CVE Catalog

CVE-2026-99062

Unknown
Published: Translated: NVD NIST

Summary

In the Linux kernel, virtio_transport_read_skb() in vsock/virtio subtracts the full packet length from rx_bytes instead of only the unread bytes, underflowing the counter. This causes incorrect SIOCINQ reports (e.g. -40), wrong recv/poll behavior, and hiding of queued data.

Risk Assessment

Incorrect accounting can cause misbehavior in applications using vsock, including data loss or hiding and incorrect socket state reporting. It affects transmission integrity.

Recommendation

Update the Linux kernel to a version containing the fix that subtracts only skb->len minus the VSOCK offset from rx_bytes.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: account only unread bytes in read_skb() After a partial stream receive, rx_bytes tracks the unread suffix while buf_used and peer credit still cover the whole packet. virtio_transport_read_skb() dequeues that packet but passes pkt_len for both counters, underflowing rx_bytes. On a connected CID_LOCAL stream with an SK_SKB verdict, a 40-byte read from a 100-byte packet made SIOCINQ report -40, an empty recv return ELOOP, and poll report the empty socket readable. After verdict detach, receiving 40 bytes wrapped the counter to zero and hid those queued bytes until one more byte arrived. The fixed run kept the counter balanced and exposed all queued data immediately. This was found during an LLM-assisted manual source audit of VSOCK receive accounting while re-evaluating virtio_transport_read_skb() after CVE-2024-50169. Subtract only skb->len minus the VSOCK offset from rx_bytes. Retain the full packet length for buf_used and peer credit.

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