kernel.git/net/sctp, branch linux-4.8.y

sctp: change sk state only when it has assocs in sctp_shutdown

2016-11-21T09:11:36Z

[ Upstream commit 5bf35ddfee052d44f39ebaa395d87101c8918405 ] Now when users shutdown a sock with SEND_SHUTDOWN in sctp, even if this sock has no connection (assoc), sk state would be changed to SCTP_SS_CLOSING, which is not as we expect. Besides, after that if users try to listen on this sock, kernel could even panic when it dereference sctp_sk(sk)->bind_hash in sctp_inet_listen, as bind_hash is null when sock has no assoc. This patch is to move sk state change after checking sk assocs is not empty, and also merge these two if() conditions and reduce indent level. Fixes: d46e416c11c8 ("sctp: sctp should change socket state when shutdown is received") Reported-by: Andrey Konovalov Tested-by: Andrey Konovalov 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: assign assoc_id earlier in __sctp_connect

2016-11-21T09:11:35Z

[ Upstream commit 7233bc84a3aeda835d334499dc00448373caf5c0 ] sctp_wait_for_connect() currently already holds the asoc to keep it alive during the sleep, in case another thread release it. But Andrey Konovalov and Dmitry Vyukov reported an use-after-free in such situation. Problem is that __sctp_connect() doesn't get a ref on the asoc and will do a read on the asoc after calling sctp_wait_for_connect(), but by then another thread may have closed it and the _put on sctp_wait_for_connect will actually release it, causing the use-after-free. Fix is, instead of doing the read after waiting for the connect, do it before so, and avoid this issue as the socket is still locked by then. There should be no issue on returning the asoc id in case of failure as the application shouldn't trust on that number in such situations anyway. This issue doesn't exist in sctp_sendmsg() path. Reported-by: Dmitry Vyukov Reported-by: Andrey Konovalov Tested-by: Andrey Konovalov Signed-off-by: Marcelo Ricardo Leitner Reviewed-by: Xin Long Acked-by: Neil Horman Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sctp: validate chunk len before actually using it

2016-11-15T06:48:53Z

[ Upstream commit bf911e985d6bbaa328c20c3e05f4eb03de11fdd6 ] Andrey Konovalov reported that KASAN detected that SCTP was using a slab beyond the boundaries. It was caused because when handling out of the blue packets in function sctp_sf_ootb() it was checking the chunk len only after already processing the first chunk, validating only for the 2nd and subsequent ones. The fix is to just move the check upwards so it's also validated for the 1st chunk. Reported-by: Andrey Konovalov Tested-by: Andrey Konovalov Signed-off-by: Marcelo Ricardo Leitner Reviewed-by: Xin Long Acked-by: Neil Horman Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sctp: fix the panic caused by route update

2016-11-15T06:48:53Z

[ Upstream commit ecc515d7238f2cffac839069d56dc271141defa0 ] Commit 7303a1475008 ("sctp: identify chunks that need to be fragmented at IP level") made the chunk be fragmented at IP level in the next round if it's size exceed PMTU. But there still is another case, PMTU can be updated if transport's dst expires and transport's pmtu_pending is set in sctp_packet_transmit. If the new PMTU is less than the chunk, the same issue with that commit can be triggered. So we should drop this packet and let it retransmit in another round where it would be fragmented at IP level. This patch is to fix it by checking the chunk size after PMTU may be updated and dropping this packet if it's size exceed PMTU. Fixes: 90017accff61 ("sctp: Add GSO support") Signed-off-by: Xin Long Acked-by: Neil Horman Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: sctp, forbid negative length

2016-11-15T06:48:53Z

[ Upstream commit a4b8e71b05c27bae6bad3bdecddbc6b68a3ad8cf ] Most of getsockopt handlers in net/sctp/socket.c check len against sizeof some structure like: if (len < sizeof(int)) return -EINVAL; On the first look, the check seems to be correct. But since len is int and sizeof returns size_t, int gets promoted to unsigned size_t too. So the test returns false for negative lengths. Yes, (-1 < sizeof(long)) is false. Fix this in sctp by explicitly checking len < 0 before any getsockopt handler is called. Note that sctp_getsockopt_events already handled the negative case. Since we added the < 0 check elsewhere, this one can be removed. If not checked, this is the result: UBSAN: Undefined behaviour in ../mm/page_alloc.c:2722:19 shift exponent 52 is too large for 32-bit type 'int' CPU: 1 PID: 24535 Comm: syz-executor Not tainted 4.8.1-0-syzkaller #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014 0000000000000000 ffff88006d99f2a8 ffffffffb2f7bdea 0000000041b58ab3 ffffffffb4363c14 ffffffffb2f7bcde ffff88006d99f2d0 ffff88006d99f270 0000000000000000 0000000000000000 0000000000000034 ffffffffb5096422 Call Trace: [] ? __ubsan_handle_shift_out_of_bounds+0x29c/0x300 ... [] ? kmalloc_order+0x24/0x90 [] ? kmalloc_order_trace+0x24/0x220 [] ? __kmalloc+0x330/0x540 [] ? sctp_getsockopt_local_addrs+0x174/0xca0 [sctp] [] ? sctp_getsockopt+0x10d/0x1b0 [sctp] [] ? sock_common_getsockopt+0xb9/0x150 [] ? SyS_getsockopt+0x1a5/0x270 Signed-off-by: Jiri Slaby Cc: Vlad Yasevich Cc: Neil Horman Cc: "David S. Miller" Cc: linux-sctp@vger.kernel.org Cc: netdev@vger.kernel.org Acked-by: Neil Horman Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sctp: fix the issue sctp_diag uses lock_sock in rcu_read_lock

2016-09-30T06:08:57Z

When sctp dumps all the ep->assocs, it needs to lock_sock first, but now it locks sock in rcu_read_lock, and lock_sock may sleep, which would break rcu_read_lock. This patch is to get and hold one sock when traversing the list. After that and get out of rcu_read_lock, lock and dump it. Then it will traverse the list again to get the next one until all sctp socks are dumped. For sctp_diag_dump_one, it fixes this issue by holding asoc and moving cb() out of rcu_read_lock in sctp_transport_lookup_process. Fixes: 8f840e47f190 ("sctp: add the sctp_diag.c file") Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: change to check peer prsctp_capable when using prsctp polices

2016-09-30T06:07:05Z

Now before using prsctp polices, sctp uses asoc->prsctp_enable to check if prsctp is enabled. However asoc->prsctp_enable is set only means local host support prsctp, sctp should not abandon packet if peer host doesn't enable prsctp. So this patch is to use asoc->peer.prsctp_capable to check if prsctp is enabled on both side, instead of asoc->prsctp_enable, as asoc's peer.prsctp_capable is set only when local and peer both enable prsctp. Fixes: a6c2f792873a ("sctp: implement prsctp TTL policy") Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: remove prsctp_param from sctp_chunk

2016-09-30T06:07:05Z

Now sctp uses chunk->prsctp_param to save the prsctp param for all the prsctp polices, we didn't need to introduce prsctp_param to sctp_chunk. We can just use chunk->sinfo.sinfo_timetolive for RTX and BUF polices, and reuse msg->expires_at for TTL policy, as the prsctp polices and old expires policy are mutual exclusive. This patch is to remove prsctp_param from sctp_chunk, and reuse msg's expires_at for TTL and chunk's sinfo.sinfo_timetolive for RTX and BUF polices. Note that sctp can't use chunk's sinfo.sinfo_timetolive for TTL policy, as it needs a u64 variables to save the expires_at time. This one also fixes the "netperf-Throughput_Mbps -37.2% regression" issue. Fixes: a6c2f792873a ("sctp: implement prsctp TTL policy") Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: hold the transport before using it in sctp_hash_cmp

2016-09-13T15:44:58Z

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 Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: identify chunks that need to be fragmented at IP level

2016-09-10T02:18:33Z

Previously, without GSO, it was easy to identify it: if the chunk didn't fit and there was no data chunk in the packet yet, we could fragment at IP level. So if there was an auth chunk and we were bundling a big data chunk, it would fragment regardless of the size of the auth chunk. This also works for the context of PMTU reductions. But with GSO, we cannot distinguish such PMTU events anymore, as the packet is allowed to exceed PMTU. So we need another check: to ensure that the chunk that we are adding, actually fits the current PMTU. If it doesn't, trigger a flush and let it be fragmented at IP level in the next round. Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller