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authorEric Dumazet <eric.dumazet@gmail.com>2010-10-04 22:42:08 +0000
committerDavid S. Miller <davem@davemloft.net>2010-10-05 20:35:53 -0700
commit79315068f4560f3f7bd6e9790190dcb43059770c (patch)
treeda41cf961fd143ba9365fcb18a657dba904e617f /net/caif
parent27e6f065df132b5270014d3285889b15185e9da9 (diff)
downloadvexpress-lsk-79315068f4560f3f7bd6e9790190dcb43059770c.tar.gz
caif: fix two caif_connect() bugs
caif_connect() might dereference a netdevice after dev_put() it. It also doesnt check dev_get_by_index() return value and could dereference a NULL pointer. Fix it, using RCU to avoid taking a reference. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Sjur Braendeland <sjur.brandeland@stericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/caif')
-rw-r--r--net/caif/caif_socket.c21
1 files changed, 15 insertions, 6 deletions
diff --git a/net/caif/caif_socket.c b/net/caif/caif_socket.c
index 8ce90478611..4bf28f25f36 100644
--- a/net/caif/caif_socket.c
+++ b/net/caif/caif_socket.c
@@ -827,6 +827,7 @@ static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
long timeo;
int err;
int ifindex, headroom, tailroom;
+ unsigned int mtu;
struct net_device *dev;
lock_sock(sk);
@@ -896,15 +897,23 @@ static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
cf_sk->sk.sk_state = CAIF_DISCONNECTED;
goto out;
}
- dev = dev_get_by_index(sock_net(sk), ifindex);
+
+ err = -ENODEV;
+ rcu_read_lock();
+ dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
+ if (!dev) {
+ rcu_read_unlock();
+ goto out;
+ }
cf_sk->headroom = LL_RESERVED_SPACE_EXTRA(dev, headroom);
+ mtu = dev->mtu;
+ rcu_read_unlock();
+
cf_sk->tailroom = tailroom;
- cf_sk->maxframe = dev->mtu - (headroom + tailroom);
- dev_put(dev);
+ cf_sk->maxframe = mtu - (headroom + tailroom);
if (cf_sk->maxframe < 1) {
- pr_warning("CAIF: %s(): CAIF Interface MTU too small (%d)\n",
- __func__, dev->mtu);
- err = -ENODEV;
+ pr_warning("CAIF: %s(): CAIF Interface MTU too small (%u)\n",
+ __func__, mtu);
goto out;
}