path: root/include
diff options
authorEric Dumazet <edumazet@google.com>2019-07-18 19:28:14 -0700
committerDavid S. Miller <davem@davemloft.net>2019-07-18 20:33:48 -0700
commit8d650cdedaabb33e85e9b7c517c0c71fcecc1de9 (patch)
treeab0428e5e973eb2b4e8b1f4859a508e2c0d07859 /include
parentag71xx: fix return value check in ag71xx_probe() (diff)
tcp: fix tcp_set_congestion_control() use from bpf hook
Neal reported incorrect use of ns_capable() from bpf hook. bpf_setsockopt(...TCP_CONGESTION...) -> tcp_set_congestion_control() -> ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) -> ns_capable_common() -> current_cred() -> rcu_dereference_protected(current->cred, 1) Accessing 'current' in bpf context makes no sense, since packets are processed from softirq context. As Neal stated : The capability check in tcp_set_congestion_control() was written assuming a system call context, and then was reused from a BPF call site. The fix is to add a new parameter to tcp_set_congestion_control(), so that the ns_capable() call is only performed under the right context. Fixes: 91b5b21c7c16 ("bpf: Add support for changing congestion control") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Lawrence Brakmo <brakmo@fb.com> Reported-by: Neal Cardwell <ncardwell@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Acked-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
1 files changed, 2 insertions, 1 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h
index cca3c59b98bf..f42d300f0cfa 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1064,7 +1064,8 @@ void tcp_get_default_congestion_control(struct net *net, char *name);
void tcp_get_available_congestion_control(char *buf, size_t len);
void tcp_get_allowed_congestion_control(char *buf, size_t len);
int tcp_set_allowed_congestion_control(char *allowed);
-int tcp_set_congestion_control(struct sock *sk, const char *name, bool load, bool reinit);
+int tcp_set_congestion_control(struct sock *sk, const char *name, bool load,
+ bool reinit, bool cap_net_admin);
u32 tcp_slow_start(struct tcp_sock *tp, u32 acked);
void tcp_cong_avoid_ai(struct tcp_sock *tp, u32 w, u32 acked);