Use After Free Affecting kernel-devel-matched package, versions <0:6.12.0-211.64.1.el10_2


Severity

Recommended
high

Based on AlmaLinux security rating.

Threat Intelligence

EPSS
0.18% (8th percentile)

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  • Snyk IDSNYK-ALMALINUX10-KERNELDEVELMATCHED-20726810
  • published10 Oct 2026
  • disclosed7 Oct 2026

Introduced: 7 Oct 2026

NewCVE-2026-63970  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade AlmaLinux:10 kernel-devel-matched to version 0:6.12.0-211.64.1.el10_2 or higher.
This issue was patched in ALSA-2026:77690.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-devel-matched package and not the kernel-devel-matched package as distributed by AlmaLinux. See How to fix? for AlmaLinux:10 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1