GitHub-Mirror/Star64_linux
2
0
Fork 0
mirror of https://github.com/Fishwaldo/Star64_linux.git synced 2025-07-23 07:12:09 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

inet_diag: fix access to tcp cc information

Browse source 
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 <edumazet@google.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2015-04-16 18:10:35 -07:00 • committed by David S. Miller
parent fad9dfefea
commit 521f1cf1db
7 changed files with 36 additions and 18 deletions
Download patch file Download diff file Expand all files Collapse all files

28
net/ipv4/inet_diag.c
View file

@ -111,6 +111,7 @@ int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
const struct nlmsghdr *unlh)
{
const struct inet_sock *inet = inet_sk(sk);
const struct tcp_congestion_ops *ca_ops;
const struct inet_diag_handler *handler;
int ext = req->idiag_ext;
struct inet_diag_msg *r;
@ -208,16 +209,31 @@ int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
info = nla_data(attr);
}
if ((ext & (1 << (INET_DIAG_CONG - 1))) && icsk->icsk_ca_ops)
if (nla_put_string(skb, INET_DIAG_CONG,
icsk->icsk_ca_ops->name) < 0)
if (ext & (1 << (INET_DIAG_CONG - 1))) {
int err = 0;
rcu_read_lock();
ca_ops = READ_ONCE(icsk->icsk_ca_ops);
if (ca_ops)
err = nla_put_string(skb, INET_DIAG_CONG, ca_ops->name);
rcu_read_unlock();
if (err < 0)
goto errout;
}
handler->idiag_get_info(sk, r, info);
if (sk->sk_state < TCP_TIME_WAIT &&
icsk->icsk_ca_ops && icsk->icsk_ca_ops->get_info)
icsk->icsk_ca_ops->get_info(sk, ext, skb);
if (sk->sk_state < TCP_TIME_WAIT) {
int err = 0;
rcu_read_lock();
ca_ops = READ_ONCE(icsk->icsk_ca_ops);
if (ca_ops && ca_ops->get_info)
err = ca_ops->get_info(sk, ext, skb);
rcu_read_unlock();
if (err < 0)
goto errout;
}
out:
nlmsg_end(skb, nlh);