From: Vladimir Oltean <vladimir.oltean@nxp.com>
Date: Mon, 27 Sep 2021 11:21:59 +0000 (+0300)
Subject: net: qe: uec: ensure mdiodev->name is NULL terminated after MDIO_NAME_LEN truncation
X-Git-Tag: v2025.01-rc5-pxa1908~1694^2~6^2~6
X-Git-Url: http://git.dujemihanovic.xyz/html/index.html?a=commitdiff_plain;h=977b53f0b30e833b3155c247f48014363f9cfcf0;p=u-boot.git

net: qe: uec: ensure mdiodev->name is NULL terminated after MDIO_NAME_LEN truncation

strncpy() simply bails out when copying a source string whose size
exceeds the destination string size, potentially leaving the destination
string unterminated.

One possible way to address is to pass MDIO_NAME_LEN - 1 and a
previously zero-initialized destination string, but this is more
difficult to maintain.

The chosen alternative is to use strlcpy(), which properly limits the
copy len in the (srclen >= size) case to "size - 1", and which is also
more efficient than the strncpy() byte-by-byte implementation by using
memcpy. The destination string returned by strlcpy() is always NULL
terminated.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
---

diff --git a/drivers/qe/uec.c b/drivers/qe/uec.c
index 5da971ddc0..c4bd5c4a14 100644
--- a/drivers/qe/uec.c
+++ b/drivers/qe/uec.c
@@ -1407,7 +1407,7 @@ int uec_initialize(struct bd_info *bis, struct uec_inf *uec_info)
 
 	if (!mdiodev)
 		return -ENOMEM;
-	strncpy(mdiodev->name, dev->name, MDIO_NAME_LEN);
+	strlcpy(mdiodev->name, dev->name, MDIO_NAME_LEN);
 	mdiodev->read = uec_miiphy_read;
 	mdiodev->write = uec_miiphy_write;