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.

A flaw was found in the Linux kernel's `vsock/virtio` component. This vulnerability involves an accounting error in the `MSG_ZEROCOPY` pinned-pages mechanism, where the system's resource limit for locked memory (`RLIMIT_MEMLOCK`) may not be properly enforced. This could allow a local attacker or a malicious virtual machine guest to bypass memory locking restrictions, potentially leading to resource exhaustion or a denial of service (DoS) condition.

Red Hat Enterprise Linux 10 Fix deferred kernel Red Hat Enterprise Linux 6 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel-rt Red Hat Enterprise Linux 8 Not affected kernel Red Hat Enterprise Linux 8 Not affected kernel-rt Red Hat Enterprise Linux 9 Fix deferred kernel Red Hat Enterprise Linux 9 Fix deferred kernel-rt https://www.cve.org/CVERecord?id=CVE-2026-52994 https://nvd.nist.gov/vuln/detail/CVE-2026-52994 https://lore.kernel.org/linux-cve-announce/2026062445-CVE-2026-52994-fe3c@gregkh/T