diff options
| author | Eric Dumazet <edumazet@google.com> | 2015-04-17 03:10:35 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-04-17 19:28:31 +0200 |
| commit | 521f1cf1dbb9d5ad858dca5dc75d1b45f64b6589 (patch) | |
| tree | 2c6276958f5d7348616d887f4a64f5b78ec6b9ef /net/ipv4/tcp_dctcp.c | |
| parent | tcp: tcp_get_info() should fetch socket fields once (diff) | |
| download | linux-521f1cf1dbb9d5ad858dca5dc75d1b45f64b6589.tar.xz linux-521f1cf1dbb9d5ad858dca5dc75d1b45f64b6589.zip | |
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 <edumazet@google.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_dctcp.c')
| -rw-r--r-- | net/ipv4/tcp_dctcp.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/net/ipv4/tcp_dctcp.c b/net/ipv4/tcp_dctcp.c index b504371af742..4376016f7fa5 100644 --- a/net/ipv4/tcp_dctcp.c +++ b/net/ipv4/tcp_dctcp.c @@ -277,7 +277,7 @@ static void dctcp_cwnd_event(struct sock *sk, enum tcp_ca_event ev) } } -static void dctcp_get_info(struct sock *sk, u32 ext, struct sk_buff *skb) +static int dctcp_get_info(struct sock *sk, u32 ext, struct sk_buff *skb) { const struct dctcp *ca = inet_csk_ca(sk); @@ -297,8 +297,9 @@ static void dctcp_get_info(struct sock *sk, u32 ext, struct sk_buff *skb) info.dctcp_ab_tot = ca->acked_bytes_total; } - nla_put(skb, INET_DIAG_DCTCPINFO, sizeof(info), &info); + return nla_put(skb, INET_DIAG_DCTCPINFO, sizeof(info), &info); } + return 0; } static struct tcp_congestion_ops dctcp __read_mostly = { |