CVE-2026-80977

Summary

In the Linux kernel, the following vulnerability has been resolved:

net: skbuff: don't touch shared zerocopy state in skb_tx_error()

skb_tx_error() completes the zerocopy uarg and clears SKBFL_ALL_ZEROCOPY, and skb_zcopy_downgrade_managed() clears SKBFL_MANAGED_FRAG_REFS. Both live in skb_shinfo(), which every clone shares, while the caller only owns the reference it is about to drop. Through a clone it tells the producer its pages are free and drops SKBFL_SHARED_FRAG for an skb that is still in flight.

Open vSwitch reaches this with a non-last OVS_ACTION_ATTR_RECIRC: clone_execute() sends a skb_clone() into ovs_dp_process_packet() while do_execute_actions() keeps forwarding the original, and skb_clone() does not privatise the frags here – skb_orphan_frags() returns early on SKBFL_DONT_ORPHAN. A flow miss on the clone then strips the marker from the packet still being forwarded, and a later local ESP delivery decrypts in place over frags it does not own privately.

Skip it for a cloned skb. Nothing is lost: skb_release_data() clears the zerocopy state once the last reference to the shared data goes.

Affected Software

Weaknesses

References

• https://git.kernel.org/stable/c/15aa81b390d401abf4b8211042470e9e92e3b7fb
• https://git.kernel.org/stable/c/288f9970670841044ab030104fa6b6ed159949d0
• https://git.kernel.org/stable/c/0370da114a9bc044e248b85c6809d1b5e0c1f7f9
• https://git.kernel.org/stable/c/f66bdb1cc0fcd227a062378f8be0b5873aa5600a

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