CVE-2026-81002xdp: fix zero-copy frame layout

Official description

In the Linux kernel, the following vulnerability has been resolved: xdp: fix zero-copy frame layout xdp_convert_zc_to_xdp_frame() clones an XSK packet into an order-0 page and advertises PAGE_SIZE as its frame size. It allows the copied frame to occupy the page tail needed by skb_shared_info and records zero headroom even when metadata separates the frame header from packet data. An AF_XDP zero-copy packet redirected through cpumap can therefore make the skb overlap skb_shared_info or place it beyond the allocated page. Limit the copied layout to SKB_WITH_OVERHEAD(PAGE_SIZE) and include the metadata length in frame headroom. Redirect callers already handle a NULL conversion result. BUG: KASAN: slab-out-of-bounds in skb_gro_receive Write of size 4 at addr ffff88800cf37004 by task cpumap/1/map:1/146 Call Trace: skb_gro_receive (net/core/gro.c:174) udp_gro_receive (net/ipv4/udp_offload.c:812) inet_gro_receive (net/ipv4/af_inet.c:1539) dev_gro_receive (net/core/gro.c:515) gro_receive_skb (net/core/gro.c:633) cpu_map_kthread_run (kernel/bpf/cpumap.c:395) kthread (kernel/kthread.c:436) ret_from_fork (arch/x86/kernel/process.c:164) ret_from_fork_asm (arch/x86/entry/entry_64.S:255) Kernel panic - not syncing: KASAN: panic_on_warn set ...

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/dcb6db9ca6515fcd3e00c93ec5e27dc7a0a7012f
• https://git.kernel.org/stable/c/22092730129077c302d8c947bbe0876f0280c528
• https://git.kernel.org/stable/c/ced3e18cd9b9caf630aaa1e1eac305f5192ba896
• https://git.kernel.org/stable/c/6de17275b3ccdf9887568b07e54da2e3597217cf
• https://git.kernel.org/stable/c/444216dacdbebd3e52d5e704facafbb230da09e9
• https://git.kernel.org/stable/c/15d1f3c0dbe7a740f779337deb39f23cd8d002c8
• https://git.kernel.org/stable/c/68d7cc5512238693670fc19c7a615df631e10edf
• https://git.kernel.org/stable/c/71283aaa6c65b3cec84caf1dc78560985737641f