From: Vladimir Oltean Date: Mon, 27 Sep 2021 11:21:44 +0000 (+0300) Subject: net: at91_emac: ensure mdiodev->name is NULL terminated after MDIO_NAME_LEN truncation X-Git-Tag: v2025.01-rc5-pxa1908~1694^2~6^2~21 X-Git-Url: http://git.dujemihanovic.xyz/img/static/git-logo.png?a=commitdiff_plain;h=05b7cb5ef16fa47ae62305d1c882f3b7dcee5779;p=u-boot.git net: at91_emac: 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/at91_emac.c b/drivers/net/at91_emac.c index e40b94ad89..b4581d8c93 100644 --- a/drivers/net/at91_emac.c +++ b/drivers/net/at91_emac.c @@ -507,7 +507,7 @@ int at91emac_register(struct bd_info *bis, unsigned long iobase) struct mii_dev *mdiodev = mdio_alloc(); if (!mdiodev) return -ENOMEM; - strncpy(mdiodev->name, dev->name, MDIO_NAME_LEN); + strlcpy(mdiodev->name, dev->name, MDIO_NAME_LEN); mdiodev->read = at91emac_mii_read; mdiodev->write = at91emac_mii_write;