Subject: [PATCH v2][next] octeontx2-pf: Fix out-of-bounds read warning in otx2_get_fecparam()

From: "Gustavo A. R. Silva" <[email-masked]>
Date: Fri, 12 Feb 2021 09:06:19 -0600

Line at 967 implies that rsp->fwdata.supported_fec may be up to 4:

if (rsp->fwdata.supported_fec <= FEC_MAX_INDEX)

which would cause an out-of-bounds read at line 971:

fecparam->fec = fec[rsp->fwdata.supported_fec];

However, the range of values for rsp->fwdata.supported_fec is
0 to 3. Fix the if condition at line 967, accordingly.

Link: https://lore.kernel.org/lkml/[email-masked]/
Fixes: d0cf9503e908 ("octeontx2-pf: ethtool fec mode support")
Addresses-Coverity-ID: 1501722 ("Out-of-bounds read")
Suggested-by: Hariprasad Kelam <[email-masked]>
Signed-off-by: Gustavo A. R. Silva <[email-masked]>
---
Changes in v2:
 - Fix if condition.

 drivers/net/ethernet/marvell/octeontx2/nic/otx2_ethtool.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_ethtool.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_ethtool.c
index 237e5d3321d4..f4962a97a075 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_ethtool.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_ethtool.c
@@ -964,7 +964,7 @@ static int otx2_get_fecparam(struct net_device *netdev,
 	if (IS_ERR(rsp))
 		return PTR_ERR(rsp);
 
-	if (rsp->fwdata.supported_fec <= FEC_MAX_INDEX) {
+	if (rsp->fwdata.supported_fec < FEC_MAX_INDEX) {
 		if (!rsp->fwdata.supported_fec)
 			fecparam->fec = ETHTOOL_FEC_NONE;
 		else
-- 
2.27.0