Pablo Neira Ayuso says:

====================
Netfilter for net

This is v3, I kept back an ipset fix and another to tigthen the xtables
interface to reject invalid combinations with the NFPROTO_ARP family.
They need a bit more discussion. I fixed the issues reported by AI on
patch 9 (add #ifdef to access ct zone, update nf_conntrack_broadcast
and patch 10 (use better Fixes: tag). Thanks!

The following patchset contains Netfilter fixes for *net*.

Note that most bugs fixed here stem from 2.6 days, the large PR is not
due to an increase in regressions.

1) Fix incorrect reject of set updates with nf_tables pipapo set
   avx2 backend.  This comes with a regression test in patch 2.
   From Florian Westphal.

2) nfnetlink_log needs to zero padding to prevent infoleak to userspace,
   from Weiming Shi.

3) xtables ip6t_rt module never validated that addrnr length is within the
   allowed array boundary. Reject bogus values.  From Ren Wei.

4) Fix high memory usage in rbtree set backend that was unwanted side-effect
   of the recently added binary search blob. From Pablo Neira Ayuso.

5) Patches 5 to 10, also from Pablo, address long-standing RCU safety bugs
   in conntracks handling of expectations: We can never safely defer
   a conntrack extension area without holding a reference. Yet expectation
   handling does so in multiple places.  Fix this by avoiding the need to
   look into the master conntrack to begin with and by extending locked
   sections in a few places.

11) Fix use of uninitialized rtp_addr in the sip conntrack helper,
    also from Weiming Shi.

12) Add stricter netlink policy checks in ctnetlink, from David Carlier.
    This avoids undefined behaviour when userspace provides huge wscale
    value.

netfilter pull request 26-03-26

* tag 'nf-26-03-26' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: ctnetlink: use netlink policy range checks
  netfilter: nf_conntrack_sip: fix use of uninitialized rtp_addr in process_sdp
  netfilter: nf_conntrack_expect: skip expectations in other netns via proc
  netfilter: nf_conntrack_expect: store netns and zone in expectation
  netfilter: ctnetlink: ensure safe access to master conntrack
  netfilter: nf_conntrack_expect: use expect->helper
  netfilter: nf_conntrack_expect: honor expectation helper field
  netfilter: nft_set_rbtree: revisit array resize logic
  netfilter: ip6t_rt: reject oversized addrnr in rt_mt6_check()
  netfilter: nfnetlink_log: fix uninitialized padding leak in NFULA_PAYLOAD
  selftests: netfilter: nft_concat_range.sh: add check for flush+reload bug
  netfilter: nft_set_pipapo_avx2: don't return non-matching entry on expiry
====================

Link: https://patch.msgid.link/20260326125153.685915-1-pablo@netfilter.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Luiz Augusto von Dentz says:

====================
bluetooth pull request for net:

 - L2CAP: Fix deadlock in l2cap_conn_del()
 - L2CAP: Fix ERTM re-init and zero pdu_len infinite loop
 - L2CAP: Fix send LE flow credits in ACL link
 - btintel: serialize btintel_hw_error() with hci_req_sync_lock
 - btusb: clamp SCO altsetting table indices

* tag 'for-net-2026-03-25' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth:
  Bluetooth: btusb: clamp SCO altsetting table indices
  Bluetooth: L2CAP: Fix ERTM re-init and zero pdu_len infinite loop
  Bluetooth: L2CAP: Fix deadlock in l2cap_conn_del()
  Bluetooth: btintel: serialize btintel_hw_error() with hci_req_sync_lock
  Bluetooth: L2CAP: Fix send LE flow credits in ACL link
====================

Link: https://patch.msgid.link/20260325194358.618892-1-luiz.dentz@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Replace manual range and mask validations with netlink policy
annotations in ctnetlink code paths, so that the netlink core rejects
invalid values early and can generate extack errors.

- CTA_PROTOINFO_TCP_STATE: reject values > TCP_CONNTRACK_SYN_SENT2 at
  policy level, removing the manual >= TCP_CONNTRACK_MAX check.
- CTA_PROTOINFO_TCP_WSCALE_ORIGINAL/REPLY: reject values > TCP_MAX_WSCALE
  (14). The normal TCP option parsing path already clamps to this value,
  but the ctnetlink path accepted 0-255, causing undefined behavior when
  used as a u32 shift count.
- CTA_FILTER_ORIG_FLAGS/REPLY_FLAGS: use NLA_POLICY_MASK with
  CTA_FILTER_F_ALL, removing the manual mask checks.
- CTA_EXPECT_FLAGS: use NLA_POLICY_MASK with NF_CT_EXPECT_MASK, adding
  a new mask define grouping all valid expect flags.

Extracted from a broader nf-next patch by Florian Westphal, scoped to
ctnetlink for the fixes tree.

Fixes: c8e2078cfe41 ("[NETFILTER]: ctnetlink: add support for internal tcp connection tracking flags handling")
Signed-off-by: David Carlier <devnexen@gmail.com>
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

process_sdp() declares union nf_inet_addr rtp_addr on the stack and
passes it to the nf_nat_sip sdp_session hook after walking the SDP
media descriptions. However rtp_addr is only initialized inside the
media loop when a recognized media type with a non-zero port is found.

If the SDP body contains no m= lines, only inactive media sections
(m=audio 0 ...) or only unrecognized media types, rtp_addr is never
assigned. Despite that, the function still calls hooks->sdp_session()
with &rtp_addr, causing nf_nat_sdp_session() to format the stale stack
value as an IP address and rewrite the SDP session owner and connection
lines with it.

With CONFIG_INIT_STACK_ALL_ZERO (default on most distributions) this
results in the session-level o= and c= addresses being rewritten to
0.0.0.0 for inactive SDP sessions. Without stack auto-init the
rewritten address is whatever happened to be on the stack.

Fix this by pre-initializing rtp_addr from the session-level connection
address (caddr) when available, and tracking via a have_rtp_addr flag
whether any valid address was established. Skip the sdp_session hook
entirely when no valid address exists.

Fixes: 4ab9e64e5e3c ("[NETFILTER]: nf_nat_sip: split up SDP mangling")
Reported-by: Xiang Mei <xmei5@asu.edu>
Signed-off-by: Weiming Shi <bestswngs@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Skip expectations that do not reside in this netns.

Similar to e77e6ff502ea ("netfilter: conntrack: do not dump other netns's
conntrack entries via proc").

Fixes: 9b03f38d0487 ("netfilter: netns nf_conntrack: per-netns expectations")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

__nf_ct_expect_find() and nf_ct_expect_find_get() are called under
rcu_read_lock() but they dereference the master conntrack via
exp->master.

Since the expectation does not hold a reference on the master conntrack,
this could be dying conntrack or different recycled conntrack than the
real master due to SLAB_TYPESAFE_RCU.

Store the netns, the master_tuple and the zone in struct
nf_conntrack_expect as a safety measure.

This patch is required by the follow up fix not to dump expectations
that do not belong to this netns.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Holding reference on the expectation is not sufficient, the master
conntrack object can just go away, making exp->master invalid.

To access exp->master safely:

- Grab the nf_conntrack_expect_lock, this gets serialized with
  clean_from_lists() which also holds this lock when the master
  conntrack goes away.

- Hold reference on master conntrack via nf_conntrack_find_get().
  Not so easy since the master tuple to look up for the master conntrack
  is not available in the existing problematic paths.

This patch goes for extending the nf_conntrack_expect_lock section
to address this issue for simplicity, in the cases that are described
below this is just slightly extending the lock section.

The add expectation command already holds a reference to the master
conntrack from ctnetlink_create_expect().

However, the delete expectation command needs to grab the spinlock
before looking up for the expectation. Expand the existing spinlock
section to address this to cover the expectation lookup. Note that,
the nf_ct_expect_iterate_net() calls already grabs the spinlock while
iterating over the expectation table, which is correct.

The get expectation command needs to grab the spinlock to ensure master
conntrack does not go away. This also expands the existing spinlock
section to cover the expectation lookup too. I needed to move the
netlink skb allocation out of the spinlock to keep it GFP_KERNEL.

For the expectation events, the IPEXP_DESTROY event is already delivered
under the spinlock, just move the delivery of IPEXP_NEW under the
spinlock too because the master conntrack event cache is reached through
exp->master.

While at it, add lockdep notations to help identify what codepaths need
to grab the spinlock.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Use expect->helper in ctnetlink and /proc to dump the helper name.
Using nfct_help() without holding a reference to the master conntrack
is unsafe.

Use exp->master->helper in ctnetlink path if userspace does not provide
an explicit helper when creating an expectation to retain the existing
behaviour. The ctnetlink expectation path holds the reference on the
master conntrack and nf_conntrack_expect lock and the nfnetlink glue
path refers to the master ct that is attached to the skb.

Reported-by: Hyunwoo Kim <imv4bel@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

The expectation helper field is mostly unused. As a result, the
netfilter codebase relies on accessing the helper through exp->master.

Always set on the expectation helper field so it can be used to reach
the helper.

nf_ct_expect_init() is called from packet path where the skb owns
the ct object, therefore accessing exp->master for the newly created
expectation is safe. This saves a lot of updates in all callsites
to pass the ct object as parameter to nf_ct_expect_init().

This is a preparation patches for follow up fixes.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Chris Arges reports high memory consumption with thousands of
containers, this patch revisits the array allocation logic.

For anonymous sets, start by 16 slots (which takes 256 bytes on x86_64).
Expand it by x2 until threshold of 512 slots is reached, over that
threshold, expand it by x1.5.

For non-anonymous set, start by 1024 slots in the array (which takes 16
Kbytes initially on x86_64). Expand it by x1.5.

Use set->ndeact to subtract deactivated elements when calculating the
number of the slots in the array, otherwise the array size array gets
increased artifically. Add special case shrink logic to deal with flush
set too.

The shrink logic is skipped by anonymous sets.

Use check_add_overflow() to calculate the new array size.

Add a WARN_ON_ONCE check to make sure elements fit into the new array
size.

Reported-by: Chris Arges <carges@cloudflare.com>
Fixes: 7e43e0a1141d ("netfilter: nft_set_rbtree: translate rbtree to array for binary search")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>