kernel/linux.git/include/net/sctp, branch v4.14.223

sctp: Don't advertise IPv4 addresses if ipv6only is set on the socket

2020-06-30T19:37:59+00:00

[ Upstream commit 471e39df96b9a4c4ba88a2da9e25a126624d7a9c ] If a socket is set ipv6only, it will still send IPv4 addresses in the INIT and INIT_ACK packets. This potentially misleads the peer into using them, which then would cause association termination. The fix is to not add IPv4 addresses to ipv6only sockets. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Corey Minyard Signed-off-by: Marcelo Ricardo Leitner Tested-by: Corey Minyard Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sctp: cache netns in sctp_ep_common

2019-12-05T14:38:18+00:00

[ Upstream commit 312434617cb16be5166316cf9d08ba760b1042a1 ] 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 Acked-by: Marcelo Ricardo Leitner Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

sctp: fix the issue that flags are ignored when using kernel_connect

2019-11-06T11:43:39+00:00

commit 644fbdeacf1d3edd366e44b8ba214de9d1dd66a9 upstream. Now sctp uses inet_dgram_connect as its proto_ops .connect, and the flags param can't be passed into its proto .connect where this flags is really needed. sctp works around it by getting flags from socket file in __sctp_connect. It works for connecting from userspace, as inherently the user sock has socket file and it passes f_flags as the flags param into the proto_ops .connect. However, the sock created by sock_create_kern doesn't have a socket file, and it passes the flags (like O_NONBLOCK) by using the flags param in kernel_connect, which calls proto_ops .connect later. So to fix it, this patch defines a new proto_ops .connect for sctp, sctp_inet_connect, which calls __sctp_connect() directly with this flags param. After this, the sctp's proto .connect can be removed. Note that sctp_inet_connect doesn't need to do some checks that are not needed for sctp, which makes thing better than with inet_dgram_connect. Suggested-by: Marcelo Ricardo Leitner Signed-off-by: Xin Long Acked-by: Neil Horman Acked-by: Marcelo Ricardo Leitner Reviewed-by: Michal Kubecek Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sctp: avoid running the sctp state machine recursively

2019-05-08T05:20:44+00:00

[ Upstream commit fbd019737d71e405f86549fd738f81e2ff3dd073 ] Ying triggered a call trace when doing an asconf testing: BUG: scheduling while atomic: swapper/12/0/0x10000100 Call Trace: [] dump_stack+0x19/0x1b [] __schedule_bug+0x64/0x72 [] __schedule+0x9ba/0xa00 [] __cond_resched+0x26/0x30 [] _cond_resched+0x3a/0x50 [] kmem_cache_alloc_node+0x38/0x200 [] __alloc_skb+0x5d/0x2d0 [] sctp_packet_transmit+0x610/0xa20 [sctp] [] sctp_outq_flush+0x2ce/0xc00 [sctp] [] sctp_outq_uncork+0x1c/0x20 [sctp] [] sctp_cmd_interpreter.isra.22+0xc8/0x1460 [sctp] [] sctp_do_sm+0xe1/0x350 [sctp] [] sctp_primitive_ASCONF+0x3d/0x50 [sctp] [] sctp_cmd_interpreter.isra.22+0x114/0x1460 [sctp] [] sctp_do_sm+0xe1/0x350 [sctp] [] sctp_assoc_bh_rcv+0xf4/0x1b0 [sctp] [] sctp_inq_push+0x51/0x70 [sctp] [] sctp_rcv+0xa8b/0xbd0 [sctp] As it shows, the first sctp_do_sm() running under atomic context (NET_RX softirq) invoked sctp_primitive_ASCONF() that uses GFP_KERNEL flag later, and this flag is supposed to be used in non-atomic context only. Besides, sctp_do_sm() was called recursively, which is not expected. Vlad tried to fix this recursive call in Commit c0786693404c ("sctp: Fix oops when sending queued ASCONF chunks") by introducing a new command SCTP_CMD_SEND_NEXT_ASCONF. But it didn't work as this command is still used in the first sctp_do_sm() call, and sctp_primitive_ASCONF() will be called in this command again. To avoid calling sctp_do_sm() recursively, we send the next queued ASCONF not by sctp_primitive_ASCONF(), but by sctp_sf_do_prm_asconf() in the 1st sctp_do_sm() directly. Reported-by: Ying Xu Signed-off-by: Xin Long Acked-by: Neil Horman Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sctp: get sctphdr by offset in sctp_compute_cksum

2019-04-03T04:25:10+00:00

[ Upstream commit 273160ffc6b993c7c91627f5a84799c66dfe4dee ] sctp_hdr(skb) only works when skb->transport_header is set properly. But in Netfilter, skb->transport_header for ipv6 is not guaranteed to be right value for sctphdr. It would cause to fail to check the checksum for sctp packets. So fix it by using offset, which is always right in all places. v1->v2: - Fix the changelog. Fixes: e6d8b64b34aa ("net: sctp: fix and consolidate SCTP checksumming code") Reported-by: Li Shuang Signed-off-by: Xin Long Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sctp: kfree_rcu asoc

2018-12-17T08:28:47+00:00

[ Upstream commit fb6df5a6234c38a9c551559506a49a677ac6f07a ] In sctp_hash_transport/sctp_epaddr_lookup_transport, it dereferences a transport's asoc under rcu_read_lock while asoc is freed not after a grace period, which leads to a use-after-free panic. This patch fixes it by calling kfree_rcu to make asoc be freed after a grace period. Note that only the asoc's memory is delayed to free in the patch, it won't cause sk to linger longer. Thanks Neil and Marcelo to make this clear. Fixes: 7fda702f9315 ("sctp: use new rhlist interface on sctp transport rhashtable") Fixes: cd2b70875058 ("sctp: check duplicate node before inserting a new transport") Reported-by: syzbot+0b05d8aa7cb185107483@syzkaller.appspotmail.com Reported-by: syzbot+aad231d51b1923158444@syzkaller.appspotmail.com Suggested-by: Neil Horman Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Acked-by: Neil Horman Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sctp: set frag_point in sctp_setsockopt_maxseg correctly

2018-02-25T10:07:47+00:00

commit ecca8f88da5c4260cc2bccfefd2a24976704c366 upstream. Now in sctp_setsockopt_maxseg user_frag or frag_point can be set with val >= 8 and val <= SCTP_MAX_CHUNK_LEN. But both checks are incorrect. val >= 8 means frag_point can even be less than SCTP_DEFAULT_MINSEGMENT. Then in sctp_datamsg_from_user(), when it's value is greater than cookie echo len and trying to bundle with cookie echo chunk, the first_len will overflow. The worse case is when it's value is equal as cookie echo len, first_len becomes 0, it will go into a dead loop for fragment later on. In Hangbin syzkaller testing env, oom was even triggered due to consecutive memory allocation in that loop. Besides, SCTP_MAX_CHUNK_LEN is the max size of the whole chunk, it should deduct the data header for frag_point or user_frag check. This patch does a proper check with SCTP_DEFAULT_MINSEGMENT subtracting the sctphdr and datahdr, SCTP_MAX_CHUNK_LEN subtracting datahdr when setting frag_point via sockopt. It also improves sctp_setsockopt_maxseg codes. Suggested-by: Marcelo Ricardo Leitner Reported-by: Hangbin Liu Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sctp: fix the handling of ICMP Frag Needed for too small MTUs

2018-01-17T08:45:21+00:00

[ Upstream commit b6c5734db07079c9410147b32407f2366d584e6c ] 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 Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sctp: fix some type cast warnings introduced by stream reconf

2017-10-29T09:03:24+00:00

These warnings were found by running 'make C=2 M=net/sctp/'. They are introduced by not aware of Endian when coding stream reconf patches. Since commit c0d8bab6ae51 ("sctp: add get and set sockopt for reconf_enable") enabled stream reconf feature for users, the Fixes tag below would use it. Fixes: c0d8bab6ae51 ("sctp: add get and set sockopt for reconf_enable") Reported-by: Eric Dumazet Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: fix an use-after-free issue in sctp_sock_dump

2017-09-15T21:47:49+00:00

Commit 86fdb3448cc1 ("sctp: ensure ep is not destroyed before doing the dump") tried to fix an use-after-free issue by checking !sctp_sk(sk)->ep with holding sock and sock lock. But Paolo noticed that endpoint could be destroyed in sctp_rcv without sock lock protection. It means the use-after-free issue still could be triggered when sctp_rcv put and destroy ep after sctp_sock_dump checks !ep, although it's pretty hard to reproduce. I could reproduce it by mdelay in sctp_rcv while msleep in sctp_close and sctp_sock_dump long time. This patch is to add another param cb_done to sctp_for_each_transport and dump ep->assocs with holding tsp after jumping out of transport's traversal in it to avoid this issue. It can also improve sctp diag dump to make it run faster, as no need to save sk into cb->args[5] and keep calling sctp_for_each_transport any more. This patch is also to use int * instead of int for the pos argument in sctp_for_each_transport, which could make postion increment only in sctp_for_each_transport and no need to keep changing cb->args[2] in sctp_sock_filter and sctp_sock_dump any more. Fixes: 86fdb3448cc1 ("sctp: ensure ep is not destroyed before doing the dump") Reported-by: Paolo Abeni Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Acked-by: Neil Horman Signed-off-by: David S. Miller