[PATCH net-next 1/1] drivers/phylib: fix coverity issue

From: Piergiorgio Beruto
Date: Tue Jan 17 2023 - 17:50:01 EST


Coverity reported the following:

*** CID 1530573: (UNINIT)
drivers/net/phy/phy-c45.c:1036 in genphy_c45_plca_set_cfg()
1030 return ret;
1031
1032 val = ret;
1033 }
1034
1035 if (plca_cfg->node_cnt >= 0)
vvv CID 1530573: (UNINIT)
vvv Using uninitialized value "val".
1036 val = (val & ~MDIO_OATC14_PLCA_NCNT) |
1037 (plca_cfg->node_cnt << 8);
1038
1039 if (plca_cfg->node_id >= 0)
1040 val = (val & ~MDIO_OATC14_PLCA_ID) |
1041 (plca_cfg->node_id);
drivers/net/phy/phy-c45.c:1076 in genphy_c45_plca_set_cfg()
1070 return ret;
1071
1072 val = ret;
1073 }
1074
1075 if (plca_cfg->burst_cnt >= 0)
vvv CID 1530573: (UNINIT)
vvv Using uninitialized value "val".
1076 val = (val & ~MDIO_OATC14_PLCA_MAXBC) |
1077 (plca_cfg->burst_cnt << 8);
1078
1079 if (plca_cfg->burst_tmr >= 0)
1080 val = (val & ~MDIO_OATC14_PLCA_BTMR) |
1081 (plca_cfg->burst_tmr);

This is not actually creating a real problem because the path leading to
'val' being used uninitialized will eventually override the full content
of that variable before actually using it for writing the register.
However, the fix is simple and comes at basically no cost.

Signed-off-by: Piergiorgio Beruto <piergiorgio.beruto@xxxxxxxxx>
Reported-by: coverity-bot <keescook+coverity-bot@xxxxxxxxxxxx>
Addresses-Coverity-ID: 1530573 ("UNINIT")
Fixes: 493323416fed ("drivers/net/phy: add helpers to get/set PLCA configuration")
---
drivers/net/phy/phy-c45.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/phy/phy-c45.c b/drivers/net/phy/phy-c45.c
index cff83220595c..9f9565a4819d 100644
--- a/drivers/net/phy/phy-c45.c
+++ b/drivers/net/phy/phy-c45.c
@@ -999,8 +999,8 @@ EXPORT_SYMBOL_GPL(genphy_c45_plca_get_cfg);
int genphy_c45_plca_set_cfg(struct phy_device *phydev,
const struct phy_plca_cfg *plca_cfg)
{
+ u16 val = 0;
int ret;
- u16 val;

// PLCA IDVER is read-only
if (plca_cfg->version >= 0)
--
2.37.4