vsock/virtio: bind uarg before filling zerocopy skb
Summary
| CVE | CVE-2026-63970 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-19 16:17:16 UTC |
| Updated | 2026-07-24 15:19:05 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: bind uarg before filling zerocopy skb virtio_transport_send_pkt_info() allocates or reuses the zerocopy uarg before entering the send loop, but virtio_transport_alloc_skb() still fills the skb before it inherits that uarg. When fixed-buffer vectored zerocopy hits MAX_SKB_FRAGS, io_sg_from_iter() may partially attach managed frags and return -EMSGSIZE. The rollback path call kfree_skb() to free an skb that carries SKBFL_MANAGED_FRAG_REFS but no uarg, so skb_release_data() falls through to ordinary frag unref. Pass the uarg into virtio_transport_alloc_skb() and bind it immediately before virtio_transport_fill_skb(). This keeps control or no-payload skbs untouched while ensuring success and rollback share one lifetime rule. |
Risk And Classification
Primary CVSS: v3.1 7.8 HIGH from 416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.001980000 probability, percentile 0.097890000 (date 2026-07-20)
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | Secondary | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | CNA | DECLARED | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 581512a6dc939ef122e49336626ae159f3b8a345 72194f65050958e4c8e069adb6c5d89ef81ca197 git | Not specified |
| CNA | Linux | Linux | affected 581512a6dc939ef122e49336626ae159f3b8a345 b62e2b2b4a50953ca952f3cd3f77dd62dc50fd5d git | Not specified |
| CNA | Linux | Linux | affected 581512a6dc939ef122e49336626ae159f3b8a345 5d317573f1d48e76cce5fb6250452b6e4102e0fb git | Not specified |
| CNA | Linux | Linux | affected 581512a6dc939ef122e49336626ae159f3b8a345 1e584c304cfb94a759417130b1fc6d30b30c4cce git | Not specified |
| CNA | Linux | Linux | affected 6.7 | Not specified |
| CNA | Linux | Linux | unaffected 6.7 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.97 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.35 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.0.12 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/5d317573f1d48e76cce5fb6250452b6e4102e0fb | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/1e584c304cfb94a759417130b1fc6d30b30c4cce | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/72194f65050958e4c8e069adb6c5d89ef81ca197 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/b62e2b2b4a50953ca952f3cd3f77dd62dc50fd5d | 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.