In the Linux kernel, the following vulnerability has been resolved:
net: tls: fix off-by-one in sgchain entry count for wrapped skmsg ring
When an skmsg scatterlist ring wraps (sg.end < sg.start), tlspushrecord() chains the tail portion of the ring to the head using sgchain(). An extra entry in the sg array is reserved for this:
struct skmsgsg { [...] /* The extra two elements: * 1) used for chaining the front and sections when the list becomes * partitioned (e.g. end < start). The crypto APIs require the * chaining; * 2) to chain tailer SG entries after the message. */ struct scatterlist data[MAXMSGFRAGS + 2];
The current code uses MAXSKBFRAGS + 1 as the ring size:
sg_chain(&msg_pl->sg.data[msg_pl->sg.start],
MAX_SKB_FRAGS - msg_pl->sg.start + 1,
msg_pl->sg.data);
This places the chain pointer at
sgchain(data[start], (MAXSKBFRAGS - msgstart + 1) .. = &data[start] + (MAXSKBFRAGS - msgstart + 1) - 1 = data[start + (MAXSKBFRAGS - start + 1) - 1] = data[MAXSKB_FRAGS]
instead of the true last entry. This is likely due to a "race" of the commit under Fixes landing close to commit 031097d9e079 ("bpf: sk_msg, zap ingress queue on psock down")
Convert to ARRAY_SIZE and drop the data[start] / - start (as suggested by Sabrina).
{
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64047.json",
"cna_assigner": "Linux"
}