From: Vladimir Oltean Date: Mon, 27 Sep 2021 11:21:49 +0000 (+0300) Subject: net: mcdmafec: ensure bus->name is NULL terminated after MDIO_NAME_LEN truncation X-Git-Url: http://git.dujemihanovic.xyz/%22/img/sics.gif/%22/static/git-favicon.png?a=commitdiff_plain;h=e6324f438416304a7bf32245557cd24b53dc93d7;p=u-boot.git net: mcdmafec: ensure bus->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/fsl_mcdmafec.c b/drivers/net/fsl_mcdmafec.c index c20aef4ab2..e103f79305 100644 --- a/drivers/net/fsl_mcdmafec.c +++ b/drivers/net/fsl_mcdmafec.c @@ -541,7 +541,7 @@ static int mcdmafec_probe(struct udevice *dev) info->bus = mdio_alloc(); if (!info->bus) return -ENOMEM; - strncpy(info->bus->name, dev->name, MDIO_NAME_LEN); + strlcpy(info->bus->name, dev->name, MDIO_NAME_LEN); info->bus->read = mcffec_miiphy_read; info->bus->write = mcffec_miiphy_write;