[PATCH 5.15 046/128] net: stmmac: ptp: fix potentially overflowing expression

[Greg Kroah-Hartman]

From: Xiaoliang Yang <xiaoliang.yang_1@xxxxxxx>

[ Upstream commit eccffcf4657ab9a148faaa0eb354d2a091caf552 ]

Convert the u32 variable to type u64 in a context where expression of
type u64 is required to avoid potential overflow.

Fixes: e9e3720002f6 ("net: stmmac: ptp: update tas basetime after ptp adjust")
Signed-off-by: Xiaoliang Yang <xiaoliang.yang_1@xxxxxxx>
Link: https://lore.kernel.org/r/20211223073928.37371-1-xiaoliang.yang_1@xxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
index 580cc035536bd..be9b58b2abf9b 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c
@@ -102,7 +102,7 @@ static int stmmac_adjust_time(struct ptp_clock_info *ptp, s64 delta)
 		time.tv_nsec = priv->plat->est->btr_reserve[0];
 		time.tv_sec = priv->plat->est->btr_reserve[1];
 		basetime = timespec64_to_ktime(time);
-		cycle_time = priv->plat->est->ctr[1] * NSEC_PER_SEC +
+		cycle_time = (u64)priv->plat->est->ctr[1] * NSEC_PER_SEC +
 			     priv->plat->est->ctr[0];
 		time = stmmac_calc_tas_basetime(basetime,
 						current_time_ns,
-- 
2.34.1