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2019-11-23sctp: cache netns in sctp_ep_commonXin Long
This patch is to fix a data-race reported by syzbot: BUG: KCSAN: data-race in sctp_assoc_migrate / sctp_hash_obj write to 0xffff8880b67c0020 of 8 bytes by task 18908 on cpu 1: sctp_assoc_migrate+0x1a6/0x290 net/sctp/associola.c:1091 sctp_sock_migrate+0x8aa/0x9b0 net/sctp/socket.c:9465 sctp_accept+0x3c8/0x470 net/sctp/socket.c:4916 inet_accept+0x7f/0x360 net/ipv4/af_inet.c:734 __sys_accept4+0x224/0x430 net/socket.c:1754 __do_sys_accept net/socket.c:1795 [inline] __se_sys_accept net/socket.c:1792 [inline] __x64_sys_accept+0x4e/0x60 net/socket.c:1792 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff8880b67c0020 of 8 bytes by task 12003 on cpu 0: sctp_hash_obj+0x4f/0x2d0 net/sctp/input.c:894 rht_key_get_hash include/linux/rhashtable.h:133 [inline] rht_key_hashfn include/linux/rhashtable.h:159 [inline] rht_head_hashfn include/linux/rhashtable.h:174 [inline] head_hashfn lib/rhashtable.c:41 [inline] rhashtable_rehash_one lib/rhashtable.c:245 [inline] rhashtable_rehash_chain lib/rhashtable.c:276 [inline] rhashtable_rehash_table lib/rhashtable.c:316 [inline] rht_deferred_worker+0x468/0xab0 lib/rhashtable.c:420 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269 worker_thread+0xa0/0x800 kernel/workqueue.c:2415 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352 It was caused by rhashtable access asoc->base.sk when sctp_assoc_migrate is changing its value. However, what rhashtable wants is netns from asoc base.sk, and for an asoc, its netns won't change once set. So we can simply fix it by caching netns since created. Fixes: d6c0256a60e6 ("sctp: add the rhashtable apis for sctp global transport hashtable") Reported-by: syzbot+e3b35fe7918ff0ee474e@syzkaller.appspotmail.com Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-10-09net: silence KCSAN warnings around sk_add_backlog() callsEric Dumazet
sk_add_backlog() callers usually read sk->sk_rcvbuf without owning the socket lock. This means sk_rcvbuf value can be changed by other cpus, and KCSAN complains. Add READ_ONCE() annotations to document the lockless nature of these reads. Note that writes over sk_rcvbuf should also use WRITE_ONCE(), but this will be done in separate patches to ease stable backports (if we decide this is relevant for stable trees). BUG: KCSAN: data-race in tcp_add_backlog / tcp_recvmsg write to 0xffff88812ab369f8 of 8 bytes by interrupt on cpu 1: __sk_add_backlog include/net/sock.h:902 [inline] sk_add_backlog include/net/sock.h:933 [inline] tcp_add_backlog+0x45a/0xcc0 net/ipv4/tcp_ipv4.c:1737 tcp_v4_rcv+0x1aba/0x1bf0 net/ipv4/tcp_ipv4.c:1925 ip_protocol_deliver_rcu+0x51/0x470 net/ipv4/ip_input.c:204 ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:442 [inline] ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5004 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5118 netif_receive_skb_internal+0x59/0x190 net/core/dev.c:5208 napi_skb_finish net/core/dev.c:5671 [inline] napi_gro_receive+0x28f/0x330 net/core/dev.c:5704 receive_buf+0x284/0x30b0 drivers/net/virtio_net.c:1061 virtnet_receive drivers/net/virtio_net.c:1323 [inline] virtnet_poll+0x436/0x7d0 drivers/net/virtio_net.c:1428 napi_poll net/core/dev.c:6352 [inline] net_rx_action+0x3ae/0xa50 net/core/dev.c:6418 read to 0xffff88812ab369f8 of 8 bytes by task 7271 on cpu 0: tcp_recvmsg+0x470/0x1a30 net/ipv4/tcp.c:2047 inet_recvmsg+0xbb/0x250 net/ipv4/af_inet.c:838 sock_recvmsg_nosec net/socket.c:871 [inline] sock_recvmsg net/socket.c:889 [inline] sock_recvmsg+0x92/0xb0 net/socket.c:885 sock_read_iter+0x15f/0x1e0 net/socket.c:967 call_read_iter include/linux/fs.h:1864 [inline] new_sync_read+0x389/0x4f0 fs/read_write.c:414 __vfs_read+0xb1/0xc0 fs/read_write.c:427 vfs_read fs/read_write.c:461 [inline] vfs_read+0x143/0x2c0 fs/read_write.c:446 ksys_read+0xd5/0x1b0 fs/read_write.c:587 __do_sys_read fs/read_write.c:597 [inline] __se_sys_read fs/read_write.c:595 [inline] __x64_sys_read+0x4c/0x60 fs/read_write.c:595 do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 7271 Comm: syz-fuzzer Not tainted 5.3.0+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-10-09sctp: add chunks to sk_backlog when the newsk sk_socket is not setXin Long
This patch is to fix a NULL-ptr deref in selinux_socket_connect_helper: [...] kasan: GPF could be caused by NULL-ptr deref or user memory access [...] RIP: 0010:selinux_socket_connect_helper+0x94/0x460 [...] Call Trace: [...] selinux_sctp_bind_connect+0x16a/0x1d0 [...] security_sctp_bind_connect+0x58/0x90 [...] sctp_process_asconf+0xa52/0xfd0 [sctp] [...] sctp_sf_do_asconf+0x785/0x980 [sctp] [...] sctp_do_sm+0x175/0x5a0 [sctp] [...] sctp_assoc_bh_rcv+0x285/0x5b0 [sctp] [...] sctp_backlog_rcv+0x482/0x910 [sctp] [...] __release_sock+0x11e/0x310 [...] release_sock+0x4f/0x180 [...] sctp_accept+0x3f9/0x5a0 [sctp] [...] inet_accept+0xe7/0x720 It was caused by that the 'newsk' sk_socket was not set before going to security sctp hook when processing asconf chunk with SCTP_PARAM_ADD_IP or SCTP_PARAM_SET_PRIMARY: inet_accept()-> sctp_accept(): lock_sock(): lock listening 'sk' do_softirq(): sctp_rcv(): <-- [1] asconf chunk arrives and enqueued in 'sk' backlog sctp_sock_migrate(): set asoc's sk to 'newsk' release_sock(): sctp_backlog_rcv(): lock 'newsk' sctp_process_asconf() <-- [2] unlock 'newsk' sock_graft(): set sk_socket <-- [3] As it shows, at [1] the asconf chunk would be put into the listening 'sk' backlog, as accept() was holding its sock lock. Then at [2] asconf would get processed with 'newsk' as asoc's sk had been set to 'newsk'. However, 'newsk' sk_socket is not set until [3], while selinux_sctp_bind_connect() would deref it, then kernel crashed. Here to fix it by adding the chunk to sk_backlog until newsk sk_socket is set when .accept() is done. Note that sk->sk_socket can be NULL when the sock is closed, so SOCK_DEAD flag is also needed to check in sctp_newsk_ready(). Thanks to Ondrej for reviewing the code. Fixes: d452930fd3b9 ("selinux: Add SCTP support") Reported-by: Ying Xu <yinxu@redhat.com> Suggested-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-10-01netfilter: drop bridge nf reset from nf_resetFlorian Westphal
commit 174e23810cd31 ("sk_buff: drop all skb extensions on free and skb scrubbing") made napi recycle always drop skb extensions. The additional skb_ext_del() that is performed via nf_reset on napi skb recycle is not needed anymore. Most nf_reset() calls in the stack are there so queued skb won't block 'rmmod nf_conntrack' indefinitely. This removes the skb_ext_del from nf_reset, and renames it to a more fitting nf_reset_ct(). In a few selected places, add a call to skb_ext_reset to make sure that no active extensions remain. I am submitting this for "net", because we're still early in the release cycle. The patch applies to net-next too, but I think the rename causes needless divergence between those trees. Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-05-24treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 104Thomas Gleixner
Based on 1 normalized pattern(s): this sctp implementation is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 or at your option any later version this sctp implementation is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with gnu cc see the file copying if not see http www gnu org licenses extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 42 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190523091649.683323110@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-12sctp: add sock_reuseport for the sock in __sctp_hash_endpointXin Long
This is a part of sk_reuseport support for sctp. It defines a helper sctp_bind_addrs_check() to check if the bind_addrs in two socks are matched. It will add sock_reuseport if they are completely matched, and return err if they are partly matched, and alloc sock_reuseport if all socks are not matched at all. It will work until sk_reuseport support is added in sctp_get_port_local() in the next patch. v1->v2: - use 'laddr->valid && laddr2->valid' check instead as Marcelo pointed in sctp_bind_addrs_check(). Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-12sctp: do reuseport_select_sock in __sctp_rcv_lookup_endpointXin Long
This is a part of sk_reuseport support for sctp, and it selects a sock by the hashkey of lport, paddr and dport by default. It will work until sk_reuseport support is added in sctp_get_port_local() in the next patch. v1->v2: - define lport as __be16 instead of __be32 as Marcelo pointed in __sctp_rcv_lookup_endpoint(). Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-08net: Convert protocol error handlers from void to intStefano Brivio
We'll need this to handle ICMP errors for tunnels without a sending socket (i.e. FoU and GUE). There, we might have to look up different types of IP tunnels, registered as network protocols, before we get a match, so we want this for the error handlers of IPPROTO_IPIP and IPPROTO_IPV6 in both inet_protos and inet6_protos. These error codes will be used in the next patch. For consistency, return sensible error codes in protocol error handlers whenever handlers can't handle errors because, even if valid, they don't match a protocol or any of its states. This has no effect on existing error handling paths. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-15sctp: use the pmtu from the icmp packet to update transport pathmtuXin Long
Other than asoc pmtu sync from all transports, sctp_assoc_sync_pmtu is also processing transport pmtu_pending by icmp packets. But it's meaningless to use sctp_dst_mtu(t->dst) as new pmtu for a transport. The right pmtu value should come from the icmp packet, and it would be saved into transport->mtu_info in this patch and used later when the pmtu sync happens in sctp_sendmsg_to_asoc or sctp_packet_config. Besides, without this patch, as pmtu can only be updated correctly when receiving a icmp packet and no place is holding sock lock, it will take long time if the sock is busy with sending packets. Note that it doesn't process transport->mtu_info in .release_cb(), as there is no enough information for pmtu update, like for which asoc or transport. It is not worth traversing all asocs to check pmtu_pending. So unlike tcp, sctp does this in tx path, for which mtu_info needs to be atomic_t. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-22rhashtable: split rhashtable.hNeilBrown
Due to the use of rhashtables in net namespaces, rhashtable.h is included in lots of the kernel, so a small changes can required a large recompilation. This makes development painful. This patch splits out rhashtable-types.h which just includes the major type declarations, and does not include (non-trivial) inline code. rhashtable.h is no longer included by anything in the include/ directory. Common include files only include rhashtable-types.h so a large recompilation is only triggered when that changes. Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-27sctp: remove unnecessary asoc in sctp_has_associationXin Long
After Commit dae399d7fdee ("sctp: hold transport instead of assoc when lookup assoc in rx path"), it put transport instead of asoc in sctp_has_association. Variable 'asoc' is not used any more. So this patch is to remove it, while at it, it also changes the return type of sctp_has_association to bool, and does the same for it's caller sctp_endpoint_is_peeled_off. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-09net: use skb_is_gso_sctp() instead of open-codingDaniel Axtens
As well as the basic conversion, I noticed that a lot of the SCTP code checks gso_type without first checking skb_is_gso() so I have added that where appropriate. Also, document the helper. Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-12sctp: do not pr_err for the duplicated node in transport rhlistXin Long
The pr_err in sctp_hash_transport was supposed to report a sctp bug for using rhashtable/rhlist. The err '-EEXIST' introduced in Commit cd2b70875058 ("sctp: check duplicate node before inserting a new transport") doesn't belong to that case. So just return -EEXIST back without pr_err any kmsg. Fixes: cd2b70875058 ("sctp: check duplicate node before inserting a new transport") Reported-by: Wei Chen <weichen@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-08sctp: fix the handling of ICMP Frag Needed for too small MTUsMarcelo Ricardo Leitner
syzbot reported a hang involving SCTP, on which it kept flooding dmesg with the message: [ 246.742374] sctp: sctp_transport_update_pmtu: Reported pmtu 508 too low, using default minimum of 512 That happened because whenever SCTP hits an ICMP Frag Needed, it tries to adjust to the new MTU and triggers an immediate retransmission. But it didn't consider the fact that MTUs smaller than the SCTP minimum MTU allowed (512) would not cause the PMTU to change, and issued the retransmission anyway (thus leading to another ICMP Frag Needed, and so on). As IPv4 (ip_rt_min_pmtu=556) and IPv6 (IPV6_MIN_MTU=1280) minimum MTU are higher than that, sctp_transport_update_pmtu() is changed to re-fetch the PMTU that got set after our request, and with that, detect if there was an actual change or not. The fix, thus, skips the immediate retransmission if the received ICMP resulted in no change, in the hope that SCTP will select another path. Note: The value being used for the minimum MTU (512, SCTP_DEFAULT_MINSEGMENT) is not right and instead it should be (576, SCTP_MIN_PMTU), but such change belongs to another patch. Changes from v1: - do not disable PMTU discovery, in the light of commit 06ad391919b2 ("[SCTP] Don't disable PMTU discovery when mtu is small") and as suggested by Xin Long. - changed the way to break the rtx loop by detecting if the icmp resulted in a change or not Changes from v2: none See-also: https://lkml.org/lkml/2017/12/22/811 Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-08sctp: do not retransmit upon FragNeeded if PMTU discovery is disabledMarcelo Ricardo Leitner
Currently, if PMTU discovery is disabled on a given transport, but the configured value is higher than the actual PMTU, it is likely that we will get some icmp Frag Needed. The issue is, if PMTU discovery is disabled, we won't update the information and will issue a retransmission immediately, which may very well trigger another ICMP, and another retransmission, leading to a loop. The fix is to simply not trigger immediate retransmissions if PMTU discovery is disabled on the given transport. Changes from v2: - updated stale comment, noticed by Xin Long Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-29sctp: fix some type cast warnings introduced by transport rhashtableXin Long
These warnings were found by running 'make C=2 M=net/sctp/'. They are introduced by not aware of Endian for the port when coding transport rhashtable patches. Fixes: 7fda702f9315 ("sctp: use new rhlist interface on sctp transport rhashtable") Reported-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-20sctp: add the missing sock_owned_by_user check in sctp_icmp_redirectXin Long
Now sctp processes icmp redirect packet in sctp_icmp_redirect where it calls sctp_transport_dst_check in which tp->dst can be released. The problem is before calling sctp_transport_dst_check, it doesn't check sock_owned_by_user, which means tp->dst could be freed while a process is accessing it with owning the socket. An use-after-free issue could be triggered by this. This patch is to fix it by checking sock_owned_by_user before calling sctp_transport_dst_check in sctp_icmp_redirect, so that it would not release tp->dst if users still hold sock lock. Besides, the same issue fixed in commit 45caeaa5ac0b ("dccp/tcp: fix routing redirect race") on sctp also needs this check. Fixes: 55be7a9c6074 ("ipv4: Add redirect support to all protocol icmp error handlers") Reported-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03sctp: remove the typedef sctp_addip_chunk_tXin Long
This patch is to remove the typedef sctp_addip_chunk_t, and replace with struct sctp_addip_chunk in the places where it's using this typedef. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01sctp: remove the typedef sctp_init_chunk_tXin Long
This patch is to remove the typedef sctp_init_chunk_t, and replace with struct sctp_init_chunk in the places where it's using this typedef. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01sctp: remove the typedef sctp_chunkhdr_tXin Long
This patch is to remove the typedef sctp_chunkhdr_t, and replace with struct sctp_chunkhdr in the places where it's using this typedef. It is also to fix some indents and use sizeof(variable) instead of sizeof(type)., especially in sctp_new. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-26sctp: fix ICMP processing if skb is non-linearDavide Caratti
sometimes ICMP replies to INIT chunks are ignored by the client, even if the encapsulated SCTP headers match an open socket. This happens when the ICMP packet is carried by a paged skb: use skb_header_pointer() to read packet contents beyond the SCTP header, so that chunk header and initiate tag are validated correctly. v2: - don't use skb_header_pointer() to read the transport header, since icmp_socket_deliver() already puts these 8 bytes in the linear area. - change commit message to make specific reference to INIT chunks. Signed-off-by: Davide Caratti <dcaratti@redhat.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-05sctp: get sock from transport in sctp_transport_update_pmtuXin Long
This patch is almost to revert commit 02f3d4ce9e81 ("sctp: Adjust PMTU updates to accomodate route invalidation."). As t->asoc can't be NULL in sctp_transport_update_pmtu, it could get sk from asoc, and no need to pass sk into that function. It is also to remove some duplicated codes from that function. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-01sctp: call rcu_read_lock before checking for duplicate transport nodesXin Long
Commit cd2b70875058 ("sctp: check duplicate node before inserting a new transport") called rhltable_lookup() to check for the duplicate transport node in transport rhashtable. But rhltable_lookup() doesn't call rcu_read_lock inside, it could cause a use-after-free issue if it tries to dereference the node that another cpu has freed it. Note that sock lock can not avoid this as it is per sock. This patch is to fix it by calling rcu_read_lock before checking for duplicate transport nodes. Fixes: cd2b70875058 ("sctp: check duplicate node before inserting a new transport") Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-19sctp: check duplicate node before inserting a new transportXin Long
sctp has changed to use rhlist for transport rhashtable since commit 7fda702f9315 ("sctp: use new rhlist interface on sctp transport rhashtable"). But rhltable_insert_key doesn't check the duplicate node when inserting a node, unlike rhashtable_lookup_insert_key. It may cause duplicate assoc/transport in rhashtable. like: client (addr A, B) server (addr X, Y) connect to X INIT (1) ------------> connect to Y INIT (2) ------------> INIT_ACK (1) <------------ INIT_ACK (2) <------------ After sending INIT (2), one transport will be created and hashed into rhashtable. But when receiving INIT_ACK (1) and processing the address params, another transport will be created and hashed into rhashtable with the same addr Y and EP as the last transport. This will confuse the assoc/transport's lookup. This patch is to fix it by returning err if any duplicate node exists before inserting it. Fixes: 7fda702f9315 ("sctp: use new rhlist interface on sctp transport rhashtable") Reported-by: Fabio M. Di Nitto <fdinitto@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-28sctp: add pr_debug for tracking asocs not foundMarcelo Ricardo Leitner
This pr_debug may help identify why the system is generating some Aborts. It's not something a sysadmin would be expected to use. Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-16sctp: use new rhlist interface on sctp transport rhashtableXin Long
Now sctp transport rhashtable uses hash(lport, dport, daddr) as the key to hash a node to one chain. If in one host thousands of assocs connect to one server with the same lport and different laddrs (although it's not a normal case), all the transports would be hashed into the same chain. It may cause to keep returning -EBUSY when inserting a new node, as the chain is too long and sctp inserts a transport node in a loop, which could even lead to system hangs there. The new rhlist interface works for this case that there are many nodes with the same key in one chain. It puts them into a list then makes this list be as a node of the chain. This patch is to replace rhashtable_ interface with rhltable_ interface. Since a chain would not be too long and it would not return -EBUSY with this fix when inserting a node, the reinsert loop is also removed here. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-31sctp: hold transport instead of assoc when lookup assoc in rx pathXin Long
Prior to this patch, in rx path, before calling lock_sock, it needed to hold assoc when got it by __sctp_lookup_association, in case other place would free/put assoc. But in __sctp_lookup_association, it lookup and hold transport, then got assoc by transport->assoc, then hold assoc and put transport. It means it didn't hold transport, yet it was returned and later on directly assigned to chunk->transport. Without the protection of sock lock, the transport may be freed/put by other places, which would cause a use-after-free issue. This patch is to fix this issue by holding transport instead of assoc. As holding transport can make sure to access assoc is also safe, and actually it looks up assoc by searching transport rhashtable, to hold transport here makes more sense. Note that the function will be renamed later on on another patch. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-31sctp: return back transport in __sctp_rcv_init_lookupXin Long
Prior to this patch, it used a local variable to save the transport that is looked up by __sctp_lookup_association(), and didn't return it back. But in sctp_rcv, it is used to initialize chunk->transport. So when hitting this, even if it found the transport, it was still initializing chunk->transport with null instead. This patch is to return the transport back through transport pointer that is from __sctp_rcv_lookup_harder(). Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2016-09-22sctp: rename WORD_TRUNC/ROUND macrosMarcelo Ricardo Leitner
To something more meaningful these days, specially because this is working on packet headers or lengths and which are not tied to any CPU arch but to the protocol itself. So, WORD_TRUNC becomes SCTP_TRUNC4 and WORD_ROUND becomes SCTP_PAD4. Reported-by: David Laight <David.Laight@ACULAB.COM> Reported-by: David Miller <davem@davemloft.net> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-13sctp: hold the transport before using it in sctp_hash_cmpXin Long
Since commit 4f0087812648 ("sctp: apply rhashtable api to send/recv path"), sctp uses transport rhashtable with .obj_cmpfn sctp_hash_cmp, in which it compares the members of the transport with the rhashtable args to check if it's the right transport. But sctp uses the transport without holding it in sctp_hash_cmp, it can cause a use-after-free panic. As after it gets transport from hashtable, another CPU may close the sk and free the asoc. In sctp_association_free, it frees all the transports, meanwhile, the assoc's refcnt may be reduced to 0, assoc can be destroyed by sctp_association_destroy. So after that, transport->assoc is actually an unavailable memory address in sctp_hash_cmp. Although sctp_hash_cmp is under rcu_read_lock, it still can not avoid this, as assoc is not freed by RCU. This patch is to hold the transport before checking it's members with sctp_transport_hold, in which it checks the refcnt first, holds it if it's not 0. Fixes: 4f0087812648 ("sctp: apply rhashtable api to send/recv path") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-19sctp: linearize early if it's not GSOMarcelo Ricardo Leitner
Because otherwise when crc computation is still needed it's way more expensive than on a linear buffer to the point that it affects performance. It's so expensive that netperf test gives a perf output as below: Overhead Command Shared Object Symbol 18,62% netserver [kernel.vmlinux] [k] crc32_generic_shift 2,57% netserver [kernel.vmlinux] [k] __pskb_pull_tail 1,94% netserver [kernel.vmlinux] [k] fib_table_lookup 1,90% netserver [kernel.vmlinux] [k] copy_user_enhanced_fast_string 1,66% swapper [kernel.vmlinux] [k] intel_idle 1,63% netserver [kernel.vmlinux] [k] _raw_spin_lock 1,59% netserver [sctp] [k] sctp_packet_transmit 1,55% netserver [kernel.vmlinux] [k] memcpy_erms 1,42% netserver [sctp] [k] sctp_rcv # netperf -H 192.168.10.1 -l 10 -t SCTP_STREAM -cC -- -m 12000 SCTP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.10.1 () port 0 AF_INET Recv Send Send Utilization Service Demand Socket Socket Message Elapsed Send Recv Send Recv Size Size Size Time Throughput local remote local remote bytes bytes bytes secs. 10^6bits/s % S % S us/KB us/KB 212992 212992 12000 10.00 3016.42 2.88 3.78 1.874 2.462 After patch: Overhead Command Shared Object Symbol 2,75% netserver [kernel.vmlinux] [k] memcpy_erms 2,63% netserver [kernel.vmlinux] [k] copy_user_enhanced_fast_string 2,39% netserver [kernel.vmlinux] [k] fib_table_lookup 2,04% netserver [kernel.vmlinux] [k] __pskb_pull_tail 1,91% netserver [kernel.vmlinux] [k] _raw_spin_lock 1,91% netserver [sctp] [k] sctp_packet_transmit 1,72% netserver [mlx4_en] [k] mlx4_en_process_rx_cq 1,68% netserver [sctp] [k] sctp_rcv # netperf -H 192.168.10.1 -l 10 -t SCTP_STREAM -cC -- -m 12000 SCTP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.10.1 () port 0 AF_INET Recv Send Send Utilization Service Demand Socket Socket Message Elapsed Send Recv Send Recv Size Size Size Time Throughput local remote local remote bytes bytes bytes secs. 10^6bits/s % S % S us/KB us/KB 212992 212992 12000 10.00 3681.77 3.83 3.46 2.045 1.849 Fixes: 3acb50c18d8d ("sctp: delay as much as possible skb_linearize") Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-25sctp: fix BH handling on socket backlogMarcelo Ricardo Leitner
Now that the backlog processing is called with BH enabled, we have to disable BH before taking the socket lock via bh_lock_sock() otherwise it may dead lock: sctp_backlog_rcv() bh_lock_sock(sk); if (sock_owned_by_user(sk)) { if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) sctp_chunk_free(chunk); else backloged = 1; } else sctp_inq_push(inqueue, chunk); bh_unlock_sock(sk); while sctp_inq_push() was disabling/enabling BH, but enabling BH triggers pending softirq, which then may try to re-lock the socket in sctp_rcv(). [ 219.187215] <IRQ> [ 219.187217] [<ffffffff817ca3e0>] _raw_spin_lock+0x20/0x30 [ 219.187223] [<ffffffffa041888c>] sctp_rcv+0x48c/0xba0 [sctp] [ 219.187225] [<ffffffff816e7db2>] ? nf_iterate+0x62/0x80 [ 219.187226] [<ffffffff816f1b14>] ip_local_deliver_finish+0x94/0x1e0 [ 219.187228] [<ffffffff816f1e1f>] ip_local_deliver+0x6f/0xf0 [ 219.187229] [<ffffffff816f1a80>] ? ip_rcv_finish+0x3b0/0x3b0 [ 219.187230] [<ffffffff816f17a8>] ip_rcv_finish+0xd8/0x3b0 [ 219.187232] [<ffffffff816f2122>] ip_rcv+0x282/0x3a0 [ 219.187233] [<ffffffff810d8bb6>] ? update_curr+0x66/0x180 [ 219.187235] [<ffffffff816abac4>] __netif_receive_skb_core+0x524/0xa90 [ 219.187236] [<ffffffff810d8e00>] ? update_cfs_shares+0x30/0xf0 [ 219.187237] [<ffffffff810d557c>] ? __enqueue_entity+0x6c/0x70 [ 219.187239] [<ffffffff810dc454>] ? enqueue_entity+0x204/0xdf0 [ 219.187240] [<ffffffff816ac048>] __netif_receive_skb+0x18/0x60 [ 219.187242] [<ffffffff816ad1ce>] process_backlog+0x9e/0x140 [ 219.187243] [<ffffffff816ac8ec>] net_rx_action+0x22c/0x370 [ 219.187245] [<ffffffff817cd352>] __do_softirq+0x112/0x2e7 [ 219.187247] [<ffffffff817cc3bc>] do_softirq_own_stack+0x1c/0x30 [ 219.187247] <EOI> [ 219.187248] [<ffffffff810aa1c8>] do_softirq.part.14+0x38/0x40 [ 219.187249] [<ffffffff810aa24d>] __local_bh_enable_ip+0x7d/0x80 [ 219.187254] [<ffffffffa0408428>] sctp_inq_push+0x68/0x80 [sctp] [ 219.187258] [<ffffffffa04190f1>] sctp_backlog_rcv+0x151/0x1c0 [sctp] [ 219.187260] [<ffffffff81692b07>] __release_sock+0x87/0xf0 [ 219.187261] [<ffffffff81692ba0>] release_sock+0x30/0xa0 [ 219.187265] [<ffffffffa040e46d>] sctp_accept+0x17d/0x210 [sctp] [ 219.187266] [<ffffffff810e7510>] ? prepare_to_wait_event+0xf0/0xf0 [ 219.187268] [<ffffffff8172d52c>] inet_accept+0x3c/0x130 [ 219.187269] [<ffffffff8168d7a3>] SYSC_accept4+0x103/0x210 [ 219.187271] [<ffffffff817ca2ba>] ? _raw_spin_unlock_bh+0x1a/0x20 [ 219.187272] [<ffffffff81692bfc>] ? release_sock+0x8c/0xa0 [ 219.187276] [<ffffffffa0413e22>] ? sctp_inet_listen+0x62/0x1b0 [sctp] [ 219.187277] [<ffffffff8168f2d0>] SyS_accept+0x10/0x20 Fixes: 860fbbc343bf ("sctp: prepare for socket backlog behavior change") Cc: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-13sctp: avoid identifying address family many times for a chunkMarcelo Ricardo Leitner
Identifying address family operations during rx path is not something expensive but it's ugly to the eye to have it done multiple times, specially when we already validated it during initial rx processing. This patch takes advantage of the now shared sctp_input_cb and make the pointer to the operations readily available. Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-13sctp: allow others to use sctp_input_cbMarcelo Ricardo Leitner
We process input path in other files too and having access to it is nice, so move it to a header where it's shared. Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-03sctp: Add GSO supportMarcelo Ricardo Leitner
SCTP has this pecualiarity that its packets cannot be just segmented to (P)MTU. Its chunks must be contained in IP segments, padding respected. So we can't just generate a big skb, set gso_size to the fragmentation point and deliver it to IP layer. This patch takes a different approach. SCTP will now build a skb as it would be if it was received using GRO. That is, there will be a cover skb with protocol headers and children ones containing the actual segments, already segmented to a way that respects SCTP RFCs. With that, we can tell skb_segment() to just split based on frag_list, trusting its sizes are already in accordance. This way SCTP can benefit from GSO and instead of passing several packets through the stack, it can pass a single large packet. v2: - Added support for receiving GSO frames, as requested by Dave Miller. - Clear skb->cb if packet is GSO (otherwise it's not used by SCTP) - Added heuristics similar to what we have in TCP for not generating single GSO packets that fills cwnd. v3: - consider sctphdr size in skb_gso_transport_seglen() - rebased due to 5c7cdf339af5 ("gso: Remove arbitrary checks for unsupported GSO") Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Tested-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-03sctp: delay as much as possible skb_linearizeMarcelo Ricardo Leitner
This patch is a preparation for the GSO one. In order to successfully handle GSO packets on rx path we must not call skb_linearize, otherwise it defeats any gain GSO may have had. This patch thus delays as much as possible the call to skb_linearize, leaving it to sctp_inq_pop() moment. For that the sanity checks performed now know how to deal with fragments. One positive side-effect of this is that if the socket is backlogged it will have the chance of doing it on backlog processing instead of during softirq. With this move, it's evident that a check for non-linearity in sctp_inq_pop was ineffective and is now removed. Note that a similar check is performed a bit below this one. Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Tested-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-27net: rename NET_{ADD|INC}_STATS_BH()Eric Dumazet
Rename NET_INC_STATS_BH() to __NET_INC_STATS() and NET_ADD_STATS_BH() to __NET_ADD_STATS() Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-27net: sctp: rename SCTP_INC_STATS_BH()Eric Dumazet
Rename SCTP_INC_STATS_BH() to __SCTP_INC_STATS() Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-27net: rename ICMP_INC_STATS_BH()Eric Dumazet
Rename ICMP_INC_STATS_BH() to __ICMP_INC_STATS() Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-20sctp: align MTU to a wordMarcelo Ricardo Leitner
SCTP is a protocol that is aligned to a word (4 bytes). Thus using bare MTU can sometimes return values that are not aligned, like for loopback, which is 65536 but ipv4_mtu() limits that to 65535. This mis-alignment will cause the last non-aligned bytes to never be used and can cause issues with congestion control. So it's better to just consider a lower MTU and keep congestion control calcs saner as they are based on PMTU. Same applies to icmp frag needed messages, which is also fixed by this patch. One other effect of this is the inability to send MTU-sized packet without queueing or fragmentation and without hitting Nagle. As the check performed at sctp_packet_can_append_data(): if (chunk->skb->len + q->out_qlen >= transport->pathmtu - packet->overhead) /* Enough data queued to fill a packet */ return SCTP_XMIT_OK; with the above example of MTU, if there are no other messages queued, one cannot send a packet that just fits one packet (65532 bytes) and without causing DATA chunk fragmentation or a delay. v2: - Added WORD_TRUNC macro Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-13sctp: allow sctp_transmit_packet and others to use gfpMarcelo Ricardo Leitner
Currently sctp_sendmsg() triggers some calls that will allocate memory with GFP_ATOMIC even when not necessary. In the case of sctp_packet_transmit it will allocate a linear skb that will be used to construct the packet and this may cause sends to fail due to ENOMEM more often than anticipated specially with big MTUs. This patch thus allows it to inherit gfp flags from upper calls so that it can use GFP_KERNEL if it was triggered by a sctp_sendmsg call or similar. All others, like retransmits or flushes started from BH, are still allocated using GFP_ATOMIC. In netperf tests this didn't result in any performance drawbacks when memory is not too fragmented and made it trigger ENOMEM way less often. Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-17sctp: move rcu_read_lock from __sctp_lookup_association to ↵Xin Long
sctp_lookup_association __sctp_lookup_association() is only invoked by sctp_v4_err() and sctp_rcv(), both which run on the rx BH, and it has been protected by rcu_read_lock [see ip_local_deliver_finish() / ipv6_rcv()]. So we can move it to sctp_lookup_association, only let sctp_lookup_association use rcu_read_lock. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-28sctp: fix the transport dead race check by using atomic_add_unless on refcntXin Long
Now when __sctp_lookup_association is running in BH, it will try to check if t->dead is set, but meanwhile other CPUs may be freeing this transport and this assoc and if it happens that __sctp_lookup_association checked t->dead a bit too early, it may think that the association is still good while it was already freed. So we fix this race by using atomic_add_unless in sctp_transport_hold. After we get one transport from hashtable, we will hold it only when this transport's refcnt is not 0, so that we can make sure t->asoc cannot be freed before we hold the asoc again. Note that sctp association is not freed using RCU so we can't use atomic_add_unless() with it as it may just be too late for that either. Fixes: 4f0087812648 ("sctp: apply rhashtable api to send/recv path") Reported-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-17sctp: the temp asoc's transports should not be hashed/unhashedXin Long
Re-establish the previous behavior and avoid hashing temporary asocs by checking t->asoc->temp in sctp_(un)hash_transport. Also, remove the check of t->asoc->temp in __sctp_lookup_association, since they are never hashed now. Fixes: 4f0087812648 ("sctp: apply rhashtable api to send/recv path") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Reported-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-15sctp: support to lookup with ep+paddr in transport rhashtableXin Long
Now, when we sendmsg, we translate the ep to laddr by selecting the first element of the list, and then do a lookup for a transport. But sctp_hash_cmp() will compare it against asoc addr_list, which may be a subset of ep addr_list, meaning that this chosen laddr may not be there, and thus making it impossible to find the transport. So we fix it by using ep + paddr to lookup transports in hashtable. In sctp_hash_cmp, if .ep is set, we will check if this ep == asoc->ep, or we will do the laddr check. Fixes: d6c0256a60e6 ("sctp: add the rhashtable apis for sctp global transport hashtable") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Reported-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-05sctp: drop the old assoc hashtable of sctpXin Long
transport hashtable will replace the association hashtable, so association hashtable is not used in sctp any more, so drop the codes about that. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-05sctp: apply rhashtable api to send/recv pathXin Long
apply lookup apis to two functions, for __sctp_endpoint_lookup_assoc and __sctp_lookup_association, it's invoked in the protection of sock lock, it will be safe, but sctp_lookup_association need to call rcu_read_lock() and to detect the t->dead to protect it. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-05sctp: add the rhashtable apis for sctp global transport hashtableXin Long
tranport hashtbale will replace the association hashtable to do the lookup for transport, and then get association by t->assoc, rhashtable apis will be used because of it's resizable, scalable and using rcu. lport + rport + paddr will be the base hashkey to locate the chain, with net to protect one netns from another, then plus the laddr to compare to get the target. this patch will provider the lookup functions: - sctp_epaddr_lookup_transport - sctp_addrs_lookup_transport hash/unhash functions: - sctp_hash_transport - sctp_unhash_transport init/destroy functions: - sctp_transport_hashtable_init - sctp_transport_hashtable_destroy Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-29sctp: Change sctp to implement csum_levelsTom Herbert
CHECKSUM_UNNECESSARY may be applied to the SCTP CRC so we need to appropriate account for this by decrementing csum_level. This is done by calling __skb_dec_checksum_unnecessary. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>