CVE-2026-74616xdp: reject clones that overrun skb_shared_info tailroom

Official description

In the Linux kernel, the following vulnerability has been resolved: xdp: reject clones that overrun skb_shared_info tailroom xdpf_clone() clones broadcast copies into a single page and sets frame_sz to PAGE_SIZE. __xdp_build_skb_from_frame() later treats that page like a normal XDP frame and expects the usual skb_shared_info tailroom at the end of the buffer. The current check only rejects frames whose linear xdp_frame header, headroom, and packet data exceed PAGE_SIZE. A source frame backed by a larger allocation can still satisfy that check while extending into the clone's required shared-info area. When such a clone is converted back into an skb, build_skb_around() places skb_shared_info over live packet bytes and later writes can corrupt XDP return metadata. Reject clones unless their linear area fits inside SKB_WITH_OVERHEAD(PAGE_SIZE), matching the tailroom requirement already enforced by the XDP-to-skb conversion path.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/58408982fa39f9758124cec169f42854d6f98f35
• https://git.kernel.org/stable/c/685edea27ac68d08fe4dbd3de74b858d2ad8e830
• https://git.kernel.org/stable/c/ba13763d667e008e185fedf592d53846a5b457d1
• https://git.kernel.org/stable/c/ef4b7c7046d29a67090de15af0da0d1ae8d1b192
• https://git.kernel.org/stable/c/fab820f1691a9e26d9031f18aae1e9ce09078f92
• https://git.kernel.org/stable/c/f463b6f4957c9c3fd1c75f8d3e5af4879fa609c0
• https://git.kernel.org/stable/c/e48e8edbef2eb824201495daa5234560f632b23c