CVE-2026-74708: xsk: validate launch-time metadata size
In the Linux kernel, the following vulnerability has been resolved:
xsk: validate launch-time metadata size
Launch-time metadata extends beyond the first 16 bytes of struct xsktxmetadata. Reject the request when the registered metadata area does not contain the complete field.
Snapshot the validated flags for the generic transmit path and use that snapshot for request and completion processing, avoiding inconsistent decisions if user space changes the flags concurrently.
Note that only xskskbmetadata is properly using the flags, xskbuffgetmetadata ignores them. Next commits address that.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42~24.04.1 - Upgrade
Upgrade
ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1~24.04.1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-42.42 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1016.17 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1016.18 - Upgrade
Upgrade
ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
Upgrade
ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1015.16 - Upgrade
Upgrade
ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1
Event History
Frequently Asked Questions
What input condition is rejected by the fix?
The fix rejects a request when the registered metadata area does not contain the complete launch-time metadata field, which extends beyond the first 16 bytes of struct xsk_tx_metadata.
What concurrent behavior does the fix address?
It snapshots validated flags for generic transmit request and completion processing, preventing inconsistent decisions if user space modifies the flags concurrently.
Are all metadata access paths covered by the described flag handling?
No. The description states that xsk_skb_metadata properly uses the flags, while __xsk_buff_get_metadata ignores them; subsequent commits address that behavior.