| Message ID | 20210927112205.301876-6-vladimir.oltean@nxp.com |
|---|---|
| State | Accepted |
| Commit | 5f1d1a194008d4dee8a7ed3783433062999e4678 |
| Delegated to: | Ramon Fried |
| Headers | show |
| Series | Fix some non-NULL terminated strings in the networking subsystem | expand |
On Mon, Sep 27, 2021 at 2:22 PM Vladimir Oltean <vladimir.oltean@nxp.com> wrote: > > 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> > --- > drivers/net/bcm-sf2-eth.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/bcm-sf2-eth.c b/drivers/net/bcm-sf2-eth.c > index c862c141461c..88dc3ab38466 100644 > --- a/drivers/net/bcm-sf2-eth.c > +++ b/drivers/net/bcm-sf2-eth.c > @@ -250,7 +250,7 @@ int bcm_sf2_eth_register(struct bd_info *bis, u8 dev_num) > > if (!mdiodev) > return -ENOMEM; > - strncpy(mdiodev->name, dev->name, MDIO_NAME_LEN); > + strlcpy(mdiodev->name, dev->name, MDIO_NAME_LEN); > mdiodev->read = eth->miiphy_read; > mdiodev->write = eth->miiphy_write; > > -- > 2.25.1 > Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
diff --git a/drivers/net/bcm-sf2-eth.c b/drivers/net/bcm-sf2-eth.c index c862c141461c..88dc3ab38466 100644 --- a/drivers/net/bcm-sf2-eth.c +++ b/drivers/net/bcm-sf2-eth.c @@ -250,7 +250,7 @@ int bcm_sf2_eth_register(struct bd_info *bis, u8 dev_num) if (!mdiodev) return -ENOMEM; - strncpy(mdiodev->name, dev->name, MDIO_NAME_LEN); + strlcpy(mdiodev->name, dev->name, MDIO_NAME_LEN); mdiodev->read = eth->miiphy_read; mdiodev->write = eth->miiphy_write;
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> --- drivers/net/bcm-sf2-eth.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)