linux-stable.git/net/core/rtnetlink.c, branch v6.10

rtnetlink: make the "split" NLM_DONE handling generic

2024-06-05T11:34:54+00:00

Jaroslav reports Dell's OMSA Systems Management Data Engine
expects NLM_DONE in a separate recvmsg(), both for rtnl_dump_ifinfo()
and inet_dump_ifaddr(). We already added a similar fix previously in
commit 460b0d33cf10 ("inet: bring NLM_DONE out to a separate recv() again")

Instead of modifying all the dump handlers, and making them look
different than modern for_each_netdev_dump()-based dump handlers -
put the workaround in rtnetlink code. This will also help us move
the custom rtnl-locking from af_netlink in the future (in net-next).

Note that this change is not touching rtnl_dump_all(). rtnl_dump_all()
is different kettle of fish and a potential problem. We now mix families
in a single recvmsg(), but NLM_DONE is not coalesced.

Tested:

  ./cli.py --dbg-small-recv 4096 --spec netlink/specs/rt_addr.yaml \
           --dump getaddr --json '{"ifa-family": 2}'

  ./cli.py --dbg-small-recv 4096 --spec netlink/specs/rt_route.yaml \
           --dump getroute --json '{"rtm-family": 2}'

  ./cli.py --dbg-small-recv 4096 --spec netlink/specs/rt_link.yaml \
           --dump getlink

Fixes: 3e41af90767d ("rtnetlink: use xarray iterator to implement rtnl_dump_ifinfo()")
Fixes: cdb2f80f1c10 ("inet: use xa_array iterator to implement inet_dump_ifaddr()")
Reported-by: Jaroslav Pulchart 
Link: https://lore.kernel.org/all/CAK8fFZ7MKoFSEzMBDAOjoUt+vTZRRQgLDNXEOfdCCXSoXXKE0g@mail.gmail.com
Signed-off-by: Jakub Kicinski 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller

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

2024-05-09T17:01:01+00:00

Cross-merge networking fixes after downstream PR.

No conflicts.

Adjacent changes:

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
  35d92abfbad8 ("net: hns3: fix kernel crash when devlink reload during initialization")
  2a1a1a7b5fd7 ("net: hns3: add command queue trace for hns3")

Signed-off-by: Jakub Kicinski

rtnetlink: allow rtnl_fill_link_netnsid() to run under RCU protection

2024-05-07T09:14:50+00:00

We want to be able to run rtnl_fill_ifinfo() under RCU protection
instead of RTNL in the future.

All rtnl_link_ops->get_link_net() methods already using dev_net()
are ready. I added READ_ONCE() annotations on others.

Signed-off-by: Eric Dumazet 
Reviewed-by: Simon Horman 
Signed-off-by: Paolo Abeni

rtnetlink: do not depend on RTNL in rtnl_xdp_prog_skb()

2024-05-07T09:14:50+00:00

dev->xdp_prog is protected by RCU, we can lift RTNL requirement
from rtnl_xdp_prog_skb().

Signed-off-by: Eric Dumazet 
Reviewed-by: Simon Horman 
Signed-off-by: Paolo Abeni

rtnetlink: do not depend on RTNL in rtnl_fill_proto_down()

2024-05-07T09:14:50+00:00

Change dev_change_proto_down() and dev_change_proto_down_reason()
to write once on dev->proto_down and dev->proto_down_reason.

Then rtnl_fill_proto_down() can use READ_ONCE() annotations
and run locklessly.

rtnl_proto_down_size() should assume worst case,
because readng dev->proto_down_reason multiple
times would be racy without RTNL in the future.

Signed-off-by: Eric Dumazet 
Reviewed-by: Simon Horman 
Signed-off-by: Paolo Abeni

rtnetlink: do not depend on RTNL for many attributes

2024-05-07T09:14:50+00:00

Following device fields can be read locklessly
in rtnl_fill_ifinfo() :

type, ifindex, operstate, link_mode, mtu, min_mtu, max_mtu, group,
promiscuity, allmulti, num_tx_queues, gso_max_segs, gso_max_size,
gro_max_size, gso_ipv4_max_size, gro_ipv4_max_size, tso_max_size,
tso_max_segs, num_rx_queues.

Signed-off-by: Eric Dumazet 
Signed-off-by: Paolo Abeni

rtnetlink: do not depend on RTNL for IFLA_TXQLEN output

2024-05-07T09:14:50+00:00

rtnl_fill_ifinfo() can read dev->tx_queue_len locklessly,
granted we add corresponding READ_ONCE()/WRITE_ONCE() annotations.

Add missing READ_ONCE(dev->tx_queue_len) in teql_enqueue()

Signed-off-by: Eric Dumazet 
Signed-off-by: Paolo Abeni

rtnetlink: do not depend on RTNL for IFLA_IFNAME output

2024-05-07T09:14:50+00:00

We can use netdev_copy_name() to no longer rely on RTNL
to fetch dev->name.

Signed-off-by: Eric Dumazet 
Reviewed-by: Simon Horman 
Signed-off-by: Paolo Abeni

rtnetlink: do not depend on RTNL for IFLA_QDISC output

2024-05-07T09:14:50+00:00

dev->qdisc can be read using RCU protection.

Signed-off-by: Eric Dumazet 
Reviewed-by: Simon Horman 
Signed-off-by: Paolo Abeni

rtnetlink: Correct nested IFLA_VF_VLAN_LIST attribute validation

2024-05-03T22:57:50+00:00

Each attribute inside a nested IFLA_VF_VLAN_LIST is assumed to be a
struct ifla_vf_vlan_info so the size of such attribute needs to be at least
of sizeof(struct ifla_vf_vlan_info) which is 14 bytes.
The current size validation in do_setvfinfo is against NLA_HDRLEN (4 bytes)
which is less than sizeof(struct ifla_vf_vlan_info) so this validation
is not enough and a too small attribute might be cast to a
struct ifla_vf_vlan_info, this might result in an out of bands
read access when accessing the saved (casted) entry in ivvl.

Fixes: 79aab093a0b5 ("net: Update API for VF vlan protocol 802.1ad support")
Signed-off-by: Roded Zats 
Reviewed-by: Donald Hunter 
Link: https://lore.kernel.org/r/20240502155751.75705-1-rzats@paloaltonetworks.com
Signed-off-by: Jakub Kicinski