Source: CNA: Linux

## Severity and prioritization

- CISA KEV: No listing in collected sources

- EPSS: 0.13% as of 2026-11-06; percentile 2.63%

- 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/fb6a4c376d454b425555b1b0bda36e99f56ec307 (CNA: Linux)

- https://git.kernel.org/stable/c/43015461662d41dcfb3bb95fadd8a2a42ad8eacf (CNA: Linux)

- https://git.kernel.org/stable/c/6dc10494cfe27b6f1e9adb7e293293ae39c50b7c (CNA: Linux)

- https://git.kernel.org/stable/c/d2c785733dfb853ea0b53984c75662a1af230a94 (CNA: Linux)

- https://git.kernel.org/stable/c/fdbccddb7e7822016601829f95de4008e193f7bc (CNA: Linux)

- https://git.kernel.org/stable/c/c3659273860bed0c8e573b865e3769abc51225a8 (CNA: Linux)

- https://git.kernel.org/stable/c/6d2f142b1e4b203387a92519d9d2e34752a79dbb (CNA: Linux)

## Provenance

- CNA: Linux: https://www.cve.org/CVERecord?id=CVE-2026-45891; retrieved 2026-11-06; source updated 2026-11-06

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-45891; retrieved 2026-11-06; source updated Not reported

Revision: 8540caf1d1dd03e2a560f52d106739d41245fcf8fd68382ca620d2c7e2a6e465

Canonical: https://y2.dev/cve/CVE-2026-45891

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