linux.git/net/netfilter, branch v6.2-rc5

netfilter: conntrack: handle tcp challenge acks during connection reuse

2023-01-17T22:00:06+00:00

When a connection is re-used, following can happen:
[ connection starts to close, fin sent in either direction ]
 > syn   # initator quickly reuses connection
 < ack   # peer sends a challenge ack
 > rst   # rst, sequence number == ack_seq of previous challenge ack
 > syn   # this syn is expected to pass

Problem is that the rst will fail window validation, so it gets
tagged as invalid.

If ruleset drops such packets, we get repeated syn-retransmits until
initator gives up or peer starts responding with syn/ack.

Before the commit indicated in the "Fixes" tag below this used to work:

The challenge-ack made conntrack re-init state based on the challenge
ack itself, so the following rst would pass window validation.

Add challenge-ack support: If we get ack for syn, record the ack_seq,
and then check if the rst sequence number matches the last ack number
seen in reverse direction.

Fixes: c7aab4f17021 ("netfilter: nf_conntrack_tcp: re-init for syn packets only")
Reported-by: Michal Tesar 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: nft_payload: incorrect arithmetics when fetching VLAN header bits

2023-01-11T18:18:04+00:00

If the offset + length goes over the ethernet + vlan header, then the
length is adjusted to copy the bytes that are within the boundaries of
the vlan_ethhdr scratchpad area. The remaining bytes beyond ethernet +
vlan header are copied directly from the skbuff data area.

Fix incorrect arithmetic operator: subtract, not add, the size of the
vlan header in case of double-tagged packets to adjust the length
accordingly to address CVE-2023-0179.

Reported-by: Davide Ornaghi 
Fixes: f6ae9f120dad ("netfilter: nft_payload: add C-VLAN support")
Signed-off-by: Pablo Neira Ayuso

netfilter: ipset: Fix overflow before widen in the bitmap_ip_create() function.

2023-01-11T18:18:04+00:00

When first_ip is 0, last_ip is 0xFFFFFFFF, and netmask is 31, the value of
an arithmetic expression 2 << (netmask - mask_bits - 1) is subject
to overflow due to a failure casting operands to a larger data type
before performing the arithmetic.

Note that it's harmless since the value will be checked at the next step.

Found by InfoTeCS on behalf of Linux Verification Center
(linuxtesting.org) with SVACE.

Fixes: b9fed748185a ("netfilter: ipset: Check and reject crazy /0 input parameters")
Signed-off-by: Ilia.Gavrilov 
Reviewed-by: Simon Horman 
Signed-off-by: Pablo Neira Ayuso

Merge tag 'net-6.2-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2023-01-05T20:40:50+00:00

Pull networking fixes from Jakub Kicinski:
 "Including fixes from bpf, wifi, and netfilter.

  Current release - regressions:

   - bpf: fix nullness propagation for reg to reg comparisons, avoid
     null-deref

   - inet: control sockets should not use current thread task_frag

   - bpf: always use maximal size for copy_array()

   - eth: bnxt_en: don't link netdev to a devlink port for VFs

  Current release - new code bugs:

   - rxrpc: fix a couple of potential use-after-frees

   - netfilter: conntrack: fix IPv6 exthdr error check

   - wifi: iwlwifi: fw: skip PPAG for JF, avoid FW crashes

   - eth: dsa: qca8k: various fixes for the in-band register access

   - eth: nfp: fix schedule in atomic context when sync mc address

   - eth: renesas: rswitch: fix getting mac address from device tree

   - mobile: ipa: use proper endpoint mask for suspend

  Previous releases - regressions:

   - tcp: add TIME_WAIT sockets in bhash2, fix regression caught by
     Jiri / python tests

   - net: tc: don't intepret cls results when asked to drop, fix
     oob-access

   - vrf: determine the dst using the original ifindex for multicast

   - eth: bnxt_en:
      - fix XDP RX path if BPF adjusted packet length
      - fix HDS (header placement) and jumbo thresholds for RX packets

   - eth: ice: xsk: do not use xdp_return_frame() on tx_buf->raw_buf,
     avoid memory corruptions

  Previous releases - always broken:

   - ulp: prevent ULP without clone op from entering the LISTEN status

   - veth: fix race with AF_XDP exposing old or uninitialized
     descriptors

   - bpf:
      - pull before calling skb_postpull_rcsum() (fix checksum support
        and avoid a WARN())
      - fix panic due to wrong pageattr of im->image (when livepatch and
        kretfunc coexist)
      - keep a reference to the mm, in case the task is dead

   - mptcp: fix deadlock in fastopen error path

   - netfilter:
      - nf_tables: perform type checking for existing sets
      - nf_tables: honor set timeout and garbage collection updates
      - ipset: fix hash:net,port,net hang with /0 subnet
      - ipset: avoid hung task warning when adding/deleting entries

   - selftests: net:
      - fix cmsg_so_mark.sh test hang on non-x86 systems
      - fix the arp_ndisc_evict_nocarrier test for IPv6

   - usb: rndis_host: secure rndis_query check against int overflow

   - eth: r8169: fix dmar pte write access during suspend/resume with
     WOL

   - eth: lan966x: fix configuration of the PCS

   - eth: sparx5: fix reading of the MAC address

   - eth: qed: allow sleep in qed_mcp_trace_dump()

   - eth: hns3:
      - fix interrupts re-initialization after VF FLR
      - fix handling of promisc when MAC addr table gets full
      - refine the handling for VF heartbeat

   - eth: mlx5:
      - properly handle ingress QinQ-tagged packets on VST
      - fix io_eq_size and event_eq_size params validation on big endian
      - fix RoCE setting at HCA level if not supported at all
      - don't turn CQE compression on by default for IPoIB

   - eth: ena:
      - fix toeplitz initial hash key value
      - account for the number of XDP-processed bytes in interface stats
      - fix rx_copybreak value update

  Misc:

   - ethtool: harden phy stat handling against buggy drivers

   - docs: netdev: convert maintainer's doc from FAQ to a normal
     document"

* tag 'net-6.2-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (112 commits)
  caif: fix memory leak in cfctrl_linkup_request()
  inet: control sockets should not use current thread task_frag
  net/ulp: prevent ULP without clone op from entering the LISTEN status
  qed: allow sleep in qed_mcp_trace_dump()
  MAINTAINERS: Update maintainers for ptp_vmw driver
  usb: rndis_host: Secure rndis_query check against int overflow
  net: dpaa: Fix dtsec check for PCS availability
  octeontx2-pf: Fix lmtst ID used in aura free
  drivers/net/bonding/bond_3ad: return when there's no aggregator
  netfilter: ipset: Rework long task execution when adding/deleting entries
  netfilter: ipset: fix hash:net,port,net hang with /0 subnet
  net: sparx5: Fix reading of the MAC address
  vxlan: Fix memory leaks in error path
  net: sched: htb: fix htb_classify() kernel-doc
  net: sched: cbq: dont intepret cls results when asked to drop
  net: sched: atm: dont intepret cls results when asked to drop
  dt-bindings: net: marvell,orion-mdio: Fix examples
  dt-bindings: net: sun8i-emac: Add phy-supply property
  net: ipa: use proper endpoint mask for suspend
  selftests: net: return non-zero for failures reported in arp_ndisc_evict_nocarrier
  ...

netfilter: ipset: Rework long task execution when adding/deleting entries

2023-01-02T14:10:05+00:00

When adding/deleting large number of elements in one step in ipset, it can
take a reasonable amount of time and can result in soft lockup errors. The
patch 5f7b51bf09ba ("netfilter: ipset: Limit the maximal range of
consecutive elements to add/delete") tried to fix it by limiting the max
elements to process at all. However it was not enough, it is still possible
that we get hung tasks. Lowering the limit is not reasonable, so the
approach in this patch is as follows: rely on the method used at resizing
sets and save the state when we reach a smaller internal batch limit,
unlock/lock and proceed from the saved state. Thus we can avoid long
continuous tasks and at the same time removed the limit to add/delete large
number of elements in one step.

The nfnl mutex is held during the whole operation which prevents one to
issue other ipset commands in parallel.

Fixes: 5f7b51bf09ba ("netfilter: ipset: Limit the maximal range of consecutive elements to add/delete")
Reported-by: syzbot+9204e7399656300bf271@syzkaller.appspotmail.com
Signed-off-by: Jozsef Kadlecsik 
Signed-off-by: Pablo Neira Ayuso

netfilter: ipset: fix hash:net,port,net hang with /0 subnet

2023-01-02T14:09:02+00:00

The hash:net,port,net set type supports /0 subnets. However, the patch
commit 5f7b51bf09baca8e titled "netfilter: ipset: Limit the maximal range
of consecutive elements to add/delete" did not take into account it and
resulted in an endless loop. The bug is actually older but the patch
5f7b51bf09baca8e brings it out earlier.

Handle /0 subnets properly in hash:net,port,net set types.

Fixes: 5f7b51bf09ba ("netfilter: ipset: Limit the maximal range of consecutive elements to add/delete")
Reported-by: Марк Коренберг 
Signed-off-by: Jozsef Kadlecsik 
Signed-off-by: Pablo Neira Ayuso

treewide: Convert del_timer() to timer_shutdown()

2022-12-25T21:38:09+00:00

Due to several bugs caused by timers being re-armed after they are
shutdown and just before they are freed, a new state of timers was added
called "shutdown".  After a timer is set to this state, then it can no
longer be re-armed.

The following script was run to find all the trivial locations where
del_timer() or del_timer_sync() is called in the same function that the
object holding the timer is freed.  It also ignores any locations where
the timer->function is modified between the del_timer*() and the free(),
as that is not considered a "trivial" case.

This was created by using a coccinelle script and the following
commands:

    $ cat timer.cocci
    @@
    expression ptr, slab;
    identifier timer, rfield;
    @@
    (
    -       del_timer(&ptr->timer);
    +       timer_shutdown(&ptr->timer);
    |
    -       del_timer_sync(&ptr->timer);
    +       timer_shutdown_sync(&ptr->timer);
    )
      ... when strict
          when != ptr->timer
    (
            kfree_rcu(ptr, rfield);
    |
            kmem_cache_free(slab, ptr);
    |
            kfree(ptr);
    )

    $ spatch timer.cocci . > /tmp/t.patch
    $ patch -p1 < /tmp/t.patch

Link: https://lore.kernel.org/lkml/20221123201306.823305113@linutronix.de/
Signed-off-by: Steven Rostedt (Google) 
Acked-by: Pavel Machek  [ LED ]
Acked-by: Kalle Valo  [ wireless ]
Acked-by: Paolo Abeni  [ networking ]
Signed-off-by: Linus Torvalds

netfilter: nf_tables: honor set timeout and garbage collection updates

2022-12-22T09:36:37+00:00

Set timeout and garbage collection interval updates are ignored on
updates. Add transaction to update global set element timeout and
garbage collection interval.

Fixes: 96518518cc41 ("netfilter: add nftables")
Suggested-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: perform type checking for existing sets

2022-12-21T16:34:00+00:00

If a ruleset declares a set name that matches an existing set in the
kernel, then validate that this declaration really refers to the same
set, otherwise bail out with EEXIST.

Currently, the kernel reports success when adding a set that already
exists in the kernel. This usually results in EINVAL errors at a later
stage, when the user adds elements to the set, if the set declaration
mismatches the existing set representation in the kernel.

Add a new function to check that the set declaration really refers to
the same existing set in the kernel.

Fixes: 96518518cc41 ("netfilter: add nftables")
Reported-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: add function to create set stateful expressions