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2023-10-11mctp: perform route lookups under a RCU read-side lockJeremy Kerr1-6/+16
Our current route lookups (mctp_route_lookup and mctp_route_lookup_null) traverse the net's route list without the RCU read lock held. This means the route lookup is subject to preemption, resulting in an potential grace period expiry, and so an eventual kfree() while we still have the route pointer. Add the proper read-side critical section locks around the route lookups, preventing premption and a possible parallel kfree. The remaining net->mctp.routes accesses are already under a rcu_read_lock, or protected by the RTNL for updates. Based on an analysis from Sili Luo <rootlab@huawei.com>, where introducing a delay in the route lookup could cause a UAF on simultaneous sendmsg() and route deletion. Reported-by: Sili Luo <rootlab@huawei.com> Fixes: 889b7da23abf ("mctp: Add initial routing framework") Cc: stable@vger.kernel.org Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/29c4b0e67dc1bf3571df3982de87df90cae9b631.1696837310.git.jk@codeconstruct.com.au Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-17net: mctp: remove redundant RTN_UNICAST checkLin Ma1-3/+0
Current mctp_newroute() contains two exactly same check against rtm->rtm_type static int mctp_newroute(...) { ... if (rtm->rtm_type != RTN_UNICAST) { // (1) NL_SET_ERR_MSG(extack, "rtm_type must be RTN_UNICAST"); return -EINVAL; } ... if (rtm->rtm_type != RTN_UNICAST) // (2) return -EINVAL; ... } This commits removes the (2) check as it is redundant. Signed-off-by: Lin Ma <linma@zju.edu.cn> Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com> Acked-by: Jeremy Kerr <jk@codeconstruct.com.au> Link: https://lore.kernel.org/r/20230615152240.1749428-1-linma@zju.edu.cn Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-01-25net: mctp: mark socks as dead on unhash, prevent re-addJeremy Kerr1-0/+6
Once a socket has been unhashed, we want to prevent it from being re-used in a sk_key entry as part of a routing operation. This change marks the sk as SOCK_DEAD on unhash, which prevents addition into the net's key list. We need to do this during the key add path, rather than key lookup, as we release the net keys_lock between those operations. Fixes: 4a992bbd3650 ("mctp: Implement message fragmentation & reassembly") Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-01-25net: mctp: hold key reference when looking up a general keyPaolo Abeni1-7/+7
Currently, we have a race where we look up a sock through a "general" (ie, not directly associated with the (src,dest,tag) tuple) key, then drop the key reference while still holding the key's sock. This change expands the key reference until we've finished using the sock, and hence the sock reference too. Commit message changes from Jeremy Kerr <jk@codeconstruct.com.au>. Reported-by: Noam Rathaus <noamr@ssd-disclosure.com> Fixes: 73c618456dc5 ("mctp: locking, lifetime and validity changes for sk_keys") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-01-25net: mctp: add an explicit reference from a mctp_sk_key to sockJeremy Kerr1-6/+8
Currently, we correlate the mctp_sk_key lifetime to the sock lifetime through the sock hash/unhash operations, but this is pretty tenuous, and there are cases where we may have a temporary reference to an unhashed sk. This change makes the reference more explicit, by adding a hold on the sock when it's associated with a mctp_sk_key, released on final key unref. Fixes: 73c618456dc5 ("mctp: locking, lifetime and validity changes for sk_keys") Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-11-10mctp: Fix an error handling path in mctp_init()Wei Yongjun1-1/+1
If mctp_neigh_init() return error, the routes resources should be released in the error handling path. Otherwise some resources leak. Fixes: 4d8b9319282a ("mctp: Add neighbour implementation") Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Acked-by: Matt Johnston <matt@codeconstruct.com.au> Link: https://lore.kernel.org/r/20221108095517.620115-1-weiyongjun@huaweicloud.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-12mctp: prevent double key removal and unrefJeremy Kerr1-5/+5
Currently, we have a bug where a simultaneous DROPTAG ioctl and socket close may race, as we attempt to remove a key from lists twice, and perform an unref for each removal operation. This may result in a uaf when we attempt the second unref. This change fixes the race by making __mctp_key_remove tolerant to being called on a key that has already been removed from the socket/net lists, and only performs the unref when we do the actual remove. We also need to hold the list lock on the ioctl cleanup path. This fix is based on a bug report and comprehensive analysis from butt3rflyh4ck <butterflyhuangxx@gmail.com>, found via syzkaller. Cc: stable@vger.kernel.org Fixes: 63ed1aab3d40 ("mctp: Add SIOCMCTP{ALLOC,DROP}TAG ioctls for tag control") Reported-by: butt3rflyh4ck <butterflyhuangxx@gmail.com> Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-04-01mctp: Use output netdev to allocate skb headroomMatt Johnston1-3/+11
Previously the skb was allocated with headroom MCTP_HEADER_MAXLEN, but that isn't sufficient if we are using devs that are not MCTP specific. This also adds a check that the smctp_halen provided to sendmsg for extended addressing is the correct size for the netdev. Fixes: 833ef3b91de6 ("mctp: Populate socket implementation") Reported-by: Matthew Rinaldi <mjrinal@g.clemson.edu> Signed-off-by: Matt Johnston <matt@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-04-01mctp: Fix check for dev_hard_header() resultMatt Johnston1-1/+1
dev_hard_header() returns the length of the header, so we need to test for negative errors rather than non-zero. Fixes: 889b7da23abf ("mctp: Add initial routing framework") Signed-off-by: Matt Johnston <matt@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-23mctp: Fix warnings reported by clang-analyzerMatt Johnston1-1/+0
net/mctp/device.c:140:11: warning: Assigned value is garbage or undefined [clang-analyzer-core.uninitialized.Assign] mcb->idx = idx; - Not a real problem due to how the callback runs, fix the warning. net/mctp/route.c:458:4: warning: Value stored to 'msk' is never read [clang-analyzer-deadcode.DeadStores] msk = container_of(key->sk, struct mctp_sock, sk); - 'msk' dead assignment can be removed here. Signed-off-by: Matt Johnston <matt@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-23mctp: Fix incorrect netdev unref for extended addrMatt Johnston1-6/+2
In the extended addressing local route output codepath dev_get_by_index_rcu() doesn't take a dev_hold() so we shouldn't dev_put(). Signed-off-by: Matt Johnston <matt@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-23mctp: make __mctp_dev_get() take a refcount holdMatt Johnston1-1/+4
Previously there was a race that could allow the mctp_dev refcount to hit zero: rcu_read_lock(); mdev = __mctp_dev_get(dev); // mctp_unregister() happens here, mdev->refs hits zero mctp_dev_hold(dev); rcu_read_unlock(); Now we make __mctp_dev_get() take the hold itself. It is safe to test against the zero refcount because __mctp_dev_get() is called holding rcu_read_lock and mctp_dev uses kfree_rcu(). Reported-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Matt Johnston <matt@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-19mctp: add address validity checking for packet receiveJeremy Kerr1-0/+11
This change adds some basic sanity checks for the source and dest headers of packets on initial receive. Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-19mctp: replace mctp_address_ok with more fine-grained helpersJeremy Kerr1-1/+1
Currently, we have mctp_address_ok(), which checks if an EID is in the "valid" range of 8-254 inclusive. However, 0 and 255 may also be valid addresses, depending on context. 0 is the NULL EID, which may be set when physical addressing is used. 255 is valid as a destination address for broadcasts. This change renames mctp_address_ok to mctp_address_unicast, and adds similar helpers for broadcast and null EIDs, which will be used in an upcoming commit. Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-17Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-5/+6
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-15mctp: fix use after freeTom Rix1-5/+6
Clang static analysis reports this problem route.c:425:4: warning: Use of memory after it is freed trace_mctp_key_acquire(key); ^~~~~~~~~~~~~~~~~~~~~~~~~~~ When mctp_key_add() fails, key is freed but then is later used in trace_mctp_key_acquire(). Add an else statement to use the key only when mctp_key_add() is successful. Fixes: 4f9e1ba6de45 ("mctp: Add tracepoints for tag/key handling") Signed-off-by: Tom Rix <trix@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-09mctp: Add SIOCMCTP{ALLOC,DROP}TAG ioctls for tag controlMatt Johnston1-28/+86
This change adds a couple of new ioctls for mctp sockets: SIOCMCTPALLOCTAG and SIOCMCTPDROPTAG. These ioctls provide facilities for explicit allocation / release of tags, overriding the automatic allocate-on-send/release-on-reply and timeout behaviours. This allows userspace more control over messages that may not fit a simple request/response model. In order to indicate a pre-allocated tag to the sendmsg() syscall, we introduce a new flag to the struct sockaddr_mctp.smctp_tag value: MCTP_TAG_PREALLOC. Additional changes from Jeremy Kerr <jk@codeconstruct.com.au>. Contains a fix that was: Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Matt Johnston <matt@codeconstruct.com.au> Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-09mctp: Allow keys matching any local addressJeremy Kerr1-2/+2
Currently, we require an exact match on an incoming packet's dest address, and the key's local_addr field. In a future change, we may want to set up a key before packets are routed, meaning we have no local address to match on. This change allows key lookups to match on local_addr = MCTP_ADDR_ANY. Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-09mctp: Add helper for address match checkingJeremy Kerr1-5/+3
Currently, we have a couple of paths that check that an EID matches, or the match value is MCTP_ADDR_ANY. Rather than open coding this, add a little helper. Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-4/+5
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-02mctp: Remove redundant if statementsXu Wang1-2/+1
The 'if (dev)' statement already move into dev_{put , hold}, so remove redundant if statements. Signed-off-by: Xu Wang <vulab@iscas.ac.cn> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-02mctp: Don't let RTM_DELROUTE delete local routesMatt Johnston1-4/+5
We need to test against the existing route type, not the rtm_type in the netlink request. Fixes: 83f0a0b7285b ("mctp: Specify route types, require rtm_type in RTM_*ROUTE messages") Signed-off-by: Matt Johnston <matt@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-01mctp: remove unnecessary check before calling kfree_skb()Yang Yingliang1-3/+1
The skb will be checked inside kfree_skb(), so remove the outside check. Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Link: https://lore.kernel.org/r/20211130031243.768823-1-yangyingliang@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-10-29mctp: Pass flow data & flow release events to driversJeremy Kerr1-2/+53
Now that we have an extension for MCTP data in skbs, populate the flow when a key has been created for the packet, and add a device driver operation to inform of flow destruction. Includes a fix for a warning with test builds: Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-29mctp: Return new key from mctp_alloc_local_tagJeremy Kerr1-12/+16
In a future change, we will want the key available for future use after allocating a new tag. This change returns the key from mctp_alloc_local_tag, rather than just key->tag. Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-26mctp: Implement extended addressingJeremy Kerr1-25/+73
This change allows an extended address struct - struct sockaddr_mctp_ext - to be passed to sendmsg/recvmsg. This allows userspace to specify output ifindex and physical address information (for sendmsg) or receive the input ifindex/physaddr for incoming messages (for recvmsg). This is typically used by userspace for MCTP address discovery and assignment operations. The extended addressing facility is conditional on a new sockopt: MCTP_OPT_ADDR_EXT; userspace must explicitly enable addressing before the kernel will consume/populate the extended address data. Includes a fix for an uninitialised var: Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-15mctp: Avoid leak of mctp_sk_keyMatt Johnston1-0/+4
mctp_key_alloc() returns a key already referenced. The mctp_route_input() path receives a packet for a bind socket and allocates a key. It passes the key to mctp_key_add() which takes a refcount and adds the key to lists. mctp_route_input() should then release its own refcount when setting the key pointer to NULL. In the mctp_alloc_local_tag() path (for mctp_local_output()) we similarly need to unref the key before returning (mctp_reserve_tag() takes a refcount and adds the key to lists). Fixes: 73c618456dc5 ("mctp: locking, lifetime and validity changes for sk_keys") Signed-off-by: Matt Johnston <matt@codeconstruct.com.au> Reviewed-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-03mctp: Add initial test structure and fragmentation testJeremy Kerr1-0/+5
This change adds the first kunit test for the mctp subsystem, and an initial test for the fragmentation path. We're adding tests under a new net/mctp/test/ directory. Incorporates a fix for module configs: Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-01Revert "Merge branch 'mctp-kunit-tests'"David S. Miller1-5/+0
This reverts commit 4f42ad2011d2fcbd89f5cdf56121271a8cd5ee5d, reversing changes made to ea2dd331bfaaeba74ba31facf437c29044f7d4cb. These chanfges break the build when mctp is modular. Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-01mctp: Add initial test structure and fragmentation testJeremy Kerr1-0/+5
This change adds the first kunit test for the mctp subsystem, and an initial test for the fragmentation path. We're adding tests under a new net/mctp/test/ directory. Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-29mctp: Set route MTU via netlinkMatt Johnston1-1/+13
A route's RTAX_MTU can be set in nested RTAX_METRICS Signed-off-by: Matt Johnston <matt@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-29mctp: Add tracepoints for tag/key handlingJeremy Kerr1-1/+11
The tag allocation, release and bind events are somewhat opaque outside the kernel; this change adds a few tracepoints to assist in instrumentation and debugging. Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-29mctp: Implement a timeout for tagsJeremy Kerr1-0/+8
Currently, a MCTP (local-eid,remote-eid,tag) tuple is allocated to a socket on send, and only expires when the socket is closed. This change introduces a tag timeout, freeing the tuple after a fixed expiry - currently six seconds. This is greater than (but close to) the max response timeout in upper-layer bindings. Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-29mctp: Add refcounts to mctp_devJeremy Kerr1-2/+2
Currently, we tie the struct mctp_dev lifetime to the underlying struct net_device, and hold/put that device as a proxy for a separate mctp_dev refcount. This works because we're not holding any references to the mctp_dev that are different from the netdev lifetime. In a future change we'll break that assumption though, as we'll need to hold mctp_dev references in a workqueue, which might live past the netdev unregister notification. In order to support that, this change introduces a refcount on the mctp_dev, currently taken by the net_device->mctp_ptr reference, and released on netdev unregister events. We can then use this for future references that might outlast the net device. Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-29mctp: locking, lifetime and validity changes for sk_keysJeremy Kerr1-31/+87
We will want to invalidate sk_keys in a future change, which will require a boolean flag to mark invalidated items in the socket & net namespace lists. We'll also need to take a reference to keys, held over non-atomic contexts, so we need a refcount on keys also. This change adds a validity flag (currently always true) and refcount to struct mctp_sk_key. With a refcount on the keys, using RCU no longer makes much sense; we have exact indications on the lifetime of keys. So, we also change the RCU list traversal to a locked implementation. Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-29mctp: Allow local delivery to the null EIDJeremy Kerr1-0/+23
We may need to receive packets addressed to the null EID (==0), but addressed to us at the physical layer. This change adds a lookup for local routes when we see a packet addressed to EID 0, and a local phys address. Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-29mctp: Allow MCTP on tun devicesMatt Johnston1-5/+8
Allowing TUN is useful for testing, to route packets to userspace or to tunnel between machines. Signed-off-by: Matt Johnston <matt@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-08mctp: perform route destruction under RCU read lockJeremy Kerr1-0/+2
The kernel test robot reports: [ 843.509974][ T345] ============================= [ 843.524220][ T345] WARNING: suspicious RCU usage [ 843.538791][ T345] 5.14.0-rc2-00606-g889b7da23abf #1 Not tainted [ 843.553617][ T345] ----------------------------- [ 843.567412][ T345] net/mctp/route.c:310 RCU-list traversed in non-reader section!! - we're missing the rcu read lock acquire around the destruction path. This change adds the acquire/release - the path is already atomic, and we're using the _rcu list iterators. Reported-by: kernel test robot <oliver.sang@intel.com> Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-12mctp: Specify route types, require rtm_type in RTM_*ROUTE messagesJeremy Kerr1-5/+22
This change adds a 'type' attribute to routes, which can be parsed from a RTM_NEWROUTE message. This will help to distinguish local vs. peer routes in a future change. This means userspace will need to set a correct rtm_type in RTM_NEWROUTE and RTM_DELROUTE messages; we currently only accept RTN_UNICAST. Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Link: https://lore.kernel.org/r/20210810023834.2231088-1-jk@codeconstruct.com.au Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-07-29mctp: Allow per-netns default networksMatt Johnston1-0/+14
Currently we have a compile-time default network (MCTP_INITIAL_DEFAULT_NET). This change introduces a default_net field on the net namespace, allowing future configuration for new interfaces. Signed-off-by: Matt Johnston <matt@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-29mctp: Add dest neighbour lladdr to route outputMatt Johnston1-2/+8
Now that we have a neighbour implementation, hook it up to the output path to set the dest hardware address for outgoing packets. Signed-off-by: Matt Johnston <matt@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-29mctp: Implement message fragmentation & reassemblyJeremy Kerr1-41/+331
This change implements MCTP fragmentation (based on route & device MTU), and corresponding reassembly. The MCTP specification only allows for fragmentation on the originating message endpoint, and reassembly on the destination endpoint - intermediate nodes do not need to reassemble/refragment. Consequently, we only fragment in the local transmit path, and reassemble locally-bound packets. Messages are required to be in-order, so we simply cancel reassembly on out-of-order or missing packets. In the fragmentation path, we just break up the message into MTU-sized fragments; the skb structure is a simple copy for now, which we can later improve with a shared data implementation. For reassembly, we keep track of incoming message fragments using the existing tag infrastructure, allocating a key on the (src,dest,tag) tuple, and reassembles matching fragments into a skb->frag_list. Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-29mctp: Populate socket implementationJeremy Kerr1-3/+223
Start filling-out the socket syscalls: bind, sendmsg & recvmsg. This requires an input route implementation, so we add to mctp_route_input, allowing lookups on binds & message tags. This just handles single-packet messages at present, we will add fragmentation in a future change. Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-29mctp: Add netlink route managementMatt Johnston1-9/+249
This change adds RTM_GETROUTE, RTM_NEWROUTE & RTM_DELROUTE handlers, allowing management of the MCTP route table. Includes changes from Jeremy Kerr <jk@codeconstruct.com.au>. Signed-off-by: Matt Johnston <matt@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-29mctp: Add initial routing frameworkJeremy Kerr1-0/+329
Add a simple routing table, and a couple of route output handlers, and the mctp packet_type & handler. Includes changes from Matt Johnston <matt@codeconstruct.com.au>. Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>