linux-stable.git/net/mctp, branch linux-6.16.y

mctp: return -ENOPROTOOPT for unknown getsockopt options

2025-09-09T17:02:27+00:00

[ Upstream commit a125c8fb9ddbcb0602103a50727a476fd30dec01 ]

In mctp_getsockopt(), unrecognized options currently return -EINVAL.
In contrast, mctp_setsockopt() returns -ENOPROTOOPT for unknown
options.

Update mctp_getsockopt() to also return -ENOPROTOOPT for unknown
options. This aligns the behavior of getsockopt() and setsockopt(),
and matches the standard kernel socket API convention for handling
unsupported options.

Fixes: 99ce45d5e7db ("mctp: Implement extended addressing")
Signed-off-by: Alok Tiwari 
Link: https://patch.msgid.link/20250902102059.1370008-1-alok.a.tiwari@oracle.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

net: mctp: mctp_fraq_queue should take ownership of passed skb

2025-09-09T17:02:23+00:00

[ Upstream commit 773b27a8a2f00ce3134e92e50ea4794a98ba2b76 ]

As of commit f5d83cf0eeb9 ("net: mctp: unshare packets when
reassembling"), we skb_unshare() in mctp_frag_queue(). The unshare may
invalidate the original skb pointer, so we need to treat the skb as
entirely owned by the fraq queue, even on failure.

Fixes: f5d83cf0eeb9 ("net: mctp: unshare packets when reassembling")
Signed-off-by: Jeremy Kerr 
Link: https://patch.msgid.link/20250829-mctp-skb-unshare-v1-1-1c28fe10235a@codeconstruct.com.au
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin

net: mctp: Prevent duplicate binds

2025-08-20T16:41:08+00:00

[ 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: use nlmsg_payload() for netlink message data extraction

2025-05-26T15:38:27+00:00

Jakub suggests:

> I have a different request :) Matt, once this ends up in net-next
> (end of this week) could you refactor it to use nlmsg_payload() ?
> It doesn't exist in net but this is exactly why it was added.

This refactors the additions to both mctp_dump_addrinfo(), and
mctp_rtm_getneigh() - two cases where we're calling nlh_data() on an
an incoming netlink message, without a prior nlmsg_parse().

For the neigh.c case, we cannot hit the failure where the nlh does not
contain a full ndmsg at present, as the core handler
(net/core/neighbour.c, neigh_get()) has already validated the size
through neigh_valid_req_get(), and would have failed the get operation
before the MCTP hander is called.

However, relying on that is a bit fragile, so apply the nlmsg_payload
refector here too.

Reviewed-by: Simon Horman 
Signed-off-by: Jeremy Kerr 
Link: https://patch.msgid.link/20250521-mctp-nlmsg-payload-v2-1-e85df160c405@codeconstruct.com.au
Signed-off-by: Paolo Abeni

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

2025-05-09T23:22:53+00:00

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

2025-05-09T22:03:53+00:00

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

2025-04-12T01:42:34+00:00

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]()

2025-04-05T08:30:12+00:00

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

2025-03-11T12:12:19+00:00

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

2024-12-19T19:35:07+00:00

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