In mana_hwc_rx_event_handler(), rx_req_idx is derived from
sge->address in DMA-coherent memory. In Confidential VMs
(SEV-SNP/TDX), this memory is shared unencrypted and HW can modify
WQE contents at any time. No bounds check exists on rx_req_idx,
which can lead to an out-of-bounds access into reqs[].
Add bounds check on rx_req_idx in mana_hwc_rx_event_handler() before
using it to index the reqs[] array.
Fixes: ca9c54d2d6a5 ("net: mana: Add a driver for Microsoft Azure Network
Adapter (MANA)")
Signed-off-by: Aditya Garg <[email protected]>
Reviewed-by: Haiyang Zhang <[email protected]>
---
drivers/net/ethernet/microsoft/mana/hw_channel.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/net/ethernet/microsoft/mana/hw_channel.c
b/drivers/net/ethernet/microsoft/mana/hw_channel.c
index dbbde0fa57e7..a60f733d1a07 100644
--- a/drivers/net/ethernet/microsoft/mana/hw_channel.c
+++ b/drivers/net/ethernet/microsoft/mana/hw_channel.c
@@ -266,6 +266,12 @@ static void mana_hwc_rx_event_handler(void *ctx, u32
gdma_rxq_id,
rq_base_addr = hwc_rxq->msg_buf->mem_info.dma_handle;
rx_req_idx = (sge->address - rq_base_addr) / hwc->max_req_msg_size;
+ if (rx_req_idx >= hwc_rxq->msg_buf->num_reqs) {
+ dev_err(hwc->dev, "HWC RX: wrong rx_req_idx=%llu,
num_reqs=%u\n",
+ rx_req_idx, hwc_rxq->msg_buf->num_reqs);
+ return;
+ }
+
rx_req = &hwc_rxq->msg_buf->reqs[rx_req_idx];
resp = (struct gdma_resp_hdr *)rx_req->buf_va;
--
2.43.0
