CVE-2026-74623

Summary

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

net: atlantic: free stranded TX buffers on ring deinit

aq_vec_deinit() drains the TX rings with a single aq_ring_tx_clean() call, which frees at most AQ_CFG_TX_CLEAN_BUDGET (256) descriptors and stops at hw_head, which no longer moves once aq_vec_stop() has stopped the hardware and NAPI. Completed descriptors beyond the budget and everything still posted in [hw_head, sw_tail) keep their skb or xdp_frame when the interface goes down: aq_vec_ring_free() then frees the buffer ring and the references are lost for good.

Today this is a silent memory leak on every interface down under TX/XDP_TX load. With the conversion of the RX path to page_pool posted for net-next it becomes much more visible: XDP_TX frames carry fragment references on the RX ring's page_pool, so a single stranded frame keeps the pool's inflight count above zero forever. page_pool_destroy() then never completes, the pool is leaked together with its pages, and "page_pool_release_retry() stalled pool shutdown" is warned every 60 seconds from that point on, on every ifdown, XDP detach or ring resize under XDP_TX load.

Bring back aq_ring_tx_deinit() as it was before the removal and use it for teardown again, with one extension: TX rings can hold xdp_frames nowadays, so release those too. They are returned with xdp_return_frame() since this runs in process context.

Affected Software

Weaknesses

References

• https://git.kernel.org/stable/c/a14ceebd13bf857bfca052bc5a6bd49e737912be
• https://git.kernel.org/stable/c/4f1c20873f70b4b22ef86dc38dad1fda8e169bcd
• https://git.kernel.org/stable/c/307d80193b4a4a75b8dc4e0d3162be3755abbed7
• https://git.kernel.org/stable/c/7a3e1481f4ee6c581bccc6bfc6c970aac5be7b0c
• https://git.kernel.org/stable/c/3447641d361dcc5511841d986ad4d849b2900d9b
• https://git.kernel.org/stable/c/b13202d401e1a20fec89b0cda733dcbaf279f79d
• https://git.kernel.org/stable/c/dd633280de7fdfd60dc4fcf63d04e2ad95b43269
• https://git.kernel.org/stable/c/452636ea5410a96e02ebaaf80b21e3620b98e0dd

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