esp: do not unref managed frag pages in esp_ssg_unref()
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 6 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: esp: do not unref managed frag pages in esp_ssg_unref() esp_ssg_unref() releases the page references held on the source scatterlist after the AEAD operation completes. It calls skb_page_unref() on every frag page for an out-of-place transform (req->src != req->dst), and in the error path of esp_output_tail() (already_unref == true) on the request's own scatterlist. This is wrong when the skb carries managed frags (SKBFL_MANAGED_FRAG_REFS). Managed frags are owned by a zerocopy ubuf and the skb does not hold a per-frag page reference; io_uring SEND_ZC with a registered buffer attaches the bvec pages this way via io_sg_from_iter(). The rest of the stack honours this invariant: skb_release_data() skips the per-frag unref when SKBFL_MANAGED_FRAG_REFS is set, and skb_zcopy_managed() is the guard used at the other unref sites. esp_ssg_unref() is missing that guard, so for a managed-frag skb it drops a page reference the skb never acquired. This can underflow the page reference count and free a page that is still in use. Guard the function with skb_zcopy_managed() so both unref paths are skipped for managed-frag skbs, matching skb_release_data().
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.1.191, 6.6.160, 6.12.114, 6.18.57, 7.2.6, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet |
Not affected: 1 product
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2026-93105
- 2026-10-03 Alias added: GHSA-m483-33mw-4p7w
- 2026-10-16 Fix available: Linux/Linux@1ad6456898f6e6cf58be83bdb607acb1119a9cd1, Linux/[email protected] · CNA
- 2026-10-16 1 new reference · CNA
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-20 Affected versions changed · Red Hat
- 2026-10-20 CVSS score added · Red Hat
- 2026-10-21 Fix available: Linux/Linux@201bdf10ae92e7cbd524adf8c0323e2a963d5fd7, Linux/Linux@3ec55f0c8a6a543cf660584d1346e11f6311ee59, Linux/[email protected] +1 · CNA
- 2026-10-21 2 new references · CNA
- 2026-10-30 Affected versions changed · Red Hat
- 2026-10-30 Fix available: Linux/[email protected], Linux/Linux@cb375965800d474c0281a2e92c43c724fce9f463 · CNA
- 2026-10-30 1 new reference · CNA
References
Other 6
- https://git.kernel.org/stable/c/cb375965800d474c0281a2e92c43c724fce9f463
- https://git.kernel.org/stable/c/201bdf10ae92e7cbd524adf8c0323e2a963d5fd7
- https://git.kernel.org/stable/c/3ec55f0c8a6a543cf660584d1346e11f6311ee59
- https://git.kernel.org/stable/c/1ad6456898f6e6cf58be83bdb607acb1119a9cd1
- https://git.kernel.org/stable/c/26b6b14c7a0368e317a1e9fb5144ebe6f8d495cf
- https://git.kernel.org/stable/c/21697720ff43b8dfa25b8e8d9ca7f56f4597fc80
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Sources
- CVE-2026-93105 · CVE Program
- CVE-2026-93105 · NVD
- FIRST EPSS
- GHSA-m483-33mw-4p7w · GitHub Advisory Database · CC BY 4.0
- CVE-2026-93105 · Red Hat security data · CC BY 4.0
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