xen/netfront: drop RX packets with a short Ethernet header

Summary

In the Linux kernel, the following vulnerability has been resolved: xen/netfront: drop RX packets with a short Ethernet header handle_incoming_queue() pulls pull_to bytes into the head before calling eth_type_trans(). pull_to is the length of the first RX slot, capped at RX_COPY_THRESHOLD, and that length comes from the backend. Nothing checks it against ETH_HLEN. If the first slot is shorter than ETH_HLEN and more slots follow, the head ends up shorter than an Ethernet header while skb->len is longer, and eth_type_trans() BUG()s in __skb_pull(). If the whole packet is shorter than ETH_HLEN, eth_type_trans() reads the header past the end of the data instead. Pull at least ETH_HLEN, and drop the packet if that fails, which also drops packets too short to hold an Ethernet header. This also checks the return value of the pull, which was ignored.

Timeline

1. Oct 9, 2026, 7:10 AM UTCCVE published
2. Oct 21, 2026, 12:54 PM UTCRecord last updated

Affected versions

• Linux Linux

  From 0d160211965b79de989cf2d170985abeb8da5ec6 · fixed in 0542d213253eec18785a24b603b28bd385dfe4a5; From 0d160211965b79de989cf2d170985abeb8da5ec6 · fixed in 236a17caebcff31f75bec5ff4136bde2de944e40; From 0d160211965b79de989cf2d170985abeb8da5ec6 · fixed in 72d2f54367895d6e236b9857892e2e6b6036e067; From 0d160211965b79de989cf2d170985abeb8da5ec6 · fixed in e2b721bc30f40ffa7ccc36a56d4e8990b8c0538e; From 0d160211965b79de989cf2d170985abeb8da5ec6 · fixed in 089e58805c452e52179482b1025a8e309a57f801

• Linux Linux

  2.6.23

• KernelLinux

  From 2.6.23 · fixed in 6.6.160; From 6.7.0 · fixed in 6.12.113; From 6.13.0 · fixed in 6.18.56; From 6.19.0 · fixed in 7.2.10

References 5