From 977b53f0b30e833b3155c247f48014363f9cfcf0 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Mon, 27 Sep 2021 14:21:59 +0300 Subject: [PATCH] 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 Reviewed-by: Ramon Fried --- drivers/qe/uec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) 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; -- 2.39.5