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2014-06-26sctp: Fix sk_ack_backlog wrap-around problemXufeng Zhang
[ Upstream commit d3217b15a19a4779c39b212358a5c71d725822ee ] Consider the scenario: For a TCP-style socket, while processing the COOKIE_ECHO chunk in sctp_sf_do_5_1D_ce(), after it has passed a series of sanity check, a new association would be created in sctp_unpack_cookie(), but afterwards, some processing maybe failed, and sctp_association_free() will be called to free the previously allocated association, in sctp_association_free(), sk_ack_backlog value is decremented for this socket, since the initial value for sk_ack_backlog is 0, after the decrement, it will be 65535, a wrap-around problem happens, and if we want to establish new associations afterward in the same socket, ABORT would be triggered since sctp deem the accept queue as full. Fix this issue by only decrementing sk_ack_backlog for associations in the endpoint's list. Fix-suggested-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Xufeng Zhang <xufeng.zhang@windriver.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-07net: sctp: test if association is dead in sctp_wake_up_waitersDaniel Borkmann
[ Upstream commit 1e1cdf8ac78793e0875465e98a648df64694a8d0 ] In function sctp_wake_up_waiters(), we need to involve a test if the association is declared dead. If so, we don't have any reference to a possible sibling association anymore and need to invoke sctp_write_space() instead, and normally walk the socket's associations and notify them of new wmem space. The reason for special casing is that otherwise, we could run into the following issue when a sctp_primitive_SEND() call from sctp_sendmsg() fails, and tries to flush an association's outq, i.e. in the following way: sctp_association_free() `-> list_del(&asoc->asocs) <-- poisons list pointer asoc->base.dead = true sctp_outq_free(&asoc->outqueue) `-> __sctp_outq_teardown() `-> sctp_chunk_free() `-> consume_skb() `-> sctp_wfree() `-> sctp_wake_up_waiters() <-- dereferences poisoned pointers if asoc->ep->sndbuf_policy=0 Therefore, only walk the list in an 'optimized' way if we find that the current association is still active. We could also use list_del_init() in addition when we call sctp_association_free(), but as Vlad suggests, we want to trap such bugs and thus leave it poisoned as is. Why is it safe to resolve the issue by testing for asoc->base.dead? Parallel calls to sctp_sendmsg() are protected under socket lock, that is lock_sock()/release_sock(). Only within that path under lock held, we're setting skb/chunk owner via sctp_set_owner_w(). Eventually, chunks are freed directly by an association still under that lock. So when traversing association list on destruction time from sctp_wake_up_waiters() via sctp_wfree(), a different CPU can't be running sctp_wfree() while another one calls sctp_association_free() as both happens under the same lock. Therefore, this can also not race with setting/testing against asoc->base.dead as we are guaranteed for this to happen in order, under lock. Further, Vlad says: the times we check asoc->base.dead is when we've cached an association pointer for later processing. In between cache and processing, the association may have been freed and is simply still around due to reference counts. We check asoc->base.dead under a lock, so it should always be safe to check and not race against sctp_association_free(). Stress-testing seems fine now, too. Fixes: cd253f9f357d ("net: sctp: wake up all assocs if sndbuf policy is per socket") Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Cc: Vlad Yasevich <vyasevic@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vlad Yasevich <vyasevic@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-07net: sctp: wake up all assocs if sndbuf policy is per socketDaniel Borkmann
[ Upstream commit 52c35befb69b005c3fc5afdaae3a5717ad013411 ] SCTP charges chunks for wmem accounting via skb->truesize in sctp_set_owner_w(), and sctp_wfree() respectively as the reverse operation. If a sender runs out of wmem, it needs to wait via sctp_wait_for_sndbuf(), and gets woken up by a call to __sctp_write_space() mostly via sctp_wfree(). __sctp_write_space() is being called per association. Although we assign sk->sk_write_space() to sctp_write_space(), which is then being done per socket, it is only used if send space is increased per socket option (SO_SNDBUF), as SOCK_USE_WRITE_QUEUE is set and therefore not invoked in sock_wfree(). Commit 4c3a5bdae293 ("sctp: Don't charge for data in sndbuf again when transmitting packet") fixed an issue where in case sctp_packet_transmit() manages to queue up more than sndbuf bytes, sctp_wait_for_sndbuf() will never be woken up again unless it is interrupted by a signal. However, a still remaining issue is that if net.sctp.sndbuf_policy=0, that is accounting per socket, and one-to-many sockets are in use, the reclaimed write space from sctp_wfree() is 'unfairly' handed back on the server to the association that is the lucky one to be woken up again via __sctp_write_space(), while the remaining associations are never be woken up again (unless by a signal). The effect disappears with net.sctp.sndbuf_policy=1, that is wmem accounting per association, as it guarantees a fair share of wmem among associations. Therefore, if we have reclaimed memory in case of per socket accounting, wake all related associations to a socket in a fair manner, that is, traverse the socket association list starting from the current neighbour of the association and issue a __sctp_write_space() to everyone until we end up waking ourselves. This guarantees that no association is preferred over another and even if more associations are taken into the one-to-many session, all receivers will get messages from the server and are not stalled forever on high load. This setting still leaves the advantage of per socket accounting in touch as an association can still use up global limits if unused by others. Fixes: 4eb701dfc618 ("[SCTP] Fix SCTP sendbuffer accouting.") Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Cc: Thomas Graf <tgraf@suug.ch> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Vlad Yasevich <vyasevic@redhat.com> Acked-by: Vlad Yasevich <vyasevic@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-26net: sctp: fix skb leakage in COOKIE ECHO path of chunk->auth_chunkDaniel Borkmann
[ Upstream commit c485658bae87faccd7aed540fd2ca3ab37992310 ] While working on ec0223ec48a9 ("net: sctp: fix sctp_sf_do_5_1D_ce to verify if we/peer is AUTH capable"), we noticed that there's a skb memory leakage in the error path. Running the same reproducer as in ec0223ec48a9 and by unconditionally jumping to the error label (to simulate an error condition) in sctp_sf_do_5_1D_ce() receive path lets kmemleak detector bark about the unfreed chunk->auth_chunk skb clone: Unreferenced object 0xffff8800b8f3a000 (size 256): comm "softirq", pid 0, jiffies 4294769856 (age 110.757s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 89 ab 75 5e d4 01 58 13 00 00 00 00 00 00 00 00 ..u^..X......... backtrace: [<ffffffff816660be>] kmemleak_alloc+0x4e/0xb0 [<ffffffff8119f328>] kmem_cache_alloc+0xc8/0x210 [<ffffffff81566929>] skb_clone+0x49/0xb0 [<ffffffffa0467459>] sctp_endpoint_bh_rcv+0x1d9/0x230 [sctp] [<ffffffffa046fdbc>] sctp_inq_push+0x4c/0x70 [sctp] [<ffffffffa047e8de>] sctp_rcv+0x82e/0x9a0 [sctp] [<ffffffff815abd38>] ip_local_deliver_finish+0xa8/0x210 [<ffffffff815a64af>] nf_reinject+0xbf/0x180 [<ffffffffa04b4762>] nfqnl_recv_verdict+0x1d2/0x2b0 [nfnetlink_queue] [<ffffffffa04aa40b>] nfnetlink_rcv_msg+0x14b/0x250 [nfnetlink] [<ffffffff815a3269>] netlink_rcv_skb+0xa9/0xc0 [<ffffffffa04aa7cf>] nfnetlink_rcv+0x23f/0x408 [nfnetlink] [<ffffffff815a2bd8>] netlink_unicast+0x168/0x250 [<ffffffff815a2fa1>] netlink_sendmsg+0x2e1/0x3f0 [<ffffffff8155cc6b>] sock_sendmsg+0x8b/0xc0 [<ffffffff8155d449>] ___sys_sendmsg+0x369/0x380 What happens is that commit bbd0d59809f9 clones the skb containing the AUTH chunk in sctp_endpoint_bh_rcv() when having the edge case that an endpoint requires COOKIE-ECHO chunks to be authenticated: ---------- INIT[RANDOM; CHUNKS; HMAC-ALGO] ----------> <------- INIT-ACK[RANDOM; CHUNKS; HMAC-ALGO] --------- ------------------ AUTH; COOKIE-ECHO ----------------> <-------------------- COOKIE-ACK --------------------- When we enter sctp_sf_do_5_1D_ce() and before we actually get to the point where we process (and subsequently free) a non-NULL chunk->auth_chunk, we could hit the "goto nomem_init" path from an error condition and thus leave the cloned skb around w/o freeing it. The fix is to centrally free such clones in sctp_chunk_destroy() handler that is invoked from sctp_chunk_free() after all refs have dropped; and also move both kfree_skb(chunk->auth_chunk) there, so that chunk->auth_chunk is either NULL (since sctp_chunkify() allocs new chunks through kmem_cache_zalloc()) or non-NULL with a valid skb pointer. chunk->skb and chunk->auth_chunk are the only skbs in the sctp_chunk structure that need to be handeled. While at it, we should use consume_skb() for both. It is the same as dev_kfree_skb() but more appropriately named as we are not a device but a protocol. Also, this effectively replaces the kfree_skb() from both invocations into consume_skb(). Functions are the same only that kfree_skb() assumes that the frame was being dropped after a failure (e.g. for tools like drop monitor), usage of consume_skb() seems more appropriate in function sctp_chunk_destroy() though. Fixes: bbd0d59809f9 ("[SCTP]: Implement the receive and verification of AUTH chunk") Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Cc: Vlad Yasevich <yasevich@gmail.com> Cc: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-23net: sctp: fix sctp_sf_do_5_1D_ce to verify if we/peer is AUTH capableDaniel Borkmann
[ Upstream commit ec0223ec48a90cb605244b45f7c62de856403729 ] RFC4895 introduced AUTH chunks for SCTP; during the SCTP handshake RANDOM; CHUNKS; HMAC-ALGO are negotiated (CHUNKS being optional though): ---------- INIT[RANDOM; CHUNKS; HMAC-ALGO] ----------> <------- INIT-ACK[RANDOM; CHUNKS; HMAC-ALGO] --------- -------------------- COOKIE-ECHO --------------------> <-------------------- COOKIE-ACK --------------------- A special case is when an endpoint requires COOKIE-ECHO chunks to be authenticated: ---------- INIT[RANDOM; CHUNKS; HMAC-ALGO] ----------> <------- INIT-ACK[RANDOM; CHUNKS; HMAC-ALGO] --------- ------------------ AUTH; COOKIE-ECHO ----------------> <-------------------- COOKIE-ACK --------------------- RFC4895, section 6.3. Receiving Authenticated Chunks says: The receiver MUST use the HMAC algorithm indicated in the HMAC Identifier field. If this algorithm was not specified by the receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk during association setup, the AUTH chunk and all the chunks after it MUST be discarded and an ERROR chunk SHOULD be sent with the error cause defined in Section 4.1. [...] If no endpoint pair shared key has been configured for that Shared Key Identifier, all authenticated chunks MUST be silently discarded. [...] When an endpoint requires COOKIE-ECHO chunks to be authenticated, some special procedures have to be followed because the reception of a COOKIE-ECHO chunk might result in the creation of an SCTP association. If a packet arrives containing an AUTH chunk as a first chunk, a COOKIE-ECHO chunk as the second chunk, and possibly more chunks after them, and the receiver does not have an STCB for that packet, then authentication is based on the contents of the COOKIE-ECHO chunk. In this situation, the receiver MUST authenticate the chunks in the packet by using the RANDOM parameters, CHUNKS parameters and HMAC_ALGO parameters obtained from the COOKIE-ECHO chunk, and possibly a local shared secret as inputs to the authentication procedure specified in Section 6.3. If authentication fails, then the packet is discarded. If the authentication is successful, the COOKIE-ECHO and all the chunks after the COOKIE-ECHO MUST be processed. If the receiver has an STCB, it MUST process the AUTH chunk as described above using the STCB from the existing association to authenticate the COOKIE-ECHO chunk and all the chunks after it. [...] Commit bbd0d59809f9 introduced the possibility to receive and verification of AUTH chunk, including the edge case for authenticated COOKIE-ECHO. On reception of COOKIE-ECHO, the function sctp_sf_do_5_1D_ce() handles processing, unpacks and creates a new association if it passed sanity checks and also tests for authentication chunks being present. After a new association has been processed, it invokes sctp_process_init() on the new association and walks through the parameter list it received from the INIT chunk. It checks SCTP_PARAM_RANDOM, SCTP_PARAM_HMAC_ALGO and SCTP_PARAM_CHUNKS, and copies them into asoc->peer meta data (peer_random, peer_hmacs, peer_chunks) in case sysctl -w net.sctp.auth_enable=1 is set. If in INIT's SCTP_PARAM_SUPPORTED_EXT parameter SCTP_CID_AUTH is set, peer_random != NULL and peer_hmacs != NULL the peer is to be assumed asoc->peer.auth_capable=1, in any other case asoc->peer.auth_capable=0. Now, if in sctp_sf_do_5_1D_ce() chunk->auth_chunk is available, we set up a fake auth chunk and pass that on to sctp_sf_authenticate(), which at latest in sctp_auth_calculate_hmac() reliably dereferences a NULL pointer at position 0..0008 when setting up the crypto key in crypto_hash_setkey() by using asoc->asoc_shared_key that is NULL as condition key_id == asoc->active_key_id is true if the AUTH chunk was injected correctly from remote. This happens no matter what net.sctp.auth_enable sysctl says. The fix is to check for net->sctp.auth_enable and for asoc->peer.auth_capable before doing any operations like sctp_sf_authenticate() as no key is activated in sctp_auth_asoc_init_active_key() for each case. Now as RFC4895 section 6.3 states that if the used HMAC-ALGO passed from the INIT chunk was not used in the AUTH chunk, we SHOULD send an error; however in this case it would be better to just silently discard such a maliciously prepared handshake as we didn't even receive a parameter at all. Also, as our endpoint has no shared key configured, section 6.3 says that MUST silently discard, which we are doing from now onwards. Before calling sctp_sf_pdiscard(), we need not only to free the association, but also the chunk->auth_chunk skb, as commit bbd0d59809f9 created a skb clone in that case. I have tested this locally by using netfilter's nfqueue and re-injecting packets into the local stack after maliciously modifying the INIT chunk (removing RANDOM; HMAC-ALGO param) and the SCTP packet containing the COOKIE_ECHO (injecting AUTH chunk before COOKIE_ECHO). Fixed with this patch applied. Fixes: bbd0d59809f9 ("[SCTP]: Implement the receive and verification of AUTH chunk") Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Cc: Vlad Yasevich <yasevich@gmail.com> Cc: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-11net: sctp: fix sctp_connectx abi for ia32 emulation/compat modeDaniel Borkmann
[ Upstream commit ffd5939381c609056b33b7585fb05a77b4c695f3 ] SCTP's sctp_connectx() abi breaks for 64bit kernels compiled with 32bit emulation (e.g. ia32 emulation or x86_x32). Due to internal usage of 'struct sctp_getaddrs_old' which includes a struct sockaddr pointer, sizeof(param) check will always fail in kernel as the structure in 64bit kernel space is 4bytes larger than for user binaries compiled in 32bit mode. Thus, applications making use of sctp_connectx() won't be able to run under such circumstances. Introduce a compat interface in the kernel to deal with such situations by using a 'struct compat_sctp_getaddrs_old' structure where user data is copied into it, and then sucessively transformed into a 'struct sctp_getaddrs_old' structure with the help of compat_ptr(). That fixes sctp_connectx() abi without any changes needed in user space, and lets the SCTP test suite pass when compiled in 32bit and run on 64bit kernels. Fixes: f9c67811ebc0 ("sctp: Fix regression introduced by new sctp_connectx api") Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04sctp: Perform software checksum if packet has to be fragmented.Vlad Yasevich
[ Upstream commit d2dbbba77e95dff4b4f901fee236fef6d9552072 ] IP/IPv6 fragmentation knows how to compute only TCP/UDP checksum. This causes problems if SCTP packets has to be fragmented and ipsummed has been set to PARTIAL due to checksum offload support. This condition can happen when retransmitting after MTU discover, or when INIT or other control chunks are larger then MTU. Check for the rare fragmentation condition in SCTP and use software checksum calculation in this case. CC: Fan Du <fan.du@windriver.com> Signed-off-by: Vlad Yasevich <vyasevich@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04sctp: Use software crc32 checksum when xfrm transform will happen.Fan Du
[ Upstream commit 27127a82561a2a3ed955ce207048e1b066a80a2a ] igb/ixgbe have hardware sctp checksum support, when this feature is enabled and also IPsec is armed to protect sctp traffic, ugly things happened as xfrm_output checks CHECKSUM_PARTIAL to do checksum operation(sum every thing up and pack the 16bits result in the checksum field). The result is fail establishment of sctp communication. Signed-off-by: Fan Du <fan.du@windriver.com> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Vlad Yasevich <vyasevich@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-13net: sctp: fix ipv6 ipsec encryption bug in sctp_v6_xmitDaniel Borkmann
[ Upstream commit 95ee62083cb6453e056562d91f597552021e6ae7 ] Alan Chester reported an issue with IPv6 on SCTP that IPsec traffic is not being encrypted, whereas on IPv4 it is. Setting up an AH + ESP transport does not seem to have the desired effect: SCTP + IPv4: 22:14:20.809645 IP (tos 0x2,ECT(0), ttl 64, id 0, offset 0, flags [DF], proto AH (51), length 116) 192.168.0.2 > 192.168.0.5: AH(spi=0x00000042,sumlen=16,seq=0x1): ESP(spi=0x00000044,seq=0x1), length 72 22:14:20.813270 IP (tos 0x2,ECT(0), ttl 64, id 0, offset 0, flags [DF], proto AH (51), length 340) 192.168.0.5 > 192.168.0.2: AH(spi=0x00000043,sumlen=16,seq=0x1): SCTP + IPv6: 22:31:19.215029 IP6 (class 0x02, hlim 64, next-header SCTP (132) payload length: 364) fe80::222:15ff:fe87:7fc.3333 > fe80::92e6:baff:fe0d:5a54.36767: sctp 1) [INIT ACK] [init tag: 747759530] [rwnd: 62464] [OS: 10] [MIS: 10] Moreover, Alan says: This problem was seen with both Racoon and Racoon2. Other people have seen this with OpenSwan. When IPsec is configured to encrypt all upper layer protocols the SCTP connection does not initialize. After using Wireshark to follow packets, this is because the SCTP packet leaves Box A unencrypted and Box B believes all upper layer protocols are to be encrypted so it drops this packet, causing the SCTP connection to fail to initialize. When IPsec is configured to encrypt just SCTP, the SCTP packets are observed unencrypted. In fact, using `socat sctp6-listen:3333 -` on one end and transferring "plaintext" string on the other end, results in cleartext on the wire where SCTP eventually does not report any errors, thus in the latter case that Alan reports, the non-paranoid user might think he's communicating over an encrypted transport on SCTP although he's not (tcpdump ... -X): ... 0x0030: 5d70 8e1a 0003 001a 177d eb6c 0000 0000 ]p.......}.l.... 0x0040: 0000 0000 706c 6169 6e74 6578 740a 0000 ....plaintext... Only in /proc/net/xfrm_stat we can see XfrmInTmplMismatch increasing on the receiver side. Initial follow-up analysis from Alan's bug report was done by Alexey Dobriyan. Also thanks to Vlad Yasevich for feedback on this. SCTP has its own implementation of sctp_v6_xmit() not calling inet6_csk_xmit(). This has the implication that it probably never really got updated along with changes in inet6_csk_xmit() and therefore does not seem to invoke xfrm handlers. SCTP's IPv4 xmit however, properly calls ip_queue_xmit() to do the work. Since a call to inet6_csk_xmit() would solve this problem, but result in unecessary route lookups, let us just use the cached flowi6 instead that we got through sctp_v6_get_dst(). Since all SCTP packets are being sent through sctp_packet_transmit(), we do the route lookup / flow caching in sctp_transport_route(), hold it in tp->dst and skb_dst_set() right after that. If we would alter fl6->daddr in sctp_v6_xmit() to np->opt->srcrt, we possibly could run into the same effect of not having xfrm layer pick it up, hence, use fl6_update_dst() in sctp_v6_get_dst() instead to get the correct source routed dst entry, which we assign to the skb. Also source address routing example from 625034113 ("sctp: fix sctp to work with ipv6 source address routing") still works with this patch! Nevertheless, in RFC5095 it is actually 'recommended' to not use that anyway due to traffic amplification [1]. So it seems we're not supposed to do that anyway in sctp_v6_xmit(). Moreover, if we overwrite the flow destination here, the lower IPv6 layer will be unable to put the correct destination address into IP header, as routing header is added in ipv6_push_nfrag_opts() but then probably with wrong final destination. Things aside, result of this patch is that we do not have any XfrmInTmplMismatch increase plus on the wire with this patch it now looks like: SCTP + IPv6: 08:17:47.074080 IP6 2620:52:0:102f:7a2b:cbff:fe27:1b0a > 2620:52:0:102f:213:72ff:fe32:7eba: AH(spi=0x00005fb4,seq=0x1): ESP(spi=0x00005fb5,seq=0x1), length 72 08:17:47.074264 IP6 2620:52:0:102f:213:72ff:fe32:7eba > 2620:52:0:102f:7a2b:cbff:fe27:1b0a: AH(spi=0x00003d54,seq=0x1): ESP(spi=0x00003d55,seq=0x1), length 296 This fixes Kernel Bugzilla 24412. This security issue seems to be present since 2.6.18 kernels. Lets just hope some big passive adversary in the wild didn't have its fun with that. lksctp-tools IPv6 regression test suite passes as well with this patch. [1] http://www.secdev.org/conf/IPv6_RH_security-csw07.pdf Reported-by: Alan Chester <alan.chester@tekelec.com> Reported-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Cc: Steffen Klassert <steffen.klassert@secunet.com> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-13net: sctp: fix smatch warning in sctp_send_asconf_del_ipDaniel Borkmann
[ Upstream commit 88362ad8f9a6cea787420b57cc27ccacef000dbe ] This was originally reported in [1] and posted by Neil Horman [2], he said: Fix up a missed null pointer check in the asconf code. If we don't find a local address, but we pass in an address length of more than 1, we may dereference a NULL laddr pointer. Currently this can't happen, as the only users of the function pass in the value 1 as the addrcnt parameter, but its not hot path, and it doesn't hurt to check for NULL should that ever be the case. The callpath from sctp_asconf_mgmt() looks okay. But this could be triggered from sctp_setsockopt_bindx() call with SCTP_BINDX_REM_ADDR and addrcnt > 1 while passing all possible addresses from the bind list to SCTP_BINDX_REM_ADDR so that we do *not* find a single address in the association's bind address list that is not in the packed array of addresses. If this happens when we have an established association with ASCONF-capable peers, then we could get a NULL pointer dereference as we only check for laddr == NULL && addrcnt == 1 and call later sctp_make_asconf_update_ip() with NULL laddr. BUT: this actually won't happen as sctp_bindx_rem() will catch such a case and return with an error earlier. As this is incredably unintuitive and error prone, add a check to catch at least future bugs here. As Neil says, its not hot path. Introduced by 8a07eb0a5 ("sctp: Add ASCONF operation on the single-homed host"). [1] http://www.spinics.net/lists/linux-sctp/msg02132.html [2] http://www.spinics.net/lists/linux-sctp/msg02133.html Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Cc: Michio Honda <micchie@sfc.wide.ad.jp> Acked-By: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-01Revert "sctp: fix call to SCTP_CMD_PROCESS_SACK in sctp_cmd_interpreter()"Greg Kroah-Hartman
This reverts commit c2f5b7507ac5d808f29287d77ee6148358d7fbfe which is commit f6e80abeab928b7c47cc1fbf53df13b4398a2bec. Michal writes: Mainline commit f6e80abe was introduced in v3.7-rc2 as a follow-up fix to commit edfee033 sctp: check src addr when processing SACK to update transport state (from v3.7-rc1) which changed the interpretation of third argument to sctp_cmd_process_sack() and sctp_outq_sack(). But as commit edfee033 has never been backported to stable branches, backport of commit f6e80abe actually breaks the code rather than fixing it. Reported-by: Michal Kubecek <mkubecek@suse.cz> Cc: Zijie Pan <zijie.pan@6wind.com> Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com> Cc: Vlad Yasevich <vyasevich@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-11sctp: fully initialize sctp_outq in sctp_outq_initNeil Horman
[ Upstream commit c5c7774d7eb4397891edca9ebdf750ba90977a69 ] In commit 2f94aabd9f6c925d77aecb3ff020f1cc12ed8f86 (refactor sctp_outq_teardown to insure proper re-initalization) we modified sctp_outq_teardown to use sctp_outq_init to fully re-initalize the outq structure. Steve West recently asked me why I removed the q->error = 0 initalization from sctp_outq_teardown. I did so because I was operating under the impression that sctp_outq_init would properly initalize that value for us, but it doesn't. sctp_outq_init operates under the assumption that the outq struct is all 0's (as it is when called from sctp_association_init), but using it in __sctp_outq_teardown violates that assumption. We should do a memset in sctp_outq_init to ensure that the entire structure is in a known state there instead. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Reported-by: "West, Steve (NSN - US/Fort Worth)" <steve.west@nsn.com> CC: Vlad Yasevich <vyasevich@gmail.com> CC: netdev@vger.kernel.org CC: davem@davemloft.net Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-27net: sctp: fix NULL pointer dereference in socket destructionDaniel Borkmann
[ Upstream commit 1abd165ed757db1afdefaac0a4bc8a70f97d258c ] While stress testing sctp sockets, I hit the following panic: BUG: unable to handle kernel NULL pointer dereference at 0000000000000020 IP: [<ffffffffa0490c4e>] sctp_endpoint_free+0xe/0x40 [sctp] PGD 7cead067 PUD 7ce76067 PMD 0 Oops: 0000 [#1] SMP Modules linked in: sctp(F) libcrc32c(F) [...] CPU: 7 PID: 2950 Comm: acc Tainted: GF 3.10.0-rc2+ #1 Hardware name: Dell Inc. PowerEdge T410/0H19HD, BIOS 1.6.3 02/01/2011 task: ffff88007ce0e0c0 ti: ffff88007b568000 task.ti: ffff88007b568000 RIP: 0010:[<ffffffffa0490c4e>] [<ffffffffa0490c4e>] sctp_endpoint_free+0xe/0x40 [sctp] RSP: 0018:ffff88007b569e08 EFLAGS: 00010292 RAX: 0000000000000000 RBX: ffff88007db78a00 RCX: dead000000200200 RDX: ffffffffa049fdb0 RSI: ffff8800379baf38 RDI: 0000000000000000 RBP: ffff88007b569e18 R08: ffff88007c230da0 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff880077990d00 R14: 0000000000000084 R15: ffff88007db78a00 FS: 00007fc18ab61700(0000) GS:ffff88007fc60000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000020 CR3: 000000007cf9d000 CR4: 00000000000007e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Stack: ffff88007b569e38 ffff88007db78a00 ffff88007b569e38 ffffffffa049fded ffffffff81abf0c0 ffff88007db78a00 ffff88007b569e58 ffffffff8145b60e 0000000000000000 0000000000000000 ffff88007b569eb8 ffffffff814df36e Call Trace: [<ffffffffa049fded>] sctp_destroy_sock+0x3d/0x80 [sctp] [<ffffffff8145b60e>] sk_common_release+0x1e/0xf0 [<ffffffff814df36e>] inet_create+0x2ae/0x350 [<ffffffff81455a6f>] __sock_create+0x11f/0x240 [<ffffffff81455bf0>] sock_create+0x30/0x40 [<ffffffff8145696c>] SyS_socket+0x4c/0xc0 [<ffffffff815403be>] ? do_page_fault+0xe/0x10 [<ffffffff8153cb32>] ? page_fault+0x22/0x30 [<ffffffff81544e02>] system_call_fastpath+0x16/0x1b Code: 0c c9 c3 66 2e 0f 1f 84 00 00 00 00 00 e8 fb fe ff ff c9 c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 53 48 83 ec 08 66 66 66 66 90 <48> 8b 47 20 48 89 fb c6 47 1c 01 c6 40 12 07 e8 9e 68 01 00 48 RIP [<ffffffffa0490c4e>] sctp_endpoint_free+0xe/0x40 [sctp] RSP <ffff88007b569e08> CR2: 0000000000000020 ---[ end trace e0d71ec1108c1dd9 ]--- I did not hit this with the lksctp-tools functional tests, but with a small, multi-threaded test program, that heavily allocates, binds, listens and waits in accept on sctp sockets, and then randomly kills some of them (no need for an actual client in this case to hit this). Then, again, allocating, binding, etc, and then killing child processes. This panic then only occurs when ``echo 1 > /proc/sys/net/sctp/auth_enable'' is set. The cause for that is actually very simple: in sctp_endpoint_init() we enter the path of sctp_auth_init_hmacs(). There, we try to allocate our crypto transforms through crypto_alloc_hash(). In our scenario, it then can happen that crypto_alloc_hash() fails with -EINTR from crypto_larval_wait(), thus we bail out and release the socket via sk_common_release(), sctp_destroy_sock() and hit the NULL pointer dereference as soon as we try to access members in the endpoint during sctp_endpoint_free(), since endpoint at that time is still NULL. Now, if we have that case, we do not need to do any cleanup work and just leave the destruction handler. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-01net: sctp: sctp_auth_key_put: use kzfree instead of kfreeDaniel Borkmann
[ Upstream commit 586c31f3bf04c290dc0a0de7fc91d20aa9a5ee53 ] For sensitive data like keying material, it is common practice to zero out keys before returning the memory back to the allocator. Thus, use kzfree instead of kfree. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-28sctp: don't break the loop while meeting the active_path so as to find the ↵Xufeng Zhang
matched transport [ Upstream commit 2317f449af30073cfa6ec8352e4a65a89e357bdd ] sctp_assoc_lookup_tsn() function searchs which transport a certain TSN was sent on, if not found in the active_path transport, then go search all the other transports in the peer's transport_addr_list, however, we should continue to the next entry rather than break the loop when meet the active_path transport. Signed-off-by: Xufeng Zhang <xufeng.zhang@windriver.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-28sctp: Use correct sideffect command in duplicate cookie handlingVlad Yasevich
[ Upstream commit f2815633504b442ca0b0605c16bf3d88a3a0fcea ] When SCTP is done processing a duplicate cookie chunk, it tries to delete a newly created association. For that, it has to set the right association for the side-effect processing to work. However, when it uses the SCTP_CMD_NEW_ASOC command, that performs more work then really needed (like hashing the associationa and assigning it an id) and there is no point to do that only to delete the association as a next step. In fact, it also creates an impossible condition where an association may be found by the getsockopt() call, and that association is empty. This causes a crash in some sctp getsockopts. The solution is rather simple. We simply use SCTP_CMD_SET_ASOC command that doesn't have all the overhead and does exactly what we need. Reported-by: Karl Heiss <kheiss@gmail.com> Tested-by: Karl Heiss <kheiss@gmail.com> CC: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Vlad Yasevich <vyasevich@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-14net: sctp: sctp_endpoint_free: zero out secret key dataDaniel Borkmann
[ Upstream commit b5c37fe6e24eec194bb29d22fdd55d73bcc709bf ] On sctp_endpoint_destroy, previously used sensitive keying material should be zeroed out before the memory is returned, as we already do with e.g. auth keys when released. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Vlad Yasevich <vyasevic@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-14net: sctp: sctp_setsockopt_auth_key: use kzfree instead of kfreeDaniel Borkmann
[ Upstream commit 6ba542a291a5e558603ac51cda9bded347ce7627 ] In sctp_setsockopt_auth_key, we create a temporary copy of the user passed shared auth key for the endpoint or association and after internal setup, we free it right away. Since it's sensitive data, we should zero out the key before returning the memory back to the allocator. Thus, use kzfree instead of kfree, just as we do in sctp_auth_key_put(). Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-14sctp: refactor sctp_outq_teardown to insure proper re-initalizationNeil Horman
[ Upstream commit 2f94aabd9f6c925d77aecb3ff020f1cc12ed8f86 ] Jamie Parsons reported a problem recently, in which the re-initalization of an association (The duplicate init case), resulted in a loss of receive window space. He tracked down the root cause to sctp_outq_teardown, which discarded all the data on an outq during a re-initalization of the corresponding association, but never reset the outq->outstanding_data field to zero. I wrote, and he tested this fix, which does a proper full re-initalization of the outq, fixing this problem, and hopefully future proofing us from simmilar issues down the road. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Reported-by: Jamie Parsons <Jamie.Parsons@metaswitch.com> Tested-by: Jamie Parsons <Jamie.Parsons@metaswitch.com> CC: Jamie Parsons <Jamie.Parsons@metaswitch.com> CC: Vlad Yasevich <vyasevich@gmail.com> CC: "David S. Miller" <davem@davemloft.net> CC: netdev@vger.kernel.org Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-11sctp: fix -ENOMEM result with invalid user space pointer in sendto() syscallTommi Rantala
[ Upstream commit 6e51fe7572590d8d86e93b547fab6693d305fd0d ] Consider the following program, that sets the second argument to the sendto() syscall incorrectly: #include <string.h> #include <arpa/inet.h> #include <sys/socket.h> int main(void) { int fd; struct sockaddr_in sa; fd = socket(AF_INET, SOCK_STREAM, 132 /*IPPROTO_SCTP*/); if (fd < 0) return 1; memset(&sa, 0, sizeof(sa)); sa.sin_family = AF_INET; sa.sin_addr.s_addr = inet_addr("127.0.0.1"); sa.sin_port = htons(11111); sendto(fd, NULL, 1, 0, (struct sockaddr *)&sa, sizeof(sa)); return 0; } We get -ENOMEM: $ strace -e sendto ./demo sendto(3, NULL, 1, 0, {sa_family=AF_INET, sin_port=htons(11111), sin_addr=inet_addr("127.0.0.1")}, 16) = -1 ENOMEM (Cannot allocate memory) Propagate the error code from sctp_user_addto_chunk(), so that we will tell user space what actually went wrong: $ strace -e sendto ./demo sendto(3, NULL, 1, 0, {sa_family=AF_INET, sin_port=htons(11111), sin_addr=inet_addr("127.0.0.1")}, 16) = -1 EFAULT (Bad address) Noticed while running Trinity (the syscall fuzzer). Signed-off-by: Tommi Rantala <tt.rantala@gmail.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-11sctp: fix memory leak in sctp_datamsg_from_user() when copy from user space ↵Tommi Rantala
fails [ Upstream commit be364c8c0f17a3dd42707b5a090b318028538eb9 ] Trinity (the syscall fuzzer) discovered a memory leak in SCTP, reproducible e.g. with the sendto() syscall by passing invalid user space pointer in the second argument: #include <string.h> #include <arpa/inet.h> #include <sys/socket.h> int main(void) { int fd; struct sockaddr_in sa; fd = socket(AF_INET, SOCK_STREAM, 132 /*IPPROTO_SCTP*/); if (fd < 0) return 1; memset(&sa, 0, sizeof(sa)); sa.sin_family = AF_INET; sa.sin_addr.s_addr = inet_addr("127.0.0.1"); sa.sin_port = htons(11111); sendto(fd, NULL, 1, 0, (struct sockaddr *)&sa, sizeof(sa)); return 0; } As far as I can tell, the leak has been around since ~2003. Signed-off-by: Tommi Rantala <tt.rantala@gmail.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-17sctp: fix call to SCTP_CMD_PROCESS_SACK in sctp_cmd_interpreter()Zijie Pan
[ Upstream commit f6e80abeab928b7c47cc1fbf53df13b4398a2bec ] Bug introduced by commit edfee0339e681a784ebacec7e8c2dc97dc6d2839 (sctp: check src addr when processing SACK to update transport state) Signed-off-by: Zijie Pan <zijie.pan@6wind.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-13sctp: Don't charge for data in sndbuf again when transmitting packetThomas Graf
[ Upstream commit 4c3a5bdae293f75cdf729c6c00124e8489af2276 ] SCTP charges wmem_alloc via sctp_set_owner_w() in sctp_sendmsg() and via skb_set_owner_w() in sctp_packet_transmit(). If a sender runs out of sndbuf it will sleep in sctp_wait_for_sndbuf() and expects to be waken up by __sctp_write_space(). Buffer space charged via sctp_set_owner_w() is released in sctp_wfree() which calls __sctp_write_space() directly. Buffer space charged via skb_set_owner_w() is released via sock_wfree() which calls sk->sk_write_space() _if_ SOCK_USE_WRITE_QUEUE is not set. sctp_endpoint_init() sets SOCK_USE_WRITE_QUEUE on all sockets. Therefore if sctp_packet_transmit() manages to queue up more than sndbuf bytes, sctp_wait_for_sndbuf() will never be woken up again unless it is interrupted by a signal. This could be fixed by clearing the SOCK_USE_WRITE_QUEUE flag but ... Charging for the data twice does not make sense in the first place, it leads to overcharging sndbuf by a factor 2. Therefore this patch only charges a single byte in wmem_alloc when transmitting an SCTP packet to ensure that the socket stays alive until the packet has been released. This means that control chunks are no longer accounted for in wmem_alloc which I believe is not a problem as skb->truesize will typically lead to overcharging anyway and thus compensates for any control overhead. Signed-off-by: Thomas Graf <tgraf@suug.ch> CC: Vlad Yasevich <vyasevic@redhat.com> CC: Neil Horman <nhorman@tuxdriver.com> CC: David Miller <davem@davemloft.net> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-09sctp: Fix list corruption resulting from freeing an association on a listNeil Horman
[ Upstream commit 2eebc1e188e9e45886ee00662519849339884d6d ] A few days ago Dave Jones reported this oops: [22766.294255] general protection fault: 0000 [#1] PREEMPT SMP [22766.295376] CPU 0 [22766.295384] Modules linked in: [22766.387137] ffffffffa169f292 6b6b6b6b6b6b6b6b ffff880147c03a90 ffff880147c03a74 [22766.387135] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 00000000000 [22766.387136] Process trinity-watchdo (pid: 10896, threadinfo ffff88013e7d2000, [22766.387137] Stack: [22766.387140] ffff880147c03a10 [22766.387140] ffffffffa169f2b6 [22766.387140] ffff88013ed95728 [22766.387143] 0000000000000002 [22766.387143] 0000000000000000 [22766.387143] ffff880003fad062 [22766.387144] ffff88013c120000 [22766.387144] [22766.387145] Call Trace: [22766.387145] <IRQ> [22766.387150] [<ffffffffa169f292>] ? __sctp_lookup_association+0x62/0xd0 [sctp] [22766.387154] [<ffffffffa169f2b6>] __sctp_lookup_association+0x86/0xd0 [sctp] [22766.387157] [<ffffffffa169f597>] sctp_rcv+0x207/0xbb0 [sctp] [22766.387161] [<ffffffff810d4da8>] ? trace_hardirqs_off_caller+0x28/0xd0 [22766.387163] [<ffffffff815827e3>] ? nf_hook_slow+0x133/0x210 [22766.387166] [<ffffffff815902fc>] ? ip_local_deliver_finish+0x4c/0x4c0 [22766.387168] [<ffffffff8159043d>] ip_local_deliver_finish+0x18d/0x4c0 [22766.387169] [<ffffffff815902fc>] ? ip_local_deliver_finish+0x4c/0x4c0 [22766.387171] [<ffffffff81590a07>] ip_local_deliver+0x47/0x80 [22766.387172] [<ffffffff8158fd80>] ip_rcv_finish+0x150/0x680 [22766.387174] [<ffffffff81590c54>] ip_rcv+0x214/0x320 [22766.387176] [<ffffffff81558c07>] __netif_receive_skb+0x7b7/0x910 [22766.387178] [<ffffffff8155856c>] ? __netif_receive_skb+0x11c/0x910 [22766.387180] [<ffffffff810d423e>] ? put_lock_stats.isra.25+0xe/0x40 [22766.387182] [<ffffffff81558f83>] netif_receive_skb+0x23/0x1f0 [22766.387183] [<ffffffff815596a9>] ? dev_gro_receive+0x139/0x440 [22766.387185] [<ffffffff81559280>] napi_skb_finish+0x70/0xa0 [22766.387187] [<ffffffff81559cb5>] napi_gro_receive+0xf5/0x130 [22766.387218] [<ffffffffa01c4679>] e1000_receive_skb+0x59/0x70 [e1000e] [22766.387242] [<ffffffffa01c5aab>] e1000_clean_rx_irq+0x28b/0x460 [e1000e] [22766.387266] [<ffffffffa01c9c18>] e1000e_poll+0x78/0x430 [e1000e] [22766.387268] [<ffffffff81559fea>] net_rx_action+0x1aa/0x3d0 [22766.387270] [<ffffffff810a495f>] ? account_system_vtime+0x10f/0x130 [22766.387273] [<ffffffff810734d0>] __do_softirq+0xe0/0x420 [22766.387275] [<ffffffff8169826c>] call_softirq+0x1c/0x30 [22766.387278] [<ffffffff8101db15>] do_softirq+0xd5/0x110 [22766.387279] [<ffffffff81073bc5>] irq_exit+0xd5/0xe0 [22766.387281] [<ffffffff81698b03>] do_IRQ+0x63/0xd0 [22766.387283] [<ffffffff8168ee2f>] common_interrupt+0x6f/0x6f [22766.387283] <EOI> [22766.387284] [22766.387285] [<ffffffff8168eed9>] ? retint_swapgs+0x13/0x1b [22766.387285] Code: c0 90 5d c3 66 0f 1f 44 00 00 4c 89 c8 5d c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89 5d e8 4c 89 65 f0 4c 89 6d f8 66 66 66 66 90 <0f> b7 87 98 00 00 00 48 89 fb 49 89 f5 66 c1 c0 08 66 39 46 02 [22766.387307] [22766.387307] RIP [22766.387311] [<ffffffffa168a2c9>] sctp_assoc_is_match+0x19/0x90 [sctp] [22766.387311] RSP <ffff880147c039b0> [22766.387142] ffffffffa16ab120 [22766.599537] ---[ end trace 3f6dae82e37b17f5 ]--- [22766.601221] Kernel panic - not syncing: Fatal exception in interrupt It appears from his analysis and some staring at the code that this is likely occuring because an association is getting freed while still on the sctp_assoc_hashtable. As a result, we get a gpf when traversing the hashtable while a freed node corrupts part of the list. Nominally I would think that an mibalanced refcount was responsible for this, but I can't seem to find any obvious imbalance. What I did note however was that the two places where we create an association using sctp_primitive_ASSOCIATE (__sctp_connect and sctp_sendmsg), have failure paths which free a newly created association after calling sctp_primitive_ASSOCIATE. sctp_primitive_ASSOCIATE brings us into the sctp_sf_do_prm_asoc path, which issues a SCTP_CMD_NEW_ASOC side effect, which in turn adds a new association to the aforementioned hash table. the sctp command interpreter that process side effects has not way to unwind previously processed commands, so freeing the association from the __sctp_connect or sctp_sendmsg error path would lead to a freed association remaining on this hash table. I've fixed this but modifying sctp_[un]hash_established to use hlist_del_init, which allows us to proerly use hlist_unhashed to check if the node is on a hashlist safely during a delete. That in turn alows us to safely call sctp_unhash_established in the __sctp_connect and sctp_sendmsg error paths before freeing them, regardles of what the associations state is on the hash list. I noted, while I was doing this, that the __sctp_unhash_endpoint was using hlist_unhsashed in a simmilar fashion, but never nullified any removed nodes pointers to make that function work properly, so I fixed that up in a simmilar fashion. I attempted to test this using a virtual guest running the SCTP_RR test from netperf in a loop while running the trinity fuzzer, both in a loop. I wasn't able to recreate the problem prior to this fix, nor was I able to trigger the failure after (neither of which I suppose is suprising). Given the trace above however, I think its likely that this is what we hit. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Reported-by: davej@redhat.com CC: davej@redhat.com CC: "David S. Miller" <davem@davemloft.net> CC: Vlad Yasevich <vyasevich@gmail.com> CC: Sridhar Samudrala <sri@us.ibm.com> CC: linux-sctp@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-10sctp: check cached dst before using itNicolas Dichtel
dst_check() will take care of SA (and obsolete field), hence IPsec rekeying scenario is taken into account. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Vlad Yaseivch <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-04sctp: Allow struct sctp_event_subscribe to grow without breaking binariesThomas Graf
getsockopt(..., SCTP_EVENTS, ...) performs a length check and returns an error if the user provides less bytes than the size of struct sctp_event_subscribe. Struct sctp_event_subscribe needs to be extended by an u8 for every new event or notification type that is added. This obviously makes getsockopt fail for binaries that are compiled against an older versions of <net/sctp/user.h> which do not contain all event types. This patch changes getsockopt behaviour to no longer return an error if not enough bytes are being provided by the user. Instead, it returns as much of sctp_event_subscribe as fits into the provided buffer. This leads to the new behavior that users see what they have been aware of at compile time. The setsockopt(..., SCTP_EVENTS, ...) API is already behaving like this. Signed-off-by: Thomas Graf <tgraf@suug.ch> Acked-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-08sctp: Export sctp_do_peeloffBenjamin Poirier
lookup sctp_association within sctp_do_peeloff() to enable its use outside of the sctp code with minimal knowledge of the former. Signed-off-by: Benjamin Poirier <bpoirier@suse.de> Acked-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-08Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (53 commits) Kconfig: acpi: Fix typo in comment. misc latin1 to utf8 conversions devres: Fix a typo in devm_kfree comment btrfs: free-space-cache.c: remove extra semicolon. fat: Spelling s/obsolate/obsolete/g SCSI, pmcraid: Fix spelling error in a pmcraid_err() call tools/power turbostat: update fields in manpage mac80211: drop spelling fix types.h: fix comment spelling for 'architectures' typo fixes: aera -> area, exntension -> extension devices.txt: Fix typo of 'VMware'. sis900: Fix enum typo 'sis900_rx_bufer_status' decompress_bunzip2: remove invalid vi modeline treewide: Fix comment and string typo 'bufer' hyper-v: Update MAINTAINERS treewide: Fix typos in various parts of the kernel, and fix some comments. clockevents: drop unknown Kconfig symbol GENERIC_CLOCKEVENTS_MIGR gpio: Kconfig: drop unknown symbol 'CS5535_GPIO' leds: Kconfig: Fix typo 'D2NET_V2' sound: Kconfig: drop unknown symbol ARCH_CLPS7500 ... Fix up trivial conflicts in arch/powerpc/platforms/40x/Kconfig (some new kconfig additions, close to removed commented-out old ones)
2011-12-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: net/bluetooth/l2cap_core.c Just two overlapping changes, one added an initialization of a local variable, and another change added a new local variable. Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-20sctp: Do not account for sizeof(struct sk_buff) in estimated rwndThomas Graf
When checking whether a DATA chunk fits into the estimated rwnd a full sizeof(struct sk_buff) is added to the needed chunk size. This quickly exhausts the available rwnd space and leads to packets being sent which are much below the PMTU limit. This can lead to much worse performance. The reason for this behaviour was to avoid putting too much memory pressure on the receiver. The concept is not completely irational because a Linux receiver does in fact clone an skb for each DATA chunk delivered. However, Linux also reserves half the available socket buffer space for data structures therefore usage of it is already accounted for. When proposing to change this the last time it was noted that this behaviour was introduced to solve a performance issue caused by rwnd overusage in combination with small DATA chunks. Trying to reproduce this I found that with the sk_buff overhead removed, the performance would improve significantly unless socket buffer limits are increased. The following numbers have been gathered using a patched iperf s