Kernel: gve Driver QPL Mode Unmap OOB Causing UB
CVE-2026-23386 Published on March 25, 2026
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.
Products Associated with CVE-2026-23386
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Affected Versions
Linux:- Version a6fb8d5a8b6925f1e635818d3dd2d89531d4a058 and below 71511dae56a75ce161aa746741e5c498feaea393 is affected.
- Version a6fb8d5a8b6925f1e635818d3dd2d89531d4a058 and below c171f90f58974c784db25e0606051541cb71b7f0 is affected.
- Version a6fb8d5a8b6925f1e635818d3dd2d89531d4a058 and below 07e0c80e17ef781799e7cd5c41a7bf44f1bf6a5f is affected.
- Version a6fb8d5a8b6925f1e635818d3dd2d89531d4a058 and below 3744ebd8ffaa542ae8110fb449adcac0202f4cc8 is affected.
- Version a6fb8d5a8b6925f1e635818d3dd2d89531d4a058 and below fb868db5f4bccd7a78219313ab2917429f715cea is affected.
- Version 6.6 is affected.
- Before 6.6 is unaffected.
- Version 6.6.130, <= 6.6.* is unaffected.
- Version 6.12.78, <= 6.12.* is unaffected.
- Version 6.18.17, <= 6.18.* is unaffected.
- Version 6.19.7, <= 6.19.* is unaffected.
- Version 7.0-rc2, <= * is unaffected.