kernel.git/net/dccp/ipv6.c, branch linux-3.18.y

dccp: do not use ipv6 header for ipv4 flow

2019-04-03T04:22:12Z

[ Upstream commit e0aa67709f89d08c8d8e5bdd9e0b649df61d0090 ] When a dual stack dccp listener accepts an ipv4 flow, it should not attempt to use an ipv6 header or inet6_iif() helper. Fixes: 3df80d9320bc ("[DCCP]: Introduce DCCPv6") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv6/dccp: do not inherit ipv6_mc_list from parent

2017-11-24T07:30:03Z

commit 83eaddab4378db256d00d295bda6ca997cd13a52 upstream. Like commit 657831ffc38e ("dccp/tcp: do not inherit mc_list from parent") we should clear ipv6_mc_list etc. for IPv6 sockets too. Cc: Eric Dumazet Signed-off-by: Cong Wang Acked-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Connor O'Brien [AmitP: cherry-picked this backported commit from android-3.18] Signed-off-by: Amit Pundir Signed-off-by: Greg Kroah-Hartman

dccp/tcp: fix routing redirect race

2017-04-18T05:55:54Z

commit 45caeaa5ac0b4b11784ac6f932c0ad4c6b67cda0 upstream. 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

ipv6: add complete rcu protection around np->opt

2015-12-14T17:19:26Z

[ Upstream commit 45f6fad84cc305103b28d73482b344d7f5b76f39 ] This patch addresses multiple problems : UDP/RAW sendmsg() need to get a stable struct ipv6_txoptions while socket is not locked : Other threads can change np->opt concurrently. Dmitry posted a syzkaller (http://github.com/google/syzkaller) program desmonstrating use-after-free. Starting with TCP/DCCP lockless listeners, tcp_v6_syn_recv_sock() and dccp_v6_request_recv_sock() also need to use RCU protection to dereference np->opt once (before calling ipv6_dup_options()) This patch adds full RCU protection to np->opt Reported-by: Dmitry Vyukov Signed-off-by: Eric Dumazet Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

ipv6: introduce tcp_v6_iif()

2014-10-18T03:48:07Z

Commit 971f10eca186 ("tcp: better TCP_SKB_CB layout to reduce cache line misses") added a regression for SO_BINDTODEVICE on IPv6. This is because we still use inet6_iif() which expects that IP6 control block is still at the beginning of skb->cb[] This patch adds tcp_v6_iif() helper and uses it where necessary. Because __inet6_lookup_skb() is used by TCP and DCCP, we add an iif parameter to it. Signed-off-by: Eric Dumazet Fixes: 971f10eca186 ("tcp: better TCP_SKB_CB layout to reduce cache line misses") Acked-by: Cong Wang Signed-off-by: David S. Miller

ipv6: add a struct inet6_skb_parm param to ipv6_opt_accepted()

2014-09-28T20:35:43Z

ipv6_opt_accepted() assumes IP6CB(skb) holds the struct inet6_skb_parm that it needs. Lets not assume this, as TCP stack might use a different place. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: remove inet6_reqsk_alloc

2014-06-27T22:53:35Z

Since pktops is only used for IPv6 only and opts is used for IPv4 only, we can move these fields into a union and this allows us to drop the inet6_reqsk_alloc function as after this change it becomes equivalent with inet_reqsk_alloc. This patch also fixes a kmemcheck issue in the IPv6 stack: the flags field was not annotated after a request_sock was allocated. Signed-off-by: Octavian Purdila Signed-off-by: David S. Miller

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next

2013-12-19T23:37:49Z

Steffen Klassert says: ==================== pull request (net-next): ipsec-next 2013-12-19 1) Use the user supplied policy index instead of a generated one if present. From Fan Du. 2) Make xfrm migration namespace aware. From Fan Du. 3) Make the xfrm state and policy locks namespace aware. From Fan Du. 4) Remove ancient sleeping when the SA is in acquire state, we now queue packets to the policy instead. This replaces the sleeping code. 5) Remove FLOWI_FLAG_CAN_SLEEP. This was used to notify xfrm about the posibility to sleep. The sleeping code is gone, so remove it. 6) Check user specified spi for IPComp. Thr spi for IPcomp is only 16 bit wide, so check for a valid value. From Fan Du. 7) Export verify_userspi_info to check for valid user supplied spi ranges with pfkey and netlink. From Fan Du. 8) RFC3173 states that if the total size of a compressed payload and the IPComp header is not smaller than the size of the original payload, the IP datagram must be sent in the original non-compressed form. These packets are dropped by the inbound policy check because they are not transformed. Document the need to set 'level use' for IPcomp to receive such packets anyway. From Fan Du. Please pull or let me know if there are problems. ==================== Signed-off-by: David S. Miller

ipv6: support IPV6_PMTU_INTERFACE on sockets

2013-12-18T22:37:05Z

IPV6_PMTU_INTERFACE is the same as IPV6_PMTU_PROBE for ipv6. Add it nontheless for symmetry with IPv4 sockets. Also drop incoming MTU information if this mode is enabled. The additional bit in ipv6_pinfo just eats in the padding behind the bitfield. There are no changes to the layout of the struct at all. Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller

ipv6: do not erase dst address with flow label destination

2013-12-11T03:51:00Z

This patch is following b579035ff766c9412e2b92abf5cab794bff102b6 "ipv6: remove old conditions on flow label sharing" Since there is no reason to restrict a label to a destination, we should not erase the destination value of a socket with the value contained in the flow label storage. This patch allows to really have the same flow label to more than one destination. Signed-off-by: Florent Fourcot Reviewed-by: Hannes Frederic Sowa Signed-off-by: David S. Miller