ipv6: ioam: refresh hdr pointer before ioam6_event()
Summary
| CVE | CVE-2026-64132 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-19 16:17:55 UTC |
| Updated | 2026-07-30 14:59:47 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: ipv6: ioam: refresh hdr pointer before ioam6_event() Reported by Sashiko: In ipv6_hop_ioam(), the hdr pointer is initialized to point into the skb's linear data buffer. Later, the code calls skb_ensure_writable(), which might reallocate the buffer: if (skb_ensure_writable(skb, optoff + 2 + hdr->opt_len)) goto drop; /* Trace pointer may have changed */ trace = (struct ioam6_trace_hdr *)(skb_network_header(skb) + optoff + sizeof(*hdr)); ioam6_fill_trace_data(skb, ns, trace, true); ioam6_event(IOAM6_EVENT_TRACE, dev_net(skb->dev), GFP_ATOMIC, (void *)trace, hdr->opt_len - 2); If the skb is cloned or lacks sufficient linear headroom, skb_ensure_writable() will invoke pskb_expand_head(), which reallocates the skb's data buffer and frees the old one, invalidating pointers to it. While the code recalculates the trace pointer immediately after the call to skb_ensure_writable(), it fails to recalculate the hdr pointer. This patch fixes the above by recalculating the hdr pointer before passing hdr->opt_len to ioam6_event(), so that we avoid any UaF. |
Risk And Classification
Primary CVSS: v3.1 9.8 CRITICAL from 416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.004910000 probability, percentile 0.395280000 (date 2026-08-02)
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | Secondary | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | CNA | DECLARED | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected f655c78d6225f585ef60a9d93ffb79d507ff3ad3 769723124b7c3b2bfea4cf68ad292698b87c8d01 git | Not specified |
| CNA | Linux | Linux | affected f655c78d6225f585ef60a9d93ffb79d507ff3ad3 24de676da63c1122d2c13b0d546238b66d1b4e62 git | Not specified |
| CNA | Linux | Linux | affected f655c78d6225f585ef60a9d93ffb79d507ff3ad3 5af905aa8e91ff8d94572a1e089558f21dcf24ed git | Not specified |
| CNA | Linux | Linux | affected f655c78d6225f585ef60a9d93ffb79d507ff3ad3 e46e6bc97fb1f339730ff1ba74267fbf48e7a422 git | Not specified |
| CNA | Linux | Linux | affected 6.9 | Not specified |
| CNA | Linux | Linux | unaffected 6.9 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.92 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.34 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.0.11 7.0.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/5af905aa8e91ff8d94572a1e089558f21dcf24ed | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/24de676da63c1122d2c13b0d546238b66d1b4e62 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/e46e6bc97fb1f339730ff1ba74267fbf48e7a422 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/769723124b7c3b2bfea4cf68ad292698b87c8d01 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.