kernel.git/net/mctp, branch linux-6.15.y

net: mctp: Prevent duplicate binds

2025-08-20T16:36:04Z

[ Upstream commit 3954502377ec05a1b37e2dc9bef0bacd4bbd71b2 ] Disallow bind() calls that have the same arguments as existing bound sockets. Previously multiple sockets could bind() to the same type/local address, with an arbitrary socket receiving matched messages. This is only a partial fix, a future commit will define precedence order for MCTP_ADDR_ANY versus specific EID bind(), which are allowed to exist together. Signed-off-by: Matt Johnston Link: https://patch.msgid.link/20250710-mctp-bind-v4-2-8ec2f6460c56@codeconstruct.com.au Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net: mctp: Ensure keys maintain only one ref to corresponding dev

2025-05-09T23:22:53Z

mctp_flow_prepare_output() is called in mctp_route_output(), which places outbound packets onto a given interface. The packet may represent a message fragment, in which case we provoke an unbalanced reference count to the underlying device. This causes trouble if we ever attempt to remove the interface: [ 48.702195] usb 1-1: USB disconnect, device number 2 [ 58.883056] unregister_netdevice: waiting for mctpusb0 to become free. Usage count = 2 [ 69.022548] unregister_netdevice: waiting for mctpusb0 to become free. Usage count = 2 [ 79.172568] unregister_netdevice: waiting for mctpusb0 to become free. Usage count = 2 ... Predicate the invocation of mctp_dev_set_key() in mctp_flow_prepare_output() on not already having associated the device with the key. It's not yet realistic to uphold the property that the key maintains only one device reference earlier in the transmission sequence as the route (and therefore the device) may not be known at the time the key is associated with the socket. Fixes: 67737c457281 ("mctp: Pass flow data & flow release events to drivers") Acked-by: Jeremy Kerr Signed-off-by: Andrew Jeffery Link: https://patch.msgid.link/20250508-mctp-dev-refcount-v1-1-d4f965c67bb5@codeconstruct.com.au Signed-off-by: Jakub Kicinski

net: mctp: Don't access ifa_index when missing

2025-05-09T22:03:53Z

In mctp_dump_addrinfo, ifa_index can be used to filter interfaces, but only when the struct ifaddrmsg is provided. Otherwise it will be comparing to uninitialised memory - reproducible in the syzkaller case from dhcpd, or busybox "ip addr show". The kernel MCTP implementation has always filtered by ifa_index, so existing userspace programs expecting to dump MCTP addresses must already be passing a valid ifa_index value (either 0 or a real index). BUG: KMSAN: uninit-value in mctp_dump_addrinfo+0x208/0xac0 net/mctp/device.c:128 mctp_dump_addrinfo+0x208/0xac0 net/mctp/device.c:128 rtnl_dump_all+0x3ec/0x5b0 net/core/rtnetlink.c:4380 rtnl_dumpit+0xd5/0x2f0 net/core/rtnetlink.c:6824 netlink_dump+0x97b/0x1690 net/netlink/af_netlink.c:2309 Fixes: 583be982d934 ("mctp: Add device handling and netlink interface") Reported-by: syzbot+e76d52dadc089b9d197f@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/68135815.050a0220.3a872c.000e.GAE@google.com/ Reported-by: syzbot+1065a199625a388fce60@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/681357d6.050a0220.14dd7d.000d.GAE@google.com/ Signed-off-by: Matt Johnston Link: https://patch.msgid.link/20250508-mctp-addr-dump-v2-1-c8a53fd2dd66@codeconstruct.com.au Signed-off-by: Jakub Kicinski

net: mctp: Set SOCK_RCU_FREE

2025-04-12T01:42:34Z

Bind lookup runs under RCU, so ensure that a socket doesn't go away in the middle of a lookup. Fixes: 833ef3b91de6 ("mctp: Populate socket implementation") Signed-off-by: Matt Johnston Link: https://patch.msgid.link/20250410-mctp-rcu-sock-v1-1-872de9fdc877@codeconstruct.com.au Signed-off-by: Jakub Kicinski

treewide: Switch/rename to timer_delete[_sync]()

2025-04-05T08:30:12Z

timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree over and remove the historical wrapper inlines. Conversion was done with coccinelle plus manual fixups where necessary. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar

net: mctp: unshare packets when reassembling

2025-03-11T12:12:19Z

Ensure that the frag_list used for reassembly isn't shared with other packets. This avoids incorrect reassembly when packets are cloned, and prevents a memory leak due to circular references between fragments and their skb_shared_info. The upcoming MCTP-over-USB driver uses skb_clone which can trigger the problem - other MCTP drivers don't share SKBs. A kunit test is added to reproduce the issue. Signed-off-by: Matt Johnston Fixes: 4a992bbd3650 ("mctp: Implement message fragmentation & reassembly") Reviewed-by: Simon Horman Link: https://patch.msgid.link/20250306-matt-mctp-usb-v1-1-085502b3dd28@codeconstruct.com.au Signed-off-by: Paolo Abeni

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

2024-12-19T19:35:07Z

Cross-merge networking fixes after downstream PR (net-6.13-rc4). No conflicts. Adjacent changes: drivers/net/ethernet/renesas/rswitch.h 32fd46f5b69e ("net: renesas: rswitch: remove speed from gwca structure") 922b4b955a03 ("net: renesas: rswitch: rework ts tags management") Signed-off-by: Jakub Kicinski

net: mctp: handle skb cleanup on sock_queue failures

2024-12-19T10:52:49Z

Currently, we don't use the return value from sock_queue_rcv_skb, which means we may leak skbs if a message is not successfully queued to a socket. Instead, ensure that we're freeing the skb where the sock hasn't otherwise taken ownership of the skb by adding checks on the sock_queue_rcv_skb() to invoke a kfree on failure. In doing so, rather than using the 'rc' value to trigger the kfree_skb(), use the skb pointer itself, which is more explicit. Also, add a kunit test for the sock delivery failure cases. Fixes: 4a992bbd3650 ("mctp: Implement message fragmentation & reassembly") Cc: stable@vger.kernel.org Signed-off-by: Jeremy Kerr Link: https://patch.msgid.link/20241218-mctp-next-v2-1-1c1729645eaa@codeconstruct.com.au Signed-off-by: Paolo Abeni

mctp: no longer rely on net->dev_index_head[]

2024-12-09T22:29:14Z

mctp_dump_addrinfo() is one of the last users of net->dev_index_head[] in the control path. Switch to for_each_netdev_dump() for better scalability. Use C99 for mctp_device_rtnl_msg_handlers[] to prepare future RTNL removal from mctp_dump_addrinfo() (mdev->addrs is not yet RCU protected) Signed-off-by: Eric Dumazet Cc: Matt Johnston Reviewed-by: Kuniyuki Iwashima Acked-by: Jeremy Kerr Link: https://patch.msgid.link/20241206223811.1343076-1-edumazet@google.com Signed-off-by: Jakub Kicinski

net: mctp: Expose transport binding identifier via IFLA attribute

2024-11-09T17:04:54Z

MCTP control protocol implementations are transport binding dependent. Endpoint discovery is mandatory based on transport binding. Message timing requirements are specified in each respective transport binding specification. However, we currently have no means to get this information from MCTP links. Add a IFLA_MCTP_PHYS_BINDING netlink link attribute, which represents the transport type using the DMTF DSP0239-defined type numbers, returned as part of RTM_GETLINK data. We get an IFLA_MCTP_PHYS_BINDING attribute for each MCTP link, for example: - 0x00 (unspec) for loopback interface; - 0x01 (SMBus/I2C) for mctpi2c%d interfaces; and - 0x05 (serial) for mctpserial%d interfaces. Signed-off-by: Khang Nguyen Reviewed-by: Matt Johnston Link: https://patch.msgid.link/20241105071915.821871-1-khangng@os.amperecomputing.com Signed-off-by: Jakub Kicinski