| Message ID | 20210927112205.301876-2-vladimir.oltean@nxp.com |
|---|---|
| State | Accepted |
| Commit | fca315a38202960cfbb4c5a8f3ff5e0860e630cb |
| 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> > --- > arch/powerpc/cpu/mpc85xx/ether_fcc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/powerpc/cpu/mpc85xx/ether_fcc.c b/arch/powerpc/cpu/mpc85xx/ether_fcc.c > index 3c4eb1a7eba9..1f6f55707321 100644 > --- a/arch/powerpc/cpu/mpc85xx/ether_fcc.c > +++ b/arch/powerpc/cpu/mpc85xx/ether_fcc.c > @@ -444,7 +444,7 @@ int fec_initialize(struct bd_info *bis) > 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 = bb_miiphy_read; > mdiodev->write = bb_miiphy_write; > > -- > 2.25.1 > Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
diff --git a/arch/powerpc/cpu/mpc85xx/ether_fcc.c b/arch/powerpc/cpu/mpc85xx/ether_fcc.c index 3c4eb1a7eba9..1f6f55707321 100644 --- a/arch/powerpc/cpu/mpc85xx/ether_fcc.c +++ b/arch/powerpc/cpu/mpc85xx/ether_fcc.c @@ -444,7 +444,7 @@ int fec_initialize(struct bd_info *bis) 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 = bb_miiphy_read; mdiodev->write = bb_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> --- arch/powerpc/cpu/mpc85xx/ether_fcc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)