Commit Graph
84856 Commits
Author SHA1 Message Date
Pablo Neira Ayuso ac46f3f35b netfilter: nf_conntrack_helper: add refcounting from datapath
This patch adds a new ->ct_refcnt field to struct nf_conntrack_helper
which is bumped when the helper is used by the ct helper extension. Drop
this reference count when the conntrack entry is released. This is a
packet path refcount which ensures that struct nf_conntrack_helper
remains in place for tricky scenarios where a packet sits in nfqueue, or
elsewhere, with a conntrack that refers to this helper.

For simplicity, this leaves a single refcount for helper objects in
place, remove the existing refcount for control plane that ensures that
the helper does not go away if it is used by ruleset.

On helper removal, the help callback is set to NULL to disable it from
packet path and, after rcu grace period, existing expectations are
removed. Update ctnetlink to disable access to .to_nlattr and
.from_nlattr if the helper is going away.

Remove nf_queue_nf_hook_drop() since it has proven not to be effective
because packets with unconfirmed conntracks which are still flying to
sit in nfqueue.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-05 16:16:44 +02:00
Pablo Neira Ayuso fe97fd540a netfilter: nf_conntrack_pptp: move GRE specific cleanup to GRE tracker
Move the GRE specific cleanup to nf_conntrack_proto_gre.c to ensure that
the .destroy callback for the pptp helper is still reachable by existing
conntrack entries while pptp module is being removed.

This is a preparation patch, no functional changes are intended.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-05 16:16:44 +02:00
Pablo Neira Ayuso 6031487d4e netfilter: nf_conntrack_helper: dynamically allocate struct nf_conntrack_helper
Adapt all existing helpers to use a modified version of
nf_ct_helper_init(), to dynamically allocate struct nf_conntrack_helper.

Allocate expect_policy[] built-in into the helper to ensure this area is
reachable after helper removal since a follow up patch adds refcount to
track use of the nf_conntrack_helper structure from packet path so it
remains around until last reference from ct helper extension is dropped.

Export __nf_conntrack_helper_register() which allows to register
nfnetlink_cthelper dynamically allocated helper. Adapt nfnetlink_cthelper
to use the built-in expect_policy[].

This is a preparation patch to add packet path refcounting to helpers.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-05 13:25:18 +02:00
Pablo Neira Ayuso 7d6a9cdb8d netfilter: cttimeout: detach dataplane timeout policy and repurpose refcount
Add a refcount for struct nf_ct_timeout which is used by ct extension to
set the custom ct timeout policy, this tells us that the ct timeout is
being used by a conntrack entry. When the last conntrack entry drops the
refcount on the ct timeout, the ct timeout is released.

Remove the refcount for control plane which controls if the ruleset
refers to the timeout policy. After this update, it is possible to
remove the ct timeout policy from nfnetlink_cttimeout immediately.
This is for simplicity not to handle two refcounts on a single object.

Remove nf_queue_nf_hook_drop(): a packet sitting in nfqueue will just
hold a reference to the nf_ct_timeout object until packet is reinjected,
since this is part of the ct extension, this will be released by the
time the conntrack is freed.

nf_ct_untimeout() is still called to clean up in a best effort basis:
the ct timeout on existing entries gets removed when the ct timeout goes
away, but as long as the iptables ruleset still refers to the ct timeout
through a template, new conntracks may keep attaching it and extend its
lifetime until the rule is removed.

nf_ct_untimeout() is not called anymore from module removal path, this
is unlikely to find timeouts give module refcount is bumped, and the new
refcount already tracks the ct timeout policy use so it is released when
unused.

Fixes: 5097846230 ("netfilter: add cttimeout infrastructure for fine timeout tuning")
Fixes: 7e0b2b57f0 ("netfilter: nft_ct: add ct timeout support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-05 13:11:55 +02:00
Fernando Fernandez Mancera 9e37388b80 netfilter: synproxy: protect nf_ct_seqadj_init() with conntrack lock
nf_ct_seqadj_init() is called without holding the ct lock. This can race
with nf_ct_seq_adjust() when a connection is in CLOSE state due to an
RST or connection reopening. In addition for SYN_RECV state, concurrent
processing of packets can trigger nf_ct_seq_adjust() too. These
situations create a read/write data race.

As synproxy is the only user of nf_ct_seqadj_init() at the moment, fix
this by holding ct->lock inside nf_ct_seqadj_init() until all is done.

Fixes: 48b1de4c11 ("netfilter: add SYNPROXY core/target")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-05 13:11:55 +02:00
Fernando Fernandez Mancera 992c20bc8a netfilter: synproxy: fix unaligned memory access in timestamp adjustment
Use get_unaligned_be32() and put_unaligned_be32() to safely read and
write the timestamp fields. This prevents performance degradation due to
unaligned memory access or even a crash on strict alignment
architectures.

This follows the implementation of timestamp parsing in the networking
stack at tcp_parse_options() and synproxy_parse_options().

Fixes: 48b1de4c11 ("netfilter: add SYNPROXY core/target")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-05 13:11:55 +02:00
Fernando Fernandez Mancera 22bb132cfb netfilter: synproxy: adjust duplicate timestamp options
RFC 9293 does not mention anything about duplicated options and each
networking stack handles it in their own way. Currently, Linux kernel is
processing options sequentially and in case of duplicated timestamp
options, the value from the latest one overrides the others.

As SYNPROXY is modifying only the first timestamp option found, a packet
can reach the backend server and it might parse the wrong timestamp
value. Let's just continue parsing the following options and in case a
duplicated timestamp is found, adjust it too.

Fixes: 48b1de4c11 ("netfilter: add SYNPROXY core/target")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-05 13:11:55 +02:00
Fernando Fernandez Mancera 63d29ee95c netfilter: synproxy: drop packets if timestamp adjustment fails
If a packet was malformed or if skb_ensure_writable() failed, the
synproxy_tstamp_adjust() function returned 0 indicating an error but it
was ignored on the callers.

Make the function return a boolean instead to clarify the result and
drop the packet if synproxy_tstamp_adjust() failed due to ENOMEM from
skb_ensure_writable(). In addition, if there are malformed options, skip
the tstamp update but do not drop the packet as that should be done by
the policy directly.

Fixes: 48b1de4c11 ("netfilter: add SYNPROXY core/target")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-05 13:11:54 +02:00
Pablo Neira Ayuso f8bf5edf71 netfilter: nfnetlink_cthelper: use {READ,WRITE}_ONCE for accessing helper flags
Conntrack helper flags are accessed from packet and netlink dump path.
Concurrent update of userspace helper flags is not possible, because the
nfnl_mutex in held on updates. These flags are only used by userspace
helpers. Use {READ,WRITE}_ONCE() to access this flags from lockless
paths.

Fixes: 12f7a50533 ("netfilter: add user-space connection tracking helper infrastructure")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-05 13:11:54 +02:00
Fernando Fernandez Mancera a625c94144 netfilter: nfnetlink_osf: fix mss parsing on big-endian architectures
The MSS calculation in nf_osf_match_one() manually shifts bytes to
construct a 16-bit value before passing it to ntohs().

This works on little-endian hosts but it does not work on big-endian as
the bytes are being always shifted and set in the same way for all
architectures.

Use get_unaligned_be16() to fix this on big-endian systems. It also
simplifies the code.

Fixes: 11eeef41d5 ("netfilter: passive OS fingerprint xtables match")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-05 13:11:54 +02:00
Julian Anastasov 4a15044a2b ipvs: add conn_max sysctl to limit connections
Currently, we are using atomic_t to track the number of
connections. On 64-bit setups with large memory there is
a risk this counter to overflow. Also, setups with many
containers may need to tune the limit for connections.

Add sysctl control to limit the number of connections to
1,073,741,824 (64-bit) and 16,777,216 (32-bit).
Depending on the admin's privilege, the value is
used to change a soft or hard limit allowing
unprivileged admins to change the soft limit in
range determined by privileged admins.

Link: https://sashiko.dev/#/patchset/20260523172715.94795-1-ja%40ssi.bg
Link: https://sashiko.dev/#/patchset/20260430074420.26697-7-ja%40ssi.bg
Link: https://sashiko.dev/#/patchset/20260522105546.13732-1-ja%40ssi.bg
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-05 13:11:54 +02:00
Jakub Kicinski bfa3d89cc1 Merge tag 'batadv-next-pullrequest-20260603' of https://git.open-mesh.org/batadv
Simon Wunderlich says:

====================
This cleanup patchset includes the following patches, all by
Sven Eckelmann:

- tp_meter: fix various minor issues (8 patches)

- tp_meter: split generic session type in sender and receiver type

- tp_meter: consolidate locking for congestion control (2 patches)

- bla: annotate lasttime access with READ/WRITE_ONCE

- elp: prevent transmission interval underflow

- tt: sync local and global tvlv preparation return values

- tt: directly retrieve wifi flags of net_device

* tag 'batadv-next-pullrequest-20260603' of https://git.open-mesh.org/batadv:
  batman-adv: tt: directly retrieve wifi flags of net_device
  batman-adv: tt: sync local and global tvlv preparation return values
  batman-adv: prevent ELP transmission interval underflow
  batman-adv: bla: annotate lasttime access with READ/WRITE_ONCE
  batman-adv: tp_meter: consolidate congestion control variables
  batman-adv: tp_meter: use locking for all congestion control variables
  batman-adv: tp_meter: split vars into sender and receiver types
  batman-adv: tp_meter: add only finished tp_vars to lists
  batman-adv: tp_meter: handle seqno wrap-around for fast recovery detection
  batman-adv: tp_meter: fix fast recovery precondition
  batman-adv: tp_meter: avoid divide-by-zero for dec_cwnd
  batman-adv: tp_meter: avoid window underflow
  batman-adv: tp_meter: initialize dec_cwnd explicitly
  batman-adv: tp_meter: initialize dup_acks explicitly
  batman-adv: tp_meter: keep unacked list in ascending ordered
====================

Link: https://patch.msgid.link/20260603072527.174487-1-sw@simonwunderlich.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 19:14:35 -07:00
Thorsten Blum 6ce66868d1 net/dns_resolver: use kasprintf + kmemdup_nul to simplify dns_query
Use kasprintf() for descriptions with a query type and kmemdup_nul()
otherwise to simplify dns_query().

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260602071343.962830-2-thorsten.blum@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 18:39:29 -07:00
Runyu Xiao f425c55cb6 ipv6: use READ_ONCE() in ipv6_flowlabel_get()
ipv6_flowlabel_get() reads flowlabel_consistency and
flowlabel_state_ranges locklessly.

Use READ_ONCE() for these sysctl accesses.

Signed-off-by: Runyu Xiao <runyu.xiao@seu.edu.cn>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260602002506.1519901-1-runyu.xiao@seu.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 18:31:18 -07:00
Runyu Xiao 7a20eb5422 ipv6: use READ_ONCE() for bindv6only default in inet6_create()
inet6_create() reads net->ipv6.sysctl.bindv6only locklessly.

Use READ_ONCE() for this sysctl access.

Signed-off-by: Runyu Xiao <runyu.xiao@seu.edu.cn>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260602002414.1504106-1-runyu.xiao@seu.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 18:30:24 -07:00
yuan.gao 831d557a3e inet: frags: remove redundant assignment in inet_frag_reasm_prepare()
The assignment is redundant because skb_clone() already copies skb->cb.

Remove the unnecessary code.

Signed-off-by: yuan.gao <yuan.gao@ucloud.cn>
Link: https://patch.msgid.link/20260603065323.2736839-1-yuan.gao@ucloud.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 18:26:11 -07:00
Eric Dumazet f3c4961054 rtnetlink: use dev_isalive() in rtnl_getlink()
rtnl_getlink() uses an RCU lookup to get the netdevice pointer.

When/If rtnl_lock() is used, we should check if the netdevice is not
being dismantled before potentially perform illegal actions.

Move dev_isalive() out of net/core/net-sysfs.c and make it available
in net/core/dev.h.

Return -ENODEV if rtnl_getlink() finds a device which is currently
being dismantled and RTNL is requested.

Fixes: e896e5c073 ("rtnetlink: do not acquire RTNL in rtnl_getlink() with RTEXT_FILTER_NAME_ONLY")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Link: https://patch.msgid.link/20260603180831.1024716-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 18:16:14 -07:00
Ido Schimmel 7a188fcc18 bridge: mcast: Synchronously shutdown port multicast timers
Currently, while four timers are set up during port multicast context
initialization, only two are synchronously deleted when the context is
de-initialized, just before being deleted.

This is fine because the structure containing the multicast context
(either a bridge port or a VLAN) is only deleted after an RCU grace
period and it will not pass as long as the timers are executing. These
timers are also not supposed to do any work at this stage. They acquire
the bridge multicast lock, see that the multicast context was disabled
and exit.

Make the code more explicit and symmetric and synchronously shutdown all
four timers when the multicast context is de-initialized. Use
timer_shutdown_sync() to guarantee that the timers will not be re-armed
given that the containing structure is being deleted.

Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260603103522.622411-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 18:11:54 -07:00
Jakub Kicinski 8d72997dab Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-7.1-rc7).

Silent conflicts:

net/wireless/nl80211.c
  cb9959ab5f ("wifi: cfg80211: enforce HE/EHT cap/oper consistency")
  a384ae9699 ("wifi: cfg80211: move AP HT/VHT/... operation to beacon info")
https://lore.kernel.org/aiGJDaHV4UlCexIQ@sirena.org.uk

Conflicts:

drivers/net/wireless/intel/iwlwifi/mld/ap.c
  a342c99cb7 ("wifi: iwlwifi: mld: honor BSS_CHANGED_BEACON_ENABLED")
  9bf1b409af ("wifi: iwlwifi: mld: send tx power constraints before link activation")
https://lore.kernel.org/ah2bfedhV45ZxMO8@sirena.org.uk

drivers/net/wireless/intel/iwlwifi/pcie/drv.c
  093305d801 ("wifi: iwlwifi: pcie: simplify the resume flow if fast resume is not used")
  e2323929a6 ("wifi: iwlwifi: pcie: add debug print for resume flow if powered off")
https://lore.kernel.org/ah2bfedhV45ZxMO8@sirena.org.uk

Adjacent changes:

drivers/net/ethernet/airoha/airoha_eth.c
  b38cae85d1 ("net: airoha: Fix use-after-free in metadata dst teardown")
  ec6c391bcc ("net: airoha: Introduce airoha_gdm_dev struct")

drivers/net/ethernet/microchip/lan743x_main.c
  8173d22b21 ("net: lan743x: permit VLAN-tagged packets up to configured MTU")
  e3c6508a46 ("net: lan743x: avoid netdev-based logging before netdev registration")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 15:29:04 -07:00
Jakub Kicinski 9f275c2e90 net: ethtool: make sure __ethtool_get_link_ksettings() is ops-locked
All drivers which may call *_get_link_ksettings() on ops-locked
devices from paths already holding the ops lock are ready now.
Make __ethtool_get_link_ksettings() take the ops lock, and assert
that it's held in netif_get_link_ksettings().

Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260603012840.2254293-12-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 14:04:56 -07:00
Jakub Kicinski e50f6245be net: sched: don't recurse on the netdev ops lock in qdiscs
cbs_set_port_rate() and taprio_set_picos_per_byte() are reached from
two paths and both already hold the device's ops lock:

 *_change(), via tc_modify_qdisc() which calls netdev_lock_ops(dev)
    before dispatching to the qdisc ops.

 *_dev_notifier() on NETDEV_UP / NETDEV_CHANGE, where caller
    holds the ops lock across the notifier chain.

Switch to netif_get_link_ksettings() to avoid deadlock once
__ethtool_get_link_ksettings() starts taking the netdev lock.

Link: https://patch.msgid.link/20260603012840.2254293-9-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 14:04:56 -07:00
Jakub Kicinski 20398c41d0 net: bridge: don't recurse on the port's netdev ops lock
port_cost() calls __ethtool_get_link_ksettings() on the port device,
which will soon take the port's ops lock. br_port_carrier_check()
is reached via the NETDEV_CHANGE notifier from linkwatch, which
already holds the port's ops lock, so the call would deadlock.

Make port_cost() expect the port's ops lock held and switch to
netif_get_link_ksettings(). The only other caller is new_nbp(),
make sure it takes the lock explicitly.

Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260603012840.2254293-8-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 14:04:56 -07:00
Jakub Kicinski f32fe1d79a net: ethtool: add netif_get_link_ksettings() for correct ops-locked use
__ethtool_get_link_ksettings() is exported and called from sysfs
and many drivers. It invokes ethtool_ops->get_link_ksettings
so by our own docs it should be holding netdev lock for ops locked
devices. Looks like commit 2bcf4772e4 ("net: ethtool:
try to protect all callback with netdev instance lock")
missed adding the ops lock here.

There's a number of callers we need to fix up so let's add the
netif_get_link_ksettings() helper first, without any actual
locking changes (this commit is a nop).

Not treating this as a fix because I don't think any driver cares
at this point, but if we want to remove the rtnl_lock protection
this will become critical.

Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260603012840.2254293-5-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 14:04:55 -07:00
Jakub Kicinski b8dfa196cb net: document NETDEV_CHANGENAME as ops locked
NETDEV_CHANGENAME is only emitted from netif_change_name().
netif_change_name() has two callers both of which hold netdev_lock_ops()
around the call site:
 - dev_change_name()
 - do_setlink()

Document NETDEV_CHANGENAME as always ops locked.

Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260603012840.2254293-4-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 14:04:55 -07:00
Jakub Kicinski 1d3964e29e net: ethtool: cmis_cdb: hold instance lock for ops locked devices
FW module flashing was written so that the flashing happens
without holding rtnl_lock. This allows flashing multiple modules
at once. Current drivers can handle that well, but we should
let drivers depend on the netdev instance lock. Instance lock
is per netdev, and so is the module so we won't break parallel
updates.

Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260603012840.2254293-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 14:04:55 -07:00
Jakub Kicinski 251bc9db88 net: rename netdev_ops_assert_locked()
Jakub suggests renaming the existing assert to match
the netdev_lock_ops_compat() semantics.

We want netdev_assert_locked_ops() to mean - if the driver
is ops locked - check that it's holding the device lock.

The existing helper check for either ops lock or rtnl_lock,
which is the locking behavior of netdev_lock_ops_compat().

The reason for naming divergence is likely that
netdev_ops_assert_locked() predated the _compat() helpers.

Suggested-by: Jakub Sitnicki <jakub@cloudflare.com>
Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260603012840.2254293-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 14:04:55 -07:00
Sechang Lim 3c94f241f7 udp: clear skb->dev before running a sockmap verdict
On the UDP receive path skb->dev is repurposed as dev_scratch (the
truesize/state cache set by udp_set_dev_scratch()), through the
union { struct net_device *dev; unsigned long dev_scratch; } in sk_buff.

When a UDP socket is in a sockmap, sk_data_ready is
sk_psock_verdict_data_ready(), which calls udp_read_skb() -> recv_actor()
(sk_psock_verdict_recv) to run the attached SK_SKB verdict program in softirq.
If that program calls a socket-lookup helper (bpf_sk_lookup_tcp/udp,
bpf_skc_lookup_tcp), bpf_skc_lookup() does:

	if (skb->dev)
		caller_net = dev_net(skb->dev);

skb->dev still holds the dev_scratch value (a non-NULL integer), so dev_net()
dereferences it as a struct net_device * and the kernel takes a general
protection fault on a non-canonical address in softirq:

  Oops: general protection fault, probably for non-canonical address 0x1010000800004a0
  CPU: 1 UID: 0 PID: 1406 Comm: syz.2.19 Not tainted 7.1.0-rc6 #1 PREEMPT(full)
  RIP: 0010:bpf_skc_lookup net/core/filter.c:7033 [inline]
  RIP: 0010:bpf_sk_lookup+0x45/0x160 net/core/filter.c:7047
  Call Trace:
   <IRQ>
   bpf_prog_4675cb904b7071f8+0x12e/0x14e
   bpf_prog_run_pin_on_cpu+0xc6/0x1f0
   sk_psock_verdict_recv+0x1ba/0x350
   udp_read_skb+0x31a/0x370
   sk_psock_verdict_data_ready+0x2e3/0x600
   __udp_enqueue_schedule_skb+0x4c8/0x650
   udpv6_queue_rcv_one_skb+0x3ec/0x740
   udp6_unicast_rcv_skb+0x11d/0x140
   ip6_protocol_deliver_rcu+0x61e/0x950
   ip6_input_finish+0xa9/0x150
   NF_HOOK+0x286/0x2f0
   ip6_input+0x117/0x220
   NF_HOOK+0x286/0x2f0
   __netif_receive_skb+0x85/0x200
   process_backlog+0x374/0x9a0
   __napi_poll+0x4f/0x1c0
   net_rx_action+0x3b0/0x770
   handle_softirqs+0x15a/0x460
   do_softirq+0x57/0x80
   </IRQ>

The rmem charge that dev_scratch accounted for is released by skb_recv_udp() on
dequeue, just above, so the scratch is dead by the time recv_actor() runs. Clear
skb->dev so bpf_skc_lookup() falls back to sock_net(skb->sk), which
skb_set_owner_sk_safe() set just above.

Fixes: 965b57b469 ("net: Introduce a new proto_ops ->read_skb()")
Cc: stable@vger.kernel.org
Signed-off-by: Sechang Lim <rhkrqnwk98@gmail.com>
Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260603162737.697215-1-rhkrqnwk98@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 09:01:51 -07:00
Xin Long e374b22e9b sctp: purge outqueue on stale COOKIE-ECHO handling
sctp_stream_update() is only invoked when the association is moved into
COOKIE_WAIT during association setup/reconfiguration. In this path, the
outbound stream scheduler state (stream->out_curr) is expected to be
clean, since no user data should have been transmitted yet unless the
state machine has already partially progressed.

However, a corner case exists in sctp_sf_do_5_2_6_stale(): when a
Stale Cookie ERROR is received, the association is rolled back from
COOKIE_ECHOED to COOKIE_WAIT. In this scenario, user data may already
have been queued and even bundled with the COOKIE-ECHO chunk.

During the rollback, sctp_stream_update() frees the old stream table
and installs a new one, but it does not invalidate stream->out_curr.
As a result, out_curr may still point to a freed sctp_stream_out
entry from the previous stream state.

Later, SCTP scheduler dequeue paths (FCFS, RR, PRIO, etc.) rely on
stream->out_curr->ext, which can lead to use-after-free once the old
stream state has been released via sctp_stream_free().

This results in crashes such as (reported by Yuqi):

  BUG: KASAN: slab-use-after-free in sctp_sched_fcfs_dequeue+0x13a/0x140
  Read of size 8 at addr ff1100004d4d3208 by task mini_poc/9312
  CPU: 1 UID: 1001 PID: 9312 Comm: mini_poc Not tainted
     7.1.0-rc1-00305-gbd3a4795d574 #5 PREEMPT(full)
   sctp_sched_fcfs_dequeue+0x13a/0x140
   sctp_outq_flush+0x1603/0x33e0
   sctp_do_sm+0x31c9/0x5d30
   sctp_assoc_bh_rcv+0x392/0x6f0
   sctp_inq_push+0x1db/0x270
   sctp_rcv+0x138d/0x3c10

Fix this by fully purging the association outqueue when handling the
Stale Cookie case. This ensures all pending transmit and retransmit
state is dropped, and any scheduler cached pointers are invalidated,
making it safe to rebuild stream state during COOKIE_WAIT restart.

Updating only stream->out_curr would be insufficient, since queued
and retransmittable data would still reference the old stream state and
trigger later use-after-free in dequeue paths.

Fixes: 5bbbbe32a4 ("sctp: introduce stream scheduler foundations")
Reported-by: Yuan Tan <yuantan098@gmail.com>
Reported-by: Yifan Wu <yifanwucs@gmail.com>
Reported-by: Juefei Pu <tomapufckgml@gmail.com>
Reported-by: Zhengchuan Liang <zcliangcn@gmail.com>
Reported-by: Xin Liu <bird@lzu.edu.cn>
Reported-by: Yuqi Xu <xuyq21@lenovo.com>
Reported-by: Ren Wei <n05ec@lzu.edu.cn>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/94318159b9052907a6cbb7256aee8b5f8dfbfccb.1780510304.git.lucien.xin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 09:01:25 -07:00
Yizhou Zhao 7561c7fbc6 net/802/mrp: fix vector attribute parsing in mrp_pdu_parse_vecattr
In mrp_pdu_parse_vecattr(), vector attribute events are encoded three
per byte and valen tracks the number of events left to process.

The parser decrements valen after processing the first and second events
from each event byte, but not after processing the third one. When valen
is exactly a multiple of three, the loop continues after the last valid
event and consumes the next byte as a new event byte, applying a
spurious event to the MRP applicant state.

Additionally, when valen is zero the parser unconditionally consumes
attrlen bytes as FirstValue and advances the offset, even though per
IEEE 802.1ak a VectorAttribute with only a LeaveAllEvent has valen of
zero and no FirstValue or Vector fields. This corrupts the offset for
subsequent PDU parsing.

Also, when valen exceeds three the loop crosses byte boundaries but
the attribute value is not incremented between the last event of one
byte and the first event of the next. This causes the first event of
the next byte to use the same attribute value as the third event
rather than the next consecutive value.

Decrement valen after processing the third event, skip FirstValue
consumption when valen is zero, and increment the attribute value at
the end of each loop iteration.

Fixes: febf018d22 ("net/802: Implement Multiple Registration Protocol (MRP)")
Reported-by: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn>
Reported-by: Yuxiang Yang <yangyx22@mails.tsinghua.edu.cn>
Reported-by: Ao Wang <wangao@seu.edu.cn>
Reported-by: Xuewei Feng <fengxw06@126.com>
Reported-by: Qi Li <qli01@tsinghua.edu.cn>
Reported-by: Ke Xu <xuke@tsinghua.edu.cn>
Signed-off-by: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn>
Link: https://patch.msgid.link/20260603060016.21522-1-zhaoyz24@mails.tsinghua.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 08:52:41 -07:00
Eric Dumazet 3a5f3f7aff ieee802154: 6lowpan: only accept IPv6 packets in lowpan_xmit()
The aoe driver (or similar) generates a non-IPv6 packet
(e.g., ETH_P_AOE) and queues it for transmission via dev_queue_xmit()
on a 6LoWPAN interface (configured by the user or test case).

Since the packet is not IPv6, the 6LoWPAN header_ops->create function
(lowpan_header_create or header_create) returns early without initializing
the lowpan_addr_info structure in the skb headroom.

In the transmit function (lowpan_xmit), the driver calls lowpan_header
(or setup_header) which unconditionally copies and uses the lowpan_addr_info
from the headroom, which contains uninitialized data.

Fix this by dropping non IPv6 packets.

A similar fix is needed in net/bluetooth/6lowpan.c bt_xmit().

Fixes: 4dc315e267 ("ieee802154: 6lowpan: move transmit functionality")
Reported-by: syzbot+f13c19f75e1097abd116@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/6a1fd763.278b5b03.2bcf39.0049.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://patch.msgid.link/20260603072955.4032221-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 08:51:32 -07:00
Ido Schimmel 791c91dc7a ipv6: mcast: Fix use-after-free when processing MLD queries
When processing an MLD query, a pointer to the multicast group address
is retrieved when initially parsing the packet. This pointer is later
dereferenced without being reloaded despite the fact that the skb header
might have been reallocated following the pskb_may_pull() calls, leading
to a use-after-free [1].

Fix by copying the multicast group address when the packet is initially
parsed.

[1]
BUG: KASAN: slab-use-after-free in __mld_query_work (net/ipv6/mcast.c:1512)
Read of size 8 at addr ffff8881154b8e90 by task kworker/4:1/118

Workqueue: mld mld_query_work
Call Trace:
<TASK>
dump_stack_lvl (lib/dump_stack.c:94 lib/dump_stack.c:120)
print_address_description.constprop.0 (mm/kasan/report.c:378)
print_report (mm/kasan/report.c:482)
kasan_report (mm/kasan/report.c:595)
__mld_query_work (net/ipv6/mcast.c:1512)
mld_query_work (net/ipv6/mcast.c:1563)
process_one_work (kernel/workqueue.c:3314)
worker_thread (kernel/workqueue.c:3397 kernel/workqueue.c:3478)
kthread (kernel/kthread.c:436)
ret_from_fork (arch/x86/kernel/process.c:158)
ret_from_fork_asm (arch/x86/entry/entry_64.S:245)
</TASK>

[...]

Freed by task 118:
kasan_save_stack (mm/kasan/common.c:57)
kasan_save_track (mm/kasan/common.c:78)
kasan_save_free_info (mm/kasan/generic.c:584)
__kasan_slab_free (mm/kasan/common.c:253 mm/kasan/common.c:285)
kfree (./include/linux/kasan.h:235 mm/slub.c:2689 mm/slub.c:6251 mm/slub.c:6566)
pskb_expand_head (net/core/skbuff.c:2335)
__pskb_pull_tail (net/core/skbuff.c:2878 (discriminator 4))
__mld_query_work (net/ipv6/mcast.c:1495 (discriminator 1))
mld_query_work (net/ipv6/mcast.c:1563)
process_one_work (kernel/workqueue.c:3314)
worker_thread (kernel/workqueue.c:3397 kernel/workqueue.c:3478)
kthread (kernel/kthread.c:436)
ret_from_fork (arch/x86/kernel/process.c:158)
ret_from_fork_asm (arch/x86/entry/entry_64.S:245)

Fixes: 97300b5fdf ("[MCAST] IPv6: Check packet size when process Multicast")
Reported-by: Leo Lin <leo@depthfirst.com>
Reviewed-by: David Ahern <dahern@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Link: https://patch.msgid.link/20260603101811.612594-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 08:50:33 -07:00
Xin Long 0861615c28 sctp: validate cached peer INIT chunk length in COOKIE_ECHO processing
When a listening SCTP server processes a COOKIE_ECHO chunk, the cached
peer INIT chunk embedded after the cookie is parsed and its parameters
are later walked by sctp_process_init() using sctp_walk_params().

However, the chunk header length of this cached INIT chunk was not
validated against the remaining buffer in the COOKIE_ECHO payload. If
the length field is inflated, the parameter walk can run beyond the
actual received data, leading to out-of-bounds reads and potential
memory corruption during later parameter handling (e.g. STATE_COOKIE
processing and kmemdup() copies).

Add a bounds check in sctp_unpack_cookie() to ensure the cached INIT
chunk length does not exceed the available data in the COOKIE_ECHO
buffer before it is used.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: Brian Geffon <bgeffon@google.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/eb60825fa22d6f9e663c7d4dbb69f397b5d34d42.1780362366.git.lucien.xin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 08:30:07 -07:00
Rajat Gupta 899ee91156 net/sched: fix pedit partial COW leading to page cache corruption
tcf_pedit_act() computes the COW range for skb_ensure_writable()
once before the key loop using tcfp_off_max_hint, but the hint does
not account for the runtime header offset added by typed keys. This
can leave part of the write region un-COW'd.

Fix by moving skb_ensure_writable() inside the per-key loop where
the actual write offset is known, and add overflow checking on the
offset arithmetic. For negative offsets (e.g. Ethernet header edits
at ingress), use skb_cow() to COW the headroom instead. Guard
offset_valid() against INT_MIN, where negation is undefined.

Fixes: 8b796475fd ("net/sched: act_pedit: really ensure the skb is writable")
Reported-by: Yiming Qian <yimingqian591@gmail.com>
Reported-by: Keenan Dong <keenanat2000@gmail.com>
Reported-by: Han Guidong <2045gemini@gmail.com>
Reported-by: Zhang Cen <rollkingzzc@gmail.com>
Reviewed-by: Han Guidong <2045gemini@gmail.com>
Tested-by: Han Guidong <2045gemini@gmail.com>
Reviewed-by: Davide Caratti <dcaratti@redhat.com>
Tested-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Tested-by: Toke Høiland-Jørgensen <toke@redhat.com>
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Tested-by: Victor Nogueira <victor@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Rajat Gupta <rajat.gupta@oss.qualcomm.com>
Link: https://patch.msgid.link/20260531123221.48732-1-jhs@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 08:29:02 -07:00
Raf Dickson c05fa14db4 vsock/vmci: fix sk_ack_backlog leak on failed handshake
When vmci_transport_recv_connecting_server() returns an error,
vmci_transport_recv_listen() calls vsock_remove_pending() but never
calls sk_acceptq_removed(). This leaves sk_ack_backlog incremented
permanently.

Repeated handshake failures (malformed packets, queue pair alloc
failure, event subscribe failure) cause sk_ack_backlog to climb
toward sk_max_ack_backlog. Once it reaches the limit the listener
permanently refuses all new connections with -ECONNREFUSED, a
silent denial of service requiring a process restart to recover.

The two existing sk_acceptq_removed() calls in af_vsock.c do not
cover this path: line 764 checks vsock_is_pending() which returns
false after vsock_remove_pending(), and line 1889 is only reached
on successful accept().

Fix by balancing sk_acceptq_added() with sk_acceptq_removed() on
the error path.

Fixes: d021c34405 ("VSOCK: Introduce VM Sockets")
Cc: stable@vger.kernel.org
Signed-off-by: Raf Dickson <rafdog35@gmail.com>
Acked-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://patch.msgid.link/20260526104356.469928-1-rafdog35@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-06-04 13:08:02 +02:00
Justin Iurman ee5aee77bc ipv6: exthdrs: recompute network header pointer once
In ip6_parse_tlv(), recompute the network header pointer once regardless
of the option processed (Hbh or Dest), as missing recomputation for
specific options has caused issues in the past.

Signed-off-by: Justin Iurman <justin.iurman@gmail.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260602213033.12244-1-justin.iurman@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-03 19:14:56 -07:00
Jakub Kicinski d20da91308 Merge tag 'for-net-2026-06-03' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth
Luiz Augusto von Dentz says:

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

 - hci_core: fix memory leak in error path of hci_alloc_dev()
 - hci_sync: reject oversized Broadcast Announcement prepend
 - MGMT: Fix backward compatibility with userspace
 - MGMT: validate advertising TLV before type checks
 - L2CAP: reject BR/EDR signaling packets over MTUsig
 - RFCOMM: validate skb length in MCC handlers
 - RFCOMM: hold listener socket in rfcomm_connect_ind()
 - ISO: Fix not releasing hdev reference on iso_conn_big_sync
 - ISO: Fix a use-after-free of the hci_conn pointer
 - ISO: Fix data-race on iso_pi fields in hci_get_route calls
 - SCO: Fix data-race on sco_pi fields in sco_connect
 - BNEP: reject short frames before parsing

* tag 'for-net-2026-06-03' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth:
  Bluetooth: MGMT: Fix backward compatibility with userspace
  Bluetooth: SCO: Fix data-race on sco_pi fields in sco_connect
  Bluetooth: ISO: Fix data-race on iso_pi fields in hci_get_route calls
  Bluetooth: ISO: Fix a use-after-free of the hci_conn pointer
  Bluetooth: ISO: Fix not releasing hdev reference on iso_conn_big_sync
  Bluetooth: fix memory leak in error path of hci_alloc_dev()
  Bluetooth: bnep: reject short frames before parsing
  Bluetooth: hci_sync: reject oversized Broadcast Announcement prepend
  Bluetooth: L2CAP: reject BR/EDR signaling packets over MTUsig
  Bluetooth: RFCOMM: validate skb length in MCC handlers
  Bluetooth: MGMT: validate advertising TLV before type checks
  Bluetooth: RFCOMM: hold listener socket in rfcomm_connect_ind()
====================

Link: https://patch.msgid.link/20260603162714.342496-1-luiz.dentz@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-03 19:07:47 -07:00
Jakub Kicinski ac05609982 Merge tag 'wireless-2026-06-03' of https://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless
Johannes Berg says:

====================
Things are finally quieting down:
 - iwlwifi:
   - FW reset handshake removal for older devices
   - NIC access fix in fast resume
   - avoid too large command for some BIOSes
   - fix TX power constraints in AP mode
 - cfg80211:
   - fix netlink parse overflow
   - fix potential 6 GHz scan memory leak
   - enforce HE/EHT consistency to avoid mac80211 crash
 - mac80211: guard radiotap antenna parsing

* tag 'wireless-2026-06-03' of https://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless:
  wifi: cfg80211: enforce HE/EHT cap/oper consistency
  wifi: fix leak if split 6 GHz scanning fails
  wifi: mac80211: limit injected antenna index in ieee80211_parse_tx_radiotap
  wifi: nl80211: reject oversized EMA RNR lists
  wifi: iwlwifi: pcie: simplify the resume flow if fast resume is not used
  wifi: iwlwifi: mvm: avoid oversized UATS command copy
  wifi: iwlwifi: mld: send tx power constraints before link activation
  wifi: iwlwifi: mvm: don't support the reset handshake for old firmwares
====================

Link: https://patch.msgid.link/20260603113208.171874-3-johannes@sipsolutions.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-03 19:07:35 -07:00
Eric Dumazet a02a765bd5 mptcp: change mptcp_established_options() to return opt_size
Instead of passing opt_size address to mptcp_established_options(),
change this function to return it by value.

This removes the need for an expensive stack canary in
tcp_established_options() when CONFIG_STACKPROTECTOR_STRONG=y.

$ scripts/bloat-o-meter -t vmlinux.old vmlinux.new
add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-92 (-92)
Function                                     old     new   delta
tcp_options_write.isra                      1423    1407     -16
mptcp_established_options                   2746    2720     -26
tcp_established_options                      553     503     -50
Total: Before=22110750, After=22110658, chg -0.00%

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260602125138.2317015-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-03 19:04:40 -07:00
Matthieu Baerts (NGI0) bd34fa0257 mptcp: add-addr: always drop other suboptions
When an ADD_ADDR needs to be sent, it could be prepared if there is
enough remaining space and even if the packet is not a pure ACK. But it
would be dropped soon after.

Indeed, in mptcp_pm_add_addr_signal(), there is enough space to fit a
DSS of 20 octets and an ADD_ADDR echo containing an IPv4 address on 8
octets for example. In this case, the packet would be prepared, the
MPTCP_ADD_ADDR_ECHO bit would be removed from pm->addr_signal, but the
option would be silently dropped in mptcp_established_options_add_addr()
not to override DSS info in the union from 'struct mptcp_out_options',
and also because mptcp_write_options() will enforce mutually exclusion
with DSS.

Instead, don't even try to send an ADD_ADDR if it is not a pure ACK.
Retry for each new packet until a pure-ACK is emitted. That's fine to do
that, because each time an ADD_ADDR (echo) is scheduled, a pure ACK is
queued.

This also simplifies the code, and the skb checks can be done earlier,
before the lock.

Note: also, since commit 6d0060f600 ("mptcp: Write MPTCP DSS headers
to outgoing data packets"), opts->ahmac would not have been set to 0
when other suboptions were not dropped, and when sending an ADD_ADDR
echo. That would have resulted in sending an ADD_ADDR using garbage
info, where there was not enough space, instead of an echo one without
the ADD_ADDR HMAC.

Fixes: 1bff1e43a3 ("mptcp: optimize out option generation")
Cc: stable@vger.kernel.org
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260602-net-mptcp-misc-fixes-7-1-rc7-v2-11-856831229976@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-03 19:04:27 -07:00
Paolo Abeni 5e939544f9 mptcp: fix uninit-value in mptcp_established_options
syzbot reported the following uninit splat:

  BUG: KMSAN: uninit-value in mptcp_write_data_fin net/mptcp/options.c:542 [inline]
  BUG: KMSAN: uninit-value in mptcp_established_options_dss net/mptcp/options.c:590 [inline]
  BUG: KMSAN: uninit-value in mptcp_established_options+0x112f/0x3530 net/mptcp/options.c:874
   mptcp_write_data_fin net/mptcp/options.c:542 [inline]
   mptcp_established_options_dss net/mptcp/options.c:590 [inline]
   mptcp_established_options+0x112f/0x3530 net/mptcp/options.c:874
   tcp_established_options+0x312/0xcc0 net/ipv4/tcp_output.c:1192
   __tcp_transmit_skb+0x5dc/0x5fe0 net/ipv4/tcp_output.c:1575
   __tcp_send_ack+0x967/0xad0 net/ipv4/tcp_output.c:4499
   tcp_send_ack+0x3d/0x60 net/ipv4/tcp_output.c:4505
   mptcp_subflow_shutdown+0x164/0x690 net/mptcp/protocol.c:3137
   mptcp_check_send_data_fin+0x31b/0x3d0 net/mptcp/protocol.c:3218
   __mptcp_wr_shutdown net/mptcp/protocol.c:3234 [inline]
   __mptcp_close+0x860/0x1360 net/mptcp/protocol.c:3313
   mptcp_close+0x42/0x260 net/mptcp/protocol.c:3367
   inet_release+0x1ee/0x2a0 net/ipv4/af_inet.c:442
   __sock_release net/socket.c:722 [inline]
   sock_close+0xd6/0x2f0 net/socket.c:1514
   __fput+0x60e/0x1010 fs/file_table.c:510
   ____fput+0x25/0x30 fs/file_table.c:538
   task_work_run+0x208/0x2b0 kernel/task_work.c:233
   resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
   __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
   exit_to_user_mode_loop+0x306/0x1b60 kernel/entry/common.c:98
   __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
   syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
   syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
   __do_fast_syscall_32+0x2c7/0x460 arch/x86/entry/syscall_32.c:310
   do_fast_syscall_32+0x37/0x80 arch/x86/entry/syscall_32.c:332
   do_SYSENTER_32+0x1f/0x30 arch/x86/entry/syscall_32.c:370
   entry_SYSENTER_compat_after_hwframe+0x84/0x8e

  Local variable opts created at:
   __tcp_transmit_skb+0x4d/0x5fe0 net/ipv4/tcp_output.c:1536
   __tcp_send_ack+0x967/0xad0 net/ipv4/tcp_output.c:4499

The output path currently omits initializing the mptcp extension
`use_map` flag in a few corner cases.

Address the issue always zeroing all the extensions flags before
eventually initializing the individual bits. To that extent, introduce
and use a struct_group to avoid multiple bitwise operations.

Fixes: cfcceb7a39 ("tcp: shrink per-packet memset in __tcp_transmit_skb()")
Cc: stable@vger.kernel.org
Reported-by: syzbot+ff020673c5e3d94d9478@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=ff020673c5e3d94d9478
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260602-net-mptcp-misc-fixes-7-1-rc7-v2-10-856831229976@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-03 19:04:27 -07:00
Gang Yan c378b1a6f8 mptcp: check desc->count in read_sock
__tcp_read_sock() checks desc->count after each skb is consumed and
breaks the loop when it reaches 0. The MPTCP variant lacks this check.

This is a functional bug, other subsystems also rely on this check:
TLS strparser sets desc->count to 0 once a full TLS record is assembled
and depends on this break to stop reading.

Add the same desc->count check to __mptcp_read_sock(), mirroring
__tcp_read_sock().

Fixes: 250d9766a9 ("mptcp: implement .read_sock")
Cc: stable@vger.kernel.org
Co-developed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Gang Yan <yangang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260602-net-mptcp-misc-fixes-7-1-rc7-v2-9-856831229976@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-03 19:04:26 -07:00
Matthieu Baerts (NGI0) 7690137e70 mptcp: sockopt: set sockopt on all subflows
The mptcp_setsockopt_all_sf(), currently used only with TCP_MAXSEG,
stopped when one subflow returned an error.

Even if it is not wrong, this is different from the other helpers trying
to set the option on all subflows, and then returning an error if at
least one of them had an issue.

Follow this behaviour, for a question of uniformity.

Fixes: 51c5fd09e1 ("mptcp: add TCP_MAXSEG sockopt support")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260602-net-mptcp-misc-fixes-7-1-rc7-v2-8-856831229976@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-03 19:04:26 -07:00
Matthieu Baerts (NGI0) 57132affbc mptcp: sockopt: check timestamping ret value
sock_set_timestamping() can fail for different reasons. The returned
value should then be checked.

If sock_set_timestamping() fails for at least one subflow, the first
error is now reported to the userspace, similar to what is done with
other socket options.

Fixes: 9061f24bf8 ("mptcp: sockopt: propagate timestamp request to subflows")
Cc: stable@vger.kernel.org
Reported-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Closes: https://lore.kernel.org/willemdebruijn.kernel.178a41a53d041@gmail.com
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260602-net-mptcp-misc-fixes-7-1-rc7-v2-7-856831229976@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-03 19:04:26 -07:00
Tao Cui 14e9fea30b mptcp: pm: fix extra_subflows underflow on userspace PM subflow creation
The userspace PM increments extra_subflows after __mptcp_subflow_connect()
succeeds, but __mptcp_subflow_connect() calls mptcp_pm_close_subflow()
on failure to roll back the pre-increment done by the kernel PM's fill_*()
helpers. Because the userspace PM hasn't incremented yet at that point,
this decrement is spurious and causes extra_subflows to underflow.

Fix it by aligning the userspace PM with the kernel PM: increment
extra_subflows before calling __mptcp_subflow_connect(), so the existing
error path in subflow.c correctly rolls it back on failure. Also simplify
the error handling by taking pm.lock only when needed for cleanup.

Fixes: 77e4b94a3d ("mptcp: update userspace pm infos")
Cc: stable@vger.kernel.org
Signed-off-by: Tao Cui <cuitao@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260602-net-mptcp-misc-fixes-7-1-rc7-v2-5-856831229976@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-03 19:04:26 -07:00
Paolo Abeni da23be77e1 mptcp: allow subflow rcv wnd to shrink
In MPTCP connection, the `window` field in the TCP header refers to the
MPTCP-level rcv_nxt and it's right edge should not move backward. Such
constraint is enforced at DSS option generation time.

At the same time, the TCP stack ensures independently that the TCP-level
rcv wnd right's edge does not move backward. That in turn causes artificial
inflating of the MPTCP rcv window when the incoming data is acked at the
TCP level and is OoO in the MPTCP sequence space (or lands in the backlog).

As a consequence, the incoming traffic can exceed the receiver rcvbuf size
even when the sender is not misbehaving.

Prevent such scenario forcibly allowing the TCP subflow to shrink the
TCP-level rcv wnd regardless of the current netns setting.

Fixes: f3589be0c4 ("mptcp: never shrink offered window")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260602-net-mptcp-misc-fixes-7-1-rc7-v2-4-856831229976@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-03 19:04:26 -07:00
Paolo Abeni 8ab24fdebc mptcp: close TOCTOU race while computing rcv_wnd
The MPTCP output path access locklessly the MPTCP-level ack_seq
in multiple times, using possibly different values for the data_ack
in the DSS option and to compute the announced rcv wnd for the same
packet.

Refactor the cote to avoid inconsistencies which may confuse the
peer. Also ensure that the MPTCP level rcv wnd is updated only when
the egress packet actually contains a DSS ack.

Fixes: fa3fe2b150 ("mptcp: track window announced to peer")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260602-net-mptcp-misc-fixes-7-1-rc7-v2-3-856831229976@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-03 19:04:25 -07:00
Paolo Abeni d1918b36ed mptcp: fix retransmission loop when csum is enabled
Sashiko noted that retransmission with csum enabled can actually
transmit new data, but currently the relevant code does not update
accordingly snd_nxt.

The may cause incoming ack drop and an endless retransmission loop.

Address the issue incrementing snd_nxt as needed.

Fixes: 4e14867d5e ("mptcp: tune re-injections for csum enabled mode")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260602-net-mptcp-misc-fixes-7-1-rc7-v2-2-856831229976@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-03 19:04:25 -07:00
Paolo Abeni 9d8d28738f mptcp: fix missing wakeups in edge scenarios
The mptcp_recvmsg() can fill MPTCP socket receive queue via
mptcp_move_skbs(), but currently does not try to wakeup any listener,
because the same process is going to check the receive queue soon.

When multiple threads are reading from the same fd, the above can
cause stall. Add the missing wakeup.

Fixes: 6771bfd9ee ("mptcp: update mptcp ack sequence from work queue")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260602-net-mptcp-misc-fixes-7-1-rc7-v2-1-856831229976@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-03 19:04:25 -07:00
Eric Dumazet 3070d0294e ipv4: raw: remove six obsolete EXPORT_SYMBOL_GPL()
IPv6 can not be a module anymore, we no longer need to export:

- raw_hash_sk()
- raw_unhash_sk()
- raw_abort()
- raw_seq_start()
- raw_seq_next()
- raw_seq_stop()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20260602165036.2712408-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-03 18:53:37 -07:00
Eric Dumazet d3915a1f5a ipv4: restrict IPOPT_SSRR and IPOPT_LSRR options
This patch restricts setting Loose Source and Record Route (LSRR)
and Strict Source and Record Route (SSRR) IP options to users
with CAP_NET_RAW capability.

This prevents unprivileged applications from forcing packets to route
through attacker-controlled nodes to leak TCP ISN and possibly other
protocol information.

While LSRR and SSRR are commonly filtered in many network environments,
they may still be supported and forwarded along some network paths.

RFC 7126 (Recommendations on Filtering of IPv4 Packets Containing
IPv4 Options) recommend to drop these options in 4.3 and 4.4.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: Tamir Shahar <tamirthesis@gmail.com>
Reported-by: Amit Klein <aksecurity@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260602161547.2642155-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-03 18:53:14 -07:00