CVE-2026-99028
CVE-2026-99028CVE-2026-99028
Description
In the Linux kernel, the following vulnerability has been resolved:
net: xilinx: axienet: Free outstanding DMA buffers on dmaengine stop
In the dmaengine path the driver pre-submits RX buffers and holds
in-flight TX buffers whose SKBs are DMA-mapped by the driver and freed
only in the completion callbacks. On ndo_stop() dmaengine_terminate_sync()
aborts these descriptors without running their callbacks, and the driver
then frees only the ring shells, leaking every SKB still owned by the
engine and its DMA mapping on each ifdown. With 128 RX buffers pre-posted
per channel, the mapping leak can eventually exhaust a limited IOMMU
aperture.
Clear the slot's skb in the TX and RX callbacks so a non-NULL skb marks a
slot that still owns a live, DMA-mapped buffer, and on stop unmap and free
every such buffer.
axienet_dma_rx_cb() runs from the DMA tasklet and re-arms the RX ring on
each completion, so it can race axienet_stop(): a completion may submit a
fresh buffer after dmaengine_termina
Scoring
| Last modified | 2026-10-23 |