xsk: honor XDP_TX_METADATA in zero-copy path

Summary

In the Linux kernel, the following vulnerability has been resolved: xsk: honor XDP_TX_METADATA in zero-copy path The zero-copy path reads TX metadata whenever the UMEM has metadata space, even if the descriptor does not set XDP_TX_METADATA. Pass descriptor options through the metadata helpers and ignore metadata unless the option is set. This does not fix the existing per-WQE metadata handling for mlx5 MPWQEs. Only the descriptor that starts a session passes through xsk_tx_metadata_request() and configures offload state shared by the batch. Metadata on descriptors joining an open session is therefore not validated and does not configure its requested offloads. In addition, a non-NULL metadata pointer from such a descriptor is treated as a timestamp completion request even when XDP_TXMD_FLAGS_TIMESTAMP is not set, so its metadata union can be overwritten with an unrequested timestamp. Fixing mixed metadata states within one MPWQE requires a separate change.

Timeline

1. Sep 17, 2026, 4:06 PM UTCCVE published
2. Oct 21, 2026, 12:49 PM UTCRecord last updated

Affected versions

• Linux Linux

  From 48eb03dd26304c24f03bdbb9382e89c8564e71df · fixed in 8ba0d143e471c85f8a116707c0b42bf046b0a7b3; From 48eb03dd26304c24f03bdbb9382e89c8564e71df · fixed in 53a5b262d706b572840cbe8feae392538077ee19; From 48eb03dd26304c24f03bdbb9382e89c8564e71df · fixed in bf9387488d6394845076928c6ca5315ce5d84f54; From 48eb03dd26304c24f03bdbb9382e89c8564e71df · fixed in a6e4b9a6deb9362ef7a0706c70d674e92fe1411a

• Linux Linux

  6.8

• KernelLinux

  From 6.8.0 · fixed in 6.12.114; From 6.13.0 · fixed in 6.18.52; From 6.19.0 · fixed in 7.2.6

References 4