diff options
Diffstat (limited to 'net/mctp')
| -rw-r--r-- | net/mctp/device.c | 21 | ||||
| -rw-r--r-- | net/mctp/route.c | 5 | ||||
| -rw-r--r-- | net/mctp/test/utils.c | 1 |
3 files changed, 22 insertions, 5 deletions
diff --git a/net/mctp/device.c b/net/mctp/device.c index 9e097e61f23a..b754c31162b1 100644 --- a/net/mctp/device.c +++ b/net/mctp/device.c @@ -25,12 +25,25 @@ struct mctp_dump_cb { size_t a_idx; }; -/* unlocked: caller must hold rcu_read_lock */ +/* unlocked: caller must hold rcu_read_lock. + * Returned mctp_dev has its refcount incremented, or NULL if unset. + */ struct mctp_dev *__mctp_dev_get(const struct net_device *dev) { - return rcu_dereference(dev->mctp_ptr); + struct mctp_dev *mdev = rcu_dereference(dev->mctp_ptr); + + /* RCU guarantees that any mdev is still live. + * Zero refcount implies a pending free, return NULL. + */ + if (mdev) + if (!refcount_inc_not_zero(&mdev->refs)) + return NULL; + return mdev; } +/* Returned mctp_dev does not have refcount incremented. The returned pointer + * remains live while rtnl_lock is held, as that prevents mctp_unregister() + */ struct mctp_dev *mctp_dev_get_rtnl(const struct net_device *dev) { return rtnl_dereference(dev->mctp_ptr); @@ -124,6 +137,7 @@ static int mctp_dump_addrinfo(struct sk_buff *skb, struct netlink_callback *cb) if (mdev) { rc = mctp_dump_dev_addrinfo(mdev, skb, cb); + mctp_dev_put(mdev); // Error indicates full buffer, this // callback will get retried. if (rc < 0) @@ -298,7 +312,7 @@ void mctp_dev_hold(struct mctp_dev *mdev) void mctp_dev_put(struct mctp_dev *mdev) { - if (refcount_dec_and_test(&mdev->refs)) { + if (mdev && refcount_dec_and_test(&mdev->refs)) { dev_put(mdev->dev); kfree_rcu(mdev, rcu); } @@ -370,6 +384,7 @@ static size_t mctp_get_link_af_size(const struct net_device *dev, if (!mdev) return 0; ret = nla_total_size(4); /* IFLA_MCTP_NET */ + mctp_dev_put(mdev); return ret; } diff --git a/net/mctp/route.c b/net/mctp/route.c index fe6c8bf1ec2c..6f277e56b168 100644 --- a/net/mctp/route.c +++ b/net/mctp/route.c @@ -836,7 +836,7 @@ int mctp_local_output(struct sock *sk, struct mctp_route *rt, { struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk); struct mctp_skb_cb *cb = mctp_cb(skb); - struct mctp_route tmp_rt; + struct mctp_route tmp_rt = {0}; struct mctp_sk_key *key; struct net_device *dev; struct mctp_hdr *hdr; @@ -948,6 +948,7 @@ out_release: mctp_route_release(rt); dev_put(dev); + mctp_dev_put(tmp_rt.dev); return rc; @@ -1124,11 +1125,13 @@ static int mctp_pkttype_receive(struct sk_buff *skb, struct net_device *dev, rt->output(rt, skb); mctp_route_release(rt); + mctp_dev_put(mdev); return NET_RX_SUCCESS; err_drop: kfree_skb(skb); + mctp_dev_put(mdev); return NET_RX_DROP; } diff --git a/net/mctp/test/utils.c b/net/mctp/test/utils.c index 7b7918702592..e03ba66bbe18 100644 --- a/net/mctp/test/utils.c +++ b/net/mctp/test/utils.c @@ -54,7 +54,6 @@ struct mctp_test_dev *mctp_test_create_dev(void) rcu_read_lock(); dev->mdev = __mctp_dev_get(ndev); - mctp_dev_hold(dev->mdev); rcu_read_unlock(); return dev; |