gve: fix incorrect buffer cleanup in gve_tx_clean_pending_packets for QPL

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

gve: fix incorrect buffer cleanup in gve_tx_clean_pending_packets for QPL

In DQ-QPL mode, gve_tx_clean_pending_packets() incorrectly uses the RDA

buffer cleanup path. It iterates num_bufs times and attempts to unmap

entries in the dma array.

This leads to two issues:

1. The dma array shares storage with tx_qpl_buf_ids (union).

Interpreting buffer IDs as DMA addresses results in attempting to

unmap incorrect memory locations.

2. num_bufs in QPL mode (counting 2K chunks) can significantly exceed

the size of the dma array, causing out-of-bounds access warnings

(trace below is how we noticed this issue).

UBSAN: array-index-out-of-bounds in

drivers/net/ethernet/drivers/net/ethernet/google/gve/gve_tx_dqo.c:178:5 index 18 is out of

range for type 'dma_addr_t[18]' (aka 'unsigned long long[18]')

Workqueue: gve gve_service_task [gve]

Call Trace:

<TASK>

dump_stack_lvl+0x33/0xa0

__ubsan_handle_out_of_bounds+0xdc/0x110

gve_tx_stop_ring_dqo+0x182/0x200 [gve]

gve_close+0x1be/0x450 [gve]

gve_reset+0x99/0x120 [gve]

gve_service_task+0x61/0x100 [gve]

process_scheduled_works+0x1e9/0x380

Fix this by properly checking for QPL mode and delegating to

gve_free_tx_qpl_bufs() to reclaim the buffers.