From f5dbfc82a90b2333bfee76906df883ba86a85f56 Mon Sep 17 00:00:00 2001
From: Eugeniu Rosca <erosca@de.adit-jv.com>
Date: Thu, 4 Jan 2024 05:26:23 +0100
Subject: [PATCH] net: phy: Fix signed shift overflow
Booting R-Car Gen3 arm64 U-Boot with CONFIG_UBSAN=y resulted in:
=====================================================================
UBSAN: Undefined behaviour in drivers/net/phy/phy.c:728:19
left shift of 1 by 31 places cannot be represented in type 'int'
=====================================================================
Fix it by appending the UL suffix to the numeric literal. While at it,
convert the type of "addr" variable from signed to unsigned, to protect
against shifting the numeric literal by a negative value (which would
lead to yet another undefined behavior).
Fixes: 1adb406b0141 ("phy: add phy_find_by_mask/phy_connect_dev")
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
* Using U-suffix for integer is sufficient.
* ffs() of non-zero value cannot be 0. But addr being unsigned is
* preferable.
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
---
drivers/net/phy/phy.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 63b3e46f10..f39ca942f6 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -642,12 +642,12 @@ static struct phy_device *search_for_existing_phy(struct mii_dev *bus,
{
/* If we have one, return the existing device, with new interface */
while (phy_mask) {
- int addr = ffs(phy_mask) - 1;
+ unsigned int addr = ffs(phy_mask) - 1;
if (bus->phymap[addr])
return bus->phymap[addr];
- phy_mask &= ~(1 << addr);
+ phy_mask &= ~(1U << addr);
}
return NULL;
}
--
2.39.5