From: Vladimir Oltean Date: Mon, 27 Sep 2021 11:21:47 +0000 (+0300) Subject: net: ep93xx: ensure mdiodev->name is NULL terminated after MDIO_NAME_LEN truncation X-Git-Url: http://git.dujemihanovic.xyz/img/sics.gif?a=commitdiff_plain;h=9be5fa4d5766cb18e533ac6754879847d1e7a9ea;p=u-boot.git net: ep93xx: 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 Reviewed-by: Ramon Fried --- diff --git a/drivers/net/ep93xx_eth.c b/drivers/net/ep93xx_eth.c index 0218349b04..9f8df7de06 100644 --- a/drivers/net/ep93xx_eth.c +++ b/drivers/net/ep93xx_eth.c @@ -427,7 +427,7 @@ int ep93xx_miiphy_initialize(struct bd_info * const bd) struct mii_dev *mdiodev = mdio_alloc(); if (!mdiodev) return -ENOMEM; - strncpy(mdiodev->name, "ep93xx_eth0", MDIO_NAME_LEN); + strlcpy(mdiodev->name, "ep93xx_eth0", MDIO_NAME_LEN); mdiodev->read = ep93xx_miiphy_read; mdiodev->write = ep93xx_miiphy_write;