From 521f1cf1dbb9d5ad858dca5dc75d1b45f64b6589 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 16 Apr 2015 18:10:35 -0700 Subject: inet_diag: fix access to tcp cc information Two different problems are fixed here : 1) inet_sk_diag_fill() might be called without socket lock held. icsk->icsk_ca_ops can change under us and module be unloaded. -> Access to freed memory. Fix this using rcu_read_lock() to prevent module unload. 2) Some TCP Congestion Control modules provide information but again this is not safe against icsk->icsk_ca_ops change and nla_put() errors were ignored. Some sockets could not get the additional info if skb was almost full. Fix this by returning a status from get_info() handlers and using rcu protection as well. Signed-off-by: Eric Dumazet Acked-by: Daniel Borkmann Signed-off-by: David S. Miller --- include/net/tcp.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/net') diff --git a/include/net/tcp.h b/include/net/tcp.h index 9598871485ce..051dc5c2802d 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -829,7 +829,7 @@ struct tcp_congestion_ops { /* hook for packet ack accounting (optional) */ void (*pkts_acked)(struct sock *sk, u32 num_acked, s32 rtt_us); /* get info for inet_diag (optional) */ - void (*get_info)(struct sock *sk, u32 ext, struct sk_buff *skb); + int (*get_info)(struct sock *sk, u32 ext, struct sk_buff *skb); char name[TCP_CA_NAME_MAX]; struct module *owner; -- cgit v1.2.3