net: phy: micrel: Use strlcpy() for ethtool::get_strings

ffainelli · davem330 · commit 55f53567afe5 · 2018-03-06T11:12:39.000-05:00
Our statistics strings are allocated at initialization without being bound to a specific size, yet, we would copy ETH_GSTRING_LEN bytes using memcpy() which would create out of bounds accesses, this was flagged by KASAN. Replace this with strlcpy() to make sure we are bound the source buffer size and we also always NUL-terminate strings. Fixes: 2b2427d ("phy: micrel: Add ethtool statistics counters") Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
@@ -664,8 +664,8 @@ static void kszphy_get_strings(struct phy_device *phydev, u8 *data)
 	int i;
 
 	for (i = 0; i < ARRAY_SIZE(kszphy_hw_stats); i++) {
-		memcpy(data + i * ETH_GSTRING_LEN,
-		       kszphy_hw_stats[i].string, ETH_GSTRING_LEN);
+		strlcpy(data + i * ETH_GSTRING_LEN,
+			kszphy_hw_stats[i].string, ETH_GSTRING_LEN);
 	}
 }
 

Original file line number	Diff line number	Diff line change
`@@ -664,8 +664,8 @@ static void kszphy_get_strings(struct phy_device phydev, u8 data)`
`664`	`664`	`int i;`
`665`	`665`
`666`	`666`	`for (i = 0; i < ARRAY_SIZE(kszphy_hw_stats); i++) {`
`667`		`- memcpy(data + i * ETH_GSTRING_LEN,`
`668`		`- kszphy_hw_stats[i].string, ETH_GSTRING_LEN);`
	`667`	`+ strlcpy(data + i * ETH_GSTRING_LEN,`
	`668`	`+ kszphy_hw_stats[i].string, ETH_GSTRING_LEN);`
`669`	`669`	`}`
`670`	`670`	`}`
`671`	`671`