CVE Catalog

CVE-2026-52994

MediumCVSS 5.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.17%

7th percentile - higher than 7% of all known CVEs

Summary

In the Linux kernel, the vsock/virtio driver had a bug in virtio_transport_init_zcopy_skb() that used an already-consumed iterator (iter->count) for pinned-pages accounting, skipping RLIMIT_MEMLOCK enforcement on the last skb. This could lead to uncontrolled memory usage.

Risk Assessment

The organization may face system memory exhaustion by processes using zero-copy in vsock sockets, potentially leading to denial of service (DoS) or system instability.

Recommendation

Immediately update the Linux kernel to a version containing the fix that explicitly passes pkt_len instead of iter->count to virtio_transport_init_zcopy_skb().

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: fix MSG_ZEROCOPY pinned-pages accounting virtio_transport_init_zcopy_skb() uses iter->count as the size argument for msg_zerocopy_realloc(), which in turn passes it to mm_account_pinned_pages() for RLIMIT_MEMLOCK accounting. However, this function is called after virtio_transport_fill_skb() has already consumed the iterator via __zerocopy_sg_from_iter(), so on the last skb, iter->count will be 0, skipping the RLIMIT_MEMLOCK enforcement. Pass pkt_len (the total bytes being sent) as an explicit parameter to virtio_transport_init_zcopy_skb() instead of reading the already-consumed iter->count. This matches TCP and UDP, which both call msg_zerocopy_realloc() with the original message size.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS