kernel/linux.git/include/net/sctp, branch v4.14.152

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

sctp: potential read out of bounds in sctp_ulpevent_type_enabled()

2017-09-13T23:59:47+00:00

This code causes a static checker warning because Smatch doesn't trust anything that comes from skb->data. I've reviewed this code and I do think skb->data can be controlled by the user here. The sctp_event_subscribe struct has 13 __u8 fields and we want to see if ours is non-zero. sn_type can be any value in the 0-USHRT_MAX range. We're subtracting SCTP_SN_TYPE_BASE which is 1 << 15 so we could read either before the start of the struct or after the end. This is a very old bug and it's surprising that it would go undetected for so long but my theory is that it just doesn't have a big impact so it would be hard to notice. Signed-off-by: Dan Carpenter Signed-off-by: David S. Miller

sctp: fix some indents in sm_make_chunk.c

2017-08-11T17:02:44+00:00

There are some bad indents of functions' defination in sm_make_chunk.c. They have been there since beginning, it was probably caused by that the typedef sctp_chunk_t was replaced with struct sctp_chunk. So it's the best time to fix them in this patchset, it's also to fix some bad indents in other functions' defination in sm_make_chunk.c. Signed-off-by: Xin Long Signed-off-by: David S. Miller