From 9789b697c6e4db733b4afe9572cd8e053c63e943 Mon Sep 17 00:00:00 2001 From: Lorenzo Colitti Date: Mon, 12 Dec 2016 11:41:11 +0900 Subject: Revert "net: core: Support UID-based routing." This reverts commit fd2cf795f3ab193752781be7372949ac1780d0ed. Bug: 16355602 Change-Id: I1ec2d1eb3d53f4186b60c6ca5d6a20fcca46d442 --- net/ipv6/tcp_ipv6.c | 1 - 1 file changed, 1 deletion(-) (limited to 'net/ipv6/tcp_ipv6.c') diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index e6b044480333..f6eb65a5d343 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -234,7 +234,6 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr, fl6.flowi6_mark = sk->sk_mark; fl6.fl6_dport = usin->sin6_port; fl6.fl6_sport = inet->inet_sport; - fl6.flowi6_uid = sock_i_uid(sk); opt = rcu_dereference_protected(np->opt, sock_owned_by_user(sk)); final_p = fl6_update_dst(&fl6, opt, &final); -- cgit v1.2.3 From 344afd627cca0223464079135926f611fdbb0574 Mon Sep 17 00:00:00 2001 From: Lorenzo Colitti Date: Fri, 4 Nov 2016 02:23:43 +0900 Subject: net: inet: Support UID-based routing in IP protocols. - Use the UID in routing lookups made by protocol connect() and sendmsg() functions. - Make sure that routing lookups triggered by incoming packets (e.g., Path MTU discovery) take the UID of the socket into account. - For packets not associated with a userspace socket, (e.g., ping replies) use UID 0 inside the user namespace corresponding to the network namespace the socket belongs to. This allows all namespaces to apply routing and iptables rules to kernel-originated traffic in that namespaces by matching UID 0. This is better than using the UID of the kernel socket that is sending the traffic, because the UID of kernel sockets created at namespace creation time (e.g., the per-processor ICMP and TCP sockets) is the UID of the user that created the socket, which might not be mapped in the namespace. Bug: 16355602 Change-Id: I910504b508948057912bc188fd1e8aca28294de3 Tested: compiles allnoconfig, allyesconfig, allmodconfig Tested: https://android-review.googlesource.com/253302 Signed-off-by: Lorenzo Colitti Signed-off-by: David S. Miller --- net/ipv6/tcp_ipv6.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'net/ipv6/tcp_ipv6.c') diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index f6eb65a5d343..1f5505ecf7f7 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -234,6 +234,7 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr, fl6.flowi6_mark = sk->sk_mark; fl6.fl6_dport = usin->sin6_port; fl6.fl6_sport = inet->inet_sport; + fl6.flowi6_uid = sk->sk_uid; opt = rcu_dereference_protected(np->opt, sock_owned_by_user(sk)); final_p = fl6_update_dst(&fl6, opt, &final); @@ -810,6 +811,7 @@ static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark); fl6.fl6_dport = t1->dest; fl6.fl6_sport = t1->source; + fl6.flowi6_uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL); security_skb_classify_flow(skb, flowi6_to_flowi(&fl6)); /* Pass a socket to ip6_dst_lookup either it is for RST -- cgit v1.2.3 From 4ab956b561334866dfe1b17d9c7567313e07cfa2 Mon Sep 17 00:00:00 2001 From: Jon Maxwell Date: Fri, 10 Mar 2017 16:40:33 +1100 Subject: dccp/tcp: fix routing redirect race MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit 45caeaa5ac0b4b11784ac6f932c0ad4c6b67cda0 ] As Eric Dumazet pointed out this also needs to be fixed in IPv6. v2: Contains the IPv6 tcp/Ipv6 dccp patches as well. We have seen a few incidents lately where a dst_enty has been freed with a dangling TCP socket reference (sk->sk_dst_cache) pointing to that dst_entry. If the conditions/timings are right a crash then ensues when the freed dst_entry is referenced later on. A Common crashing back trace is: #8 [] page_fault at ffffffff8163e648 [exception RIP: __tcp_ack_snd_check+74] . . #9 [] tcp_rcv_established at ffffffff81580b64 #10 [] tcp_v4_do_rcv at ffffffff8158b54a #11 [] tcp_v4_rcv at ffffffff8158cd02 #12 [] ip_local_deliver_finish at ffffffff815668f4 #13 [] ip_local_deliver at ffffffff81566bd9 #14 [] ip_rcv_finish at ffffffff8156656d #15 [] ip_rcv at ffffffff81566f06 #16 [] __netif_receive_skb_core at ffffffff8152b3a2 #17 [] __netif_receive_skb at ffffffff8152b608 #18 [] netif_receive_skb at ffffffff8152b690 #19 [] vmxnet3_rq_rx_complete at ffffffffa015eeaf [vmxnet3] #20 [] vmxnet3_poll_rx_only at ffffffffa015f32a [vmxnet3] #21 [] net_rx_action at ffffffff8152bac2 #22 [] __do_softirq at ffffffff81084b4f #23 [] call_softirq at ffffffff8164845c #24 [] do_softirq at ffffffff81016fc5 #25 [] irq_exit at ffffffff81084ee5 #26 [] do_IRQ at ffffffff81648ff8 Of course it may happen with other NIC drivers as well. It's found the freed dst_entry here: 224 static bool tcp_in_quickack_mode(struct sock *sk)↩ 225 {↩ 226 ▹ const struct inet_connection_sock *icsk = inet_csk(sk);↩ 227 ▹ const struct dst_entry *dst = __sk_dst_get(sk);↩ 228 ↩ 229 ▹ return (dst && dst_metric(dst, RTAX_QUICKACK)) ||↩ 230 ▹ ▹ (icsk->icsk_ack.quick && !icsk->icsk_ack.pingpong);↩ 231 }↩ But there are other backtraces attributed to the same freed dst_entry in netfilter code as well. All the vmcores showed 2 significant clues: - Remote hosts behind the default gateway had always been redirected to a different gateway. A rtable/dst_entry will be added for that host. Making more dst_entrys with lower reference counts. Making this more probable. - All vmcores showed a postitive LockDroppedIcmps value, e.g: LockDroppedIcmps 267 A closer look at the tcp_v4_err() handler revealed that do_redirect() will run regardless of whether user space has the socket locked. This can result in a race condition where the same dst_entry cached in sk->sk_dst_entry can be decremented twice for the same socket via: do_redirect()->__sk_dst_check()-> dst_release(). Which leads to the dst_entry being prematurely freed with another socket pointing to it via sk->sk_dst_cache and a subsequent crash. To fix this skip do_redirect() if usespace has the socket locked. Instead let the redirect take place later when user space does not have the socket locked. The dccp/IPv6 code is very similar in this respect, so fixing it there too. As Eric Garver pointed out the following commit now invalidates routes. Which can set the dst->obsolete flag so that ipv4_dst_check() returns null and triggers the dst_release(). Fixes: ceb3320610d6 ("ipv4: Kill routes during PMTU/redirect updates.") Cc: Eric Garver Cc: Hannes Sowa Signed-off-by: Jon Maxwell Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv6/tcp_ipv6.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'net/ipv6/tcp_ipv6.c') diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 76a8c8057a23..1a63c4deef26 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -376,10 +376,12 @@ static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, np = inet6_sk(sk); if (type == NDISC_REDIRECT) { - struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie); + if (!sock_owned_by_user(sk)) { + struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie); - if (dst) - dst->ops->redirect(dst, sk, skb); + if (dst) + dst->ops->redirect(dst, sk, skb); + } goto out; } -- cgit v1.2.3