[PATCH AUTOSEL 5.6 071/129] net: stmmac: dwmac1000: fix out-of-bounds mac address reg setting

Sasha Levin
2020-04-15T11:41:59Z

From: Jisheng Zhang <Jisheng.Zhang@synaptics.com>

[ Upstream commit 3e1221acf6a8f8595b5ce354bab4327a69d54d18 ]

Commit 9463c4455900 ("net: stmmac: dwmac1000: Clear unused address
entries") cleared the unused mac address entries, but introduced an
out-of bounds mac address register programming bug -- After setting
the secondary unicast mac addresses, the "reg" value has reached
netdev_uc_count() + 1, thus we should only clear address entries
if (addr < perfect_addr_number)

Fixes: 9463c4455900 ("net: stmmac: dwmac1000: Clear unused address entries")
Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
index 542784300620f..efc6ec1b8027c 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
@@ -207,7 +207,7 @@ static void dwmac1000_set_filter(struct mac_device_info *hw,
reg++;
}

- while (reg <= perfect_addr_number) {
+ while (reg < perfect_addr_number) {
writel(0, ioaddr + GMAC_ADDR_HIGH(reg));
writel(0, ioaddr + GMAC_ADDR_LOW(reg));
reg++;
--
2.20.1