kernel/include/net/sctp/structs.h, branch linux-4.16.y

Merge tag 'usercopy-v4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

2018-02-04T00:25:42Z

Pull hardened usercopy whitelisting from Kees Cook: "Currently, hardened usercopy performs dynamic bounds checking on slab cache objects. This is good, but still leaves a lot of kernel memory available to be copied to/from userspace in the face of bugs. To further restrict what memory is available for copying, this creates a way to whitelist specific areas of a given slab cache object for copying to/from userspace, allowing much finer granularity of access control. Slab caches that are never exposed to userspace can declare no whitelist for their objects, thereby keeping them unavailable to userspace via dynamic copy operations. (Note, an implicit form of whitelisting is the use of constant sizes in usercopy operations and get_user()/put_user(); these bypass all hardened usercopy checks since these sizes cannot change at runtime.) This new check is WARN-by-default, so any mistakes can be found over the next several releases without breaking anyone's system. The series has roughly the following sections: - remove %p and improve reporting with offset - prepare infrastructure and whitelist kmalloc - update VFS subsystem with whitelists - update SCSI subsystem with whitelists - update network subsystem with whitelists - update process memory with whitelists - update per-architecture thread_struct with whitelists - update KVM with whitelists and fix ioctl bug - mark all other allocations as not whitelisted - update lkdtm for more sensible test overage" * tag 'usercopy-v4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (38 commits) lkdtm: Update usercopy tests for whitelisting usercopy: Restrict non-usercopy caches to size 0 kvm: x86: fix KVM_XEN_HVM_CONFIG ioctl kvm: whitelist struct kvm_vcpu_arch arm: Implement thread_struct whitelist for hardened usercopy arm64: Implement thread_struct whitelist for hardened usercopy x86: Implement thread_struct whitelist for hardened usercopy fork: Provide usercopy whitelisting for task_struct fork: Define usercopy region in thread_stack slab caches fork: Define usercopy region in mm_struct slab caches net: Restrict unwhitelisted proto caches to size 0 sctp: Copy struct sctp_sock.autoclose to userspace using put_user() sctp: Define usercopy region in SCTP proto slab cache caif: Define usercopy region in caif proto slab cache ip: Define usercopy region in IP proto slab cache net: Define usercopy region in struct proto slab cache scsi: Define usercopy region in scsi_sense_cache slab cache cifs: Define usercopy region in cifs_request slab cache vxfs: Define usercopy region in vxfs_inode slab cache ufs: Define usercopy region in ufs_inode_cache slab cache ...

sctp: Define usercopy region in SCTP proto slab cache

2018-01-15T20:08:00Z

The SCTP socket event notification subscription information need to be copied to/from userspace. In support of usercopy hardening, this patch defines a region in the struct proto slab cache in which userspace copy operations are allowed. Additionally moves the usercopy fields to be adjacent for the region to cover both. example usage trace: net/sctp/socket.c: sctp_getsockopt_events(...): ... copy_to_user(..., &sctp_sk(sk)->subscribe, len) sctp_setsockopt_events(...): ... copy_from_user(&sctp_sk(sk)->subscribe, ..., optlen) sctp_getsockopt_initmsg(...): ... copy_to_user(..., &sctp_sk(sk)->initmsg, len) This region is known as the slab cache's usercopy region. Slab caches can now check that each dynamically sized copy operation involving cache-managed memory falls entirely within the slab's usercopy region. This patch is modified from Brad Spengler/PaX Team's PAX_USERCOPY whitelisting code in the last public patch of grsecurity/PaX based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. Signed-off-by: David Windsor [kees: split from network patch, move struct members adjacent] [kees: add SCTPv6 struct whitelist, provide usage trace] Cc: Vlad Yasevich Cc: Neil Horman Cc: "David S. Miller" Cc: linux-sctp@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2018-01-09T15:37:00Z

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

2018-01-08T19:19:13Z

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

sctp: implement validate_ftsn for sctp_stream_interleave

2017-12-15T18:52:22Z

validate_ftsn is added as a member of sctp_stream_interleave, used to validate ssn/chunk type for fwdtsn or mid (message id)/chunk type for ifwdtsn, called in sctp_sf_eat_fwd_tsn, just as validate_data. If this check fails, an abort packet will be sent, as said in section 2.3.1 of RFC8260. As ifwdtsn and fwdtsn chunks have different length, it also defines ftsn_chunk_len for sctp_stream_interleave to describe the chunk size. Then it replaces all sizeof(struct sctp_fwdtsn_chunk) with sctp_ftsnchk_len. It also adds the process for ifwdtsn in rx path. As Marcelo pointed out, there's no need to add event table for ifwdtsn, but just share prsctp_chunk_event_table with fwdtsn's. It would drop fwdtsn chunk for ifwdtsn and drop ifwdtsn chunk for fwdtsn by calling validate_ftsn in sctp_sf_eat_fwd_tsn. After this patch, the ifwdtsn can be accepted. Note that this patch also removes the sctp.intl_enable check for idata chunks in sctp_chunk_event_lookup, as it will do this check in validate_data later. Signed-off-by: Xin Long Acked-by: Marcelo R. Leitner Signed-off-by: David S. Miller

sctp: implement generate_ftsn for sctp_stream_interleave

2017-12-15T18:52:21Z

generate_ftsn is added as a member of sctp_stream_interleave, used to create fwdtsn or ifwdtsn chunk according to abandoned chunks, called in sctp_retransmit and sctp_outq_sack. sctp_generate_iftsn works for ifwdtsn, and sctp_generate_fwdtsn is still used for making fwdtsn. Signed-off-by: Xin Long Acked-by: Marcelo R. Leitner Signed-off-by: David S. Miller

sctp: add basic structures and make chunk function for ifwdtsn

2017-12-15T18:52:21Z

sctp_ifwdtsn_skip, sctp_ifwdtsn_hdr and sctp_ifwdtsn_chunk are used to define and parse I-FWD TSN chunk format, and sctp_make_ifwdtsn is a function to build the chunk. The I-FORWARD-TSN Chunk Format is defined in section 2.3.1 of RFC8260. Signed-off-by: Xin Long Acked-by: Marcelo R. Leitner Signed-off-by: David S. Miller

sctp: add support for the process of unordered idata

2017-12-11T16:23:05Z

Unordered idata process is more complicated than unordered data: - It has to add mid into sctp_stream_out to save the next mid value, which is separated from ordered idata's. - To support pd for unordered idata, another mid and pd_mode need to be added to save the message id and pd state in sctp_stream_in. - To make unordered idata reasm easier, it adds a new event queue to save frags for idata. The patch mostly adds the samilar reasm functions for unordered idata as ordered idata's, and also adjusts some other codes on assign_mid, abort_pd and ulpevent_data for idata. Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Acked-by: Neil Horman Signed-off-by: David S. Miller

sctp: implement ulpevent_data for sctp_stream_interleave

2017-12-11T16:23:05Z

ulpevent_data is added as a member of sctp_stream_interleave, used to do the most process in ulpq, including to convert data or idata chunk to event, reasm them in reasm queue and put them in lobby queue in right order, and deliver them up to user sk rx queue. This procedure is described in section 2.2.3 of RFC8260. It adds most functions for idata here to do the similar process as the old functions for data. But since the details are very different between them, the old functions can not be reused for idata. event->ssn and event->ppid settings are moved to ulpevent_data from sctp_ulpevent_make_rcvmsg, so that sctp_ulpevent_make_rcvmsg could work for both data and idata. Note that mid is added in sctp_ulpevent for idata, __packed has to be used for defining sctp_ulpevent, or it would exceeds the skb cb that saves a sctp_ulpevent variable for ulp layer process. Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Acked-by: Neil Horman Signed-off-by: David S. Miller

sctp: implement validate_data for sctp_stream_interleave

2017-12-11T16:23:04Z

validate_data is added as a member of sctp_stream_interleave, used to validate ssn/chunk type for data or mid (message id)/chunk type for idata, called in sctp_eat_data. If this check fails, an abort packet will be sent, as said in section 2.2.3 of RFC8260. It also adds the process for idata in rx path. As Marcelo pointed out, there's no need to add event table for idata, but just share chunk_event_table with data's. It would drop data chunk for idata and drop idata chunk for data by calling validate_data in sctp_eat_data. As last patch did, it also replaces sizeof(struct sctp_data_chunk) with sctp_datachk_len for rx path. After this patch, the idata can be accepted and delivered to ulp layer. Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Acked-by: Neil Horman Signed-off-by: David S. Miller