[PATCH net-next] net: mana: hardening: Reject zero max_num_queues from MANA_QUERY_VPORT_CONFIG

[Erni Sri Satya Vennela <ernis@linux.microsoft.com>]

As a part of MANA hardening for CVM, validate that max_num_sq and
max_num_rq returned by MANA_QUERY_VPORT_CONFIG are not zero. These
values flow into apc->num_queues, which is used as an allocation count
and loop bound. A zero value would result in zero-size allocations and
incorrect driver behavior.

Return -EPROTO if either value is zero.

Signed-off-by: Erni Sri Satya Vennela <ernis@linux.microsoft.com>
---
 drivers/net/ethernet/microsoft/mana/mana_en.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index b39e8b920791..a4197b4b0597 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -1249,6 +1249,12 @@ static int mana_query_vport_cfg(struct mana_port_context *apc, u32 vport_index,
 
 	*max_sq = resp.max_num_sq;
 	*max_rq = resp.max_num_rq;
+
+	if (*max_sq == 0 || *max_rq == 0) {
+		netdev_err(apc->ndev, "Invalid max queues from vPort config\n");
+		return -EPROTO;
+	}
+
 	if (resp.num_indirection_ent > 0 &&
 	    resp.num_indirection_ent <= MANA_INDIRECT_TABLE_MAX_SIZE &&
 	    is_power_of_2(resp.num_indirection_ent)) {
-- 
2.34.1