[PATCH v0] qed/qed_dev: guard against a possible division by zero

From: Daniil Tatianin
Date: Thu Feb 09 2023 - 05:39:18 EST


Previously we would divide total_left_rate by zero if num_vports
happened to be 1 because non_requested_count is calculated as
num_vports - req_count. Guard against this by explicitly checking for
zero when doing the division.

Found by Linux Verification Center (linuxtesting.org) with the SVACE
static analysis tool.

Fixes: bcd197c81f63 ("qed: Add vport WFQ configuration APIs")
Signed-off-by: Daniil Tatianin <d-tatianin@xxxxxxxxxxxxxx>
---
drivers/net/ethernet/qlogic/qed/qed_dev.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/qlogic/qed/qed_dev.c b/drivers/net/ethernet/qlogic/qed/qed_dev.c
index d61cd32ec3b6..90927f68c459 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_dev.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_dev.c
@@ -5123,7 +5123,7 @@ static int qed_init_wfq_param(struct qed_hwfn *p_hwfn,

total_left_rate = min_pf_rate - total_req_min_rate;

- left_rate_per_vp = total_left_rate / non_requested_count;
+ left_rate_per_vp = total_left_rate / (non_requested_count ?: 1);
if (left_rate_per_vp < min_pf_rate / QED_WFQ_UNIT) {
DP_VERBOSE(p_hwfn, NETIF_MSG_LINK,
"Non WFQ configured vports rate [%d Mbps] is less than one percent of configured PF min rate[%d Mbps]\n",
--
2.25.1