diff options
| author | Daniel Borkmann <dborkman@redhat.com> | 2013-06-12 16:02:27 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-06-13 01:38:36 -0700 |
| commit | 2dc85bf323515e59e15dfa858d1472bb25cad0fe (patch) | |
| tree | 48d2bb80d960a20a12ebb2b5108c3e589605e26b | |
| parent | 631f24a2febb228f82604dc5330091e8080cd8ae (diff) | |
packet: packet_getname_spkt: make sure string is always 0-terminated
uaddr->sa_data is exactly of size 14, which is hard-coded here and
passed as a size argument to strncpy(). A device name can be of size
IFNAMSIZ (== 16), meaning we might leave the destination string
unterminated. Thus, use strlcpy() and also sizeof() while we're
at it. We need to memset the data area beforehand, since strlcpy
does not padd the remaining buffer with zeroes for user space, so
that we do not possibly leak anything.
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/packet/af_packet.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 8ec1bca7f85..20a1bd0e654 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2851,12 +2851,11 @@ static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, return -EOPNOTSUPP; uaddr->sa_family = AF_PACKET; + memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data)); rcu_read_lock(); dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex); if (dev) - strncpy(uaddr->sa_data, dev->name, 14); - else - memset(uaddr->sa_data, 0, 14); + strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data)); rcu_read_unlock(); *uaddr_len = sizeof(*uaddr); |