In the Linux kernel, the following vulnerability has been resolved: net: gro: don't merge zcopy skbs skb_gro_receive() can currently copy frags between the source and GRO skb, without checking the zerocopy status, and in particular the SKBFL_MANAGED_FRAG_REFS flag. When SKBFL_MANAGED_FRAG_REFS is set, the skb doesn't hold a reference on the pages in shinfo->frags. Appending those frags to another skb's frags without fixing up the page refcount can lead to UAF. When either the last skb in the GRO chain (the one we would append frags to) or the source skb is zerocopy, don't merge the skbs.
https://git.kernel.org/stable/c/e334cbf3388fd9334503a778a82d9e9f14dd2f71
https://git.kernel.org/stable/c/4db79a322db8c97f7b73b8a347395ef4d685eb40
https://git.kernel.org/stable/c/479084ae0e1d9cb7929cb4298d35623de189f80a
https://git.kernel.org/stable/c/44bea2032af0425e4ce6d26a8af0ede79db49ec1
https://git.kernel.org/stable/c/1f9c828556416fbe3f49386708ce999fc4d4da06