net: qe: uec: ensure mdiodev->name is NULL terminated after MDIO_NAME_LEN truncation
authorVladimir Oltean <vladimir.oltean@nxp.com>
Mon, 27 Sep 2021 11:21:59 +0000 (14:21 +0300)
committerRamon Fried <rfried.dev@gmail.com>
Tue, 28 Sep 2021 15:50:56 +0000 (18:50 +0300)
commit977b53f0b30e833b3155c247f48014363f9cfcf0
treeaa110dec1554c53089ac5065e4ee43a2f61d3fbd
parentfe04172479c344dcdbf566c6d7624d72720fe410
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>
drivers/qe/uec.c