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authorChristoph Paasch <cpaasch@apple.com>2015-06-18 09:15:34 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-07-10 10:37:56 -0700
commit1df46092f1378c29d93eb78e7821821babe73158 (patch)
tree4ce2788e86c7fc8d91da36ac7394b07f7e69ce32 /net
parentf171360ae594c51a6bb01093b10f5742740e0c3d (diff)
tcp: Do not call tcp_fastopen_reset_cipher from interrupt context
[ Upstream commit dfea2aa654243f70dc53b8648d0bbdeec55a7df1 ] tcp_fastopen_reset_cipher really cannot be called from interrupt context. It allocates the tcp_fastopen_context with GFP_KERNEL and calls crypto_alloc_cipher, which allocates all kind of stuff with GFP_KERNEL. Thus, we might sleep when the key-generation is triggered by an incoming TFO cookie-request which would then happen in interrupt- context, as shown by enabling CONFIG_DEBUG_ATOMIC_SLEEP: [ 36.001813] BUG: sleeping function called from invalid context at mm/slub.c:1266 [ 36.003624] in_atomic(): 1, irqs_disabled(): 0, pid: 1016, name: packetdrill [ 36.004859] CPU: 1 PID: 1016 Comm: packetdrill Not tainted 4.1.0-rc7 #14 [ 36.006085] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 [ 36.008250] 00000000000004f2 ffff88007f8838a8 ffffffff8171d53a ffff880075a084a8 [ 36.009630] ffff880075a08000 ffff88007f8838c8 ffffffff810967d3 ffff88007f883928 [ 36.011076] 0000000000000000 ffff88007f8838f8 ffffffff81096892 ffff88007f89be00 [ 36.012494] Call Trace: [ 36.012953] <IRQ> [<ffffffff8171d53a>] dump_stack+0x4f/0x6d [ 36.014085] [<ffffffff810967d3>] ___might_sleep+0x103/0x170 [ 36.015117] [<ffffffff81096892>] __might_sleep+0x52/0x90 [ 36.016117] [<ffffffff8118e887>] kmem_cache_alloc_trace+0x47/0x190 [ 36.017266] [<ffffffff81680d82>] ? tcp_fastopen_reset_cipher+0x42/0x130 [ 36.018485] [<ffffffff81680d82>] tcp_fastopen_reset_cipher+0x42/0x130 [ 36.019679] [<ffffffff81680f01>] tcp_fastopen_init_key_once+0x61/0x70 [ 36.020884] [<ffffffff81680f2c>] __tcp_fastopen_cookie_gen+0x1c/0x60 [ 36.022058] [<ffffffff816814ff>] tcp_try_fastopen+0x58f/0x730 [ 36.023118] [<ffffffff81671788>] tcp_conn_request+0x3e8/0x7b0 [ 36.024185] [<ffffffff810e3872>] ? __module_text_address+0x12/0x60 [ 36.025327] [<ffffffff8167b2e1>] tcp_v4_conn_request+0x51/0x60 [ 36.026410] [<ffffffff816727e0>] tcp_rcv_state_process+0x190/0xda0 [ 36.027556] [<ffffffff81661f97>] ? __inet_lookup_established+0x47/0x170 [ 36.028784] [<ffffffff8167c2ad>] tcp_v4_do_rcv+0x16d/0x3d0 [ 36.029832] [<ffffffff812e6806>] ? security_sock_rcv_skb+0x16/0x20 [ 36.030936] [<ffffffff8167cc8a>] tcp_v4_rcv+0x77a/0x7b0 [ 36.031875] [<ffffffff816af8c3>] ? iptable_filter_hook+0x33/0x70 [ 36.032953] [<ffffffff81657d22>] ip_local_deliver_finish+0x92/0x1f0 [ 36.034065] [<ffffffff81657f1a>] ip_local_deliver+0x9a/0xb0 [ 36.035069] [<ffffffff81657c90>] ? ip_rcv+0x3d0/0x3d0 [ 36.035963] [<ffffffff81657569>] ip_rcv_finish+0x119/0x330 [ 36.036950] [<ffffffff81657ba7>] ip_rcv+0x2e7/0x3d0 [ 36.037847] [<ffffffff81610652>] __netif_receive_skb_core+0x552/0x930 [ 36.038994] [<ffffffff81610a57>] __netif_receive_skb+0x27/0x70 [ 36.040033] [<ffffffff81610b72>] process_backlog+0xd2/0x1f0 [ 36.041025] [<ffffffff81611482>] net_rx_action+0x122/0x310 [ 36.042007] [<ffffffff81076743>] __do_softirq+0x103/0x2f0 [ 36.042978] [<ffffffff81723e3c>] do_softirq_own_stack+0x1c/0x30 This patch moves the call to tcp_fastopen_init_key_once to the places where a listener socket creates its TFO-state, which always happens in user-context (either from the setsockopt, or implicitly during the listen()-call) Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Fixes: 222e83d2e0ae ("tcp: switch tcp_fastopen key generation to net_get_random_once") Signed-off-by: Christoph Paasch <cpaasch@apple.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/af_inet.c2
-rw-r--r--net/ipv4/tcp.c7
-rw-r--r--net/ipv4/tcp_fastopen.c2
3 files changed, 7 insertions, 4 deletions
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 07bd8edef417..951fe55b1671 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -228,6 +228,8 @@ int inet_listen(struct socket *sock, int backlog)
err = 0;
if (err)
goto out;
+
+ tcp_fastopen_init_key_once(true);
}
err = inet_csk_listen_start(sk, backlog);
if (err)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 29d240b87af1..dc45221dc692 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2684,10 +2684,13 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
case TCP_FASTOPEN:
if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE |
- TCPF_LISTEN)))
+ TCPF_LISTEN))) {
+ tcp_fastopen_init_key_once(true);
+
err = fastopen_init_queue(sk, val);
- else
+ } else {
err = -EINVAL;
+ }
break;
case TCP_TIMESTAMP:
if (!tp->repair)
diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c
index f195d9316e55..ee6518d1afe5 100644
--- a/net/ipv4/tcp_fastopen.c
+++ b/net/ipv4/tcp_fastopen.c
@@ -84,8 +84,6 @@ void tcp_fastopen_cookie_gen(__be32 src, __be32 dst,
__be32 path[4] = { src, dst, 0, 0 };
struct tcp_fastopen_context *ctx;
- tcp_fastopen_init_key_once(true);
-
rcu_read_lock();
ctx = rcu_dereference(tcp_fastopen_ctx);
if (ctx) {