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In case of early freeing an unwanted TCP-MD5 key on TCP-AO connect(),
md5sig_info is freed right away (and set to NULL). Later, at
the moment of socket destruction, the static branch counter
is not getting decremented.
Add a missing decrement for TCP-MD5 static branch.
Reported-by: Qihang <q.h.hack.winter@gmail.com>
Fixes: 0aadc73995d0 ("net/tcp: Prevent TCP-MD5 with TCP-AO being set")
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Link: https://patch.msgid.link/20260625-tcp-md5-connect-v3-3-1fd313d6c1e0@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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The md5+ao reconciliation in tcp_connect() (net/ipv4/tcp_output.c)
has two symmetric branches:
if (needs_md5) {
tcp_ao_destroy_sock(sk, false);
} else if (needs_ao) {
tcp_clear_md5_list(sk);
kfree(rcu_replace_pointer(tp->md5sig_info, NULL, ...));
}
Both branches free a per-socket auth-info object while the socket is
in TCP_SYN_SENT and is already on the inet ehash (inserted by
inet_hash_connect() in tcp_v4_connect()). Both branches are reachable
by softirq RX-path readers that load the corresponding info pointer
via implicit RCU before bh_lock_sock_nested() is taken.
The needs_md5 branch is fixed in the prior patch by re-introducing
the call_rcu() free in tcp_ao_destroy_sock(): the equivalent per-key
loop runs inside tcp_ao_info_free_rcu(), the RCU callback, so by the
time it frees each tcp_ao_key all softirq readers that captured the
container have already completed rcu_read_unlock().
The needs_ao branch is not symmetric in the same way. The container
free can be deferred via kfree_rcu(md5sig, rcu) -- struct
tcp_md5sig_info already has the required rcu member
(include/net/tcp.h:1999-2002), and the rest of the tree already does
this in the tcp_md5sig_info_add() rollback paths
(net/ipv4/tcp_ipv4.c:1410, 1436). But the per-key teardown is done
by tcp_clear_md5_list() in process context BEFORE the container's
RCU grace period: it walks &md5sig->head and frees each
tcp_md5sig_key with bare hlist_del + kfree. A concurrent softirq
reader in __tcp_md5_do_lookup() / __tcp_md5_do_lookup_exact()
(tcp_ipv4.c:1253, 1298) walks the same list via
hlist_for_each_entry_rcu() and races with that bare kfree on the
keys themselves -- a per-key slab use-after-free of the same class
as the TCP-AO bug, on the same race window.
Fix this in two halves:
1. Convert the bare kfree() in tcp_connect() to kfree_rcu() so the
md5sig_info container joins the rest of the md5sig lifecycle.
The local-variable lift is mechanical and required because
kfree_rcu() is a macro that expects an lvalue.
2. Make tcp_clear_md5_list() RCU-safe by replacing hlist_del +
kfree(key) with hlist_del_rcu + kfree_rcu(key, rcu). struct
tcp_md5sig_key already carries the rcu member
(include/net/tcp.h:1995) and tcp_md5_do_del()
(net/ipv4/tcp_ipv4.c:1456) already uses kfree_rcu, so this
restores the lifecycle invariant the rest of the file follows
rather than introducing a one-off.
The other caller of tcp_clear_md5_list() is tcp_md5_destruct_sock()
(net/ipv4/tcp.c:412), which runs from the sock destructor when the
socket is already unhashed and unreachable; the extra grace period
there is unnecessary but harmless. Making the helper unconditionally
RCU-safe is the cleaner contract.
The needs_ao branch is not reachable by the userns reproducer used
to demonstrate the AO-side splat (the repro installs both keys but
ends up in the needs_md5 branch because the connect peer matches
the MD5 key, not the AO key); however the symmetric race exists
and a maintainer touching this code should not have to think about
which branch escapes RCU and which one does not.
Fixes: 51e547e8c89c ("tcp: Free TCP-AO/TCP-MD5 info/keys without RCU")
Cc: stable@vger.kernel.org # v6.18+
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com>
Reviewed-by: Dmitry Safonov <dima@arista.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
[also credits to Qihang, who found that this races with tcp-diag]
Reported-by: Qihang <q.h.hack.winter@gmail.com>
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Link: https://patch.msgid.link/20260625-tcp-md5-connect-v3-2-1fd313d6c1e0@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Commit 51e547e8c89c ("tcp: Free TCP-AO/TCP-MD5 info/keys without RCU")
removed the call_rcu() callback from tcp_ao_destroy_sock(), arguing that
"the destruction of info/keys is delayed until the socket destructor"
and therefore "no one can discover it anymore".
That argument does not hold for the call site in tcp_connect()
(net/ipv4/tcp_output.c:4327-4332). At that point the socket is in
TCP_SYN_SENT, has already been inserted into the inet ehash by
inet_hash_connect() in tcp_v4_connect(), and is therefore very much
discoverable: any softirq running tcp_v4_rcv() on another CPU can take
the socket out of the ehash, walk into tcp_inbound_hash(), and load
tp->ao_info via implicit RCU before bh_lock_sock_nested() is taken on
the destroying CPU.
The reader path then enters __tcp_ao_do_lookup() (net/ipv4/tcp_ao.c:208)
which re-loads tp->ao_info via rcu_dereference_check(); the re-load can
still observe the (about-to-be-freed) pointer because there is no
synchronize_rcu() between rcu_assign_pointer(tp->ao_info, NULL) and
tcp_ao_info_free() in tcp_ao_destroy_sock(). The captured pointer is
then walked at line 223:
hlist_for_each_entry_rcu(key, &ao->head, node, ...)
The writer's synchronous kfree() is free to complete between the line
218 re-fetch and the line 223 hlist iteration. The slab is reused
(or simply LIST_POISON1-stamped if not yet reused) and the iteration
walks attacker-controlled or poison memory in softirq context.
Reproducer (no debug shim, stock x86_64 v7.1-rc2 SMP+KASAN, QEMU+KVM):
an unprivileged uid=1000 process inside CLONE_NEWUSER|CLONE_NEWNET
installs TCP_MD5SIG + TCP_AO_ADD_KEY on a TCP socket, sprays forged
TCP-AO segments toward its eventual 4-tuple via raw sockets, then
calls connect(). The md5-wins reconciliation in tcp_connect() fires
tcp_ao_destroy_sock(); the softirq backlog reader on the loopback
NAPI path crashes on the freed ao->head.first walk:
Oops: general protection fault, probably for non-canonical
address 0xfbd59c000000002f
KASAN: maybe wild-memory-access in range
[0xdead000000000178-0xdead00000000017f]
CPU: 0 UID: 1000 PID: 100 Comm: repro_userns
RIP: 0010:__tcp_ao_do_lookup+0x107/0x1c0
Call Trace: <IRQ>
__tcp_ao_do_lookup+0x107/0x1c0
tcp_ao_inbound_lookup.constprop.0+0x12a/0x200
tcp_inbound_ao_hash+0x5ea/0x1520
tcp_inbound_hash+0x7ce/0x1240
tcp_v4_rcv+0x1e7a/0x3e10
...
Restore the RCU grace period: re-add struct rcu_head to tcp_ao_info
and replace the synchronous tcp_ao_info_free() with a call_rcu()
callback. Readers that captured tp->ao_info before rcu_assign_pointer
NULLed it now see the object remain valid until rcu_read_unlock().
With the patch applied the reproducer runs cleanly for 2000 iterations
on the same kernel build.
Fixes: 51e547e8c89c ("tcp: Free TCP-AO/TCP-MD5 info/keys without RCU")
Cc: stable@vger.kernel.org # v6.18+
Reviewed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Link: https://patch.msgid.link/20260625-tcp-md5-connect-v3-1-1fd313d6c1e0@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Jakub Kicinski:
"Including fixes from netfilter and IPsec.
Current release - regressions:
- do not acquire dev->tx_global_lock in netdev_watchdog_up()
- ethtool: keep rtnl_lock for ops using ethtool_op_get_link()
- fix deadlock in nested UP notifier events
Current release - new code bugs:
- eth:
- cn20k: fix subbank free list indexing for search order
- airoha: fix BQL underflow in shared QDMA TX ring
Previous releases - regressions:
- netfilter:
- flowtable: fix offloaded ct timeout never being extended
- nf_conncount: prevent connlimit drops for early confirmed ct
Previous releases - always broken:
- require CAP_NET_ADMIN in the originating netns when modifying
cross-netns devices
- report NAPI thread PID in the caller's pid namespace
- mac802154: fix dirty frag in in-place crypto for IOT radios
- sctp: hold socket lock when dumping endpoints in sctp_diag, avoid
an overflow
- eth: gve: fix header buffer corruption with header-split and HW-GRO
- af_key: initialize alg_key_len for IPComp states, prevent OOB read"
* tag 'net-7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (213 commits)
selftests: bonding: add a test for VLAN propagation over a bonded real device
vlan: defer real device state propagation to netdev_work
net: add the driver-facing netdev_work scheduling API
net: turn the rx_mode work into a generic netdev_work facility
net: ethtool: keep rtnl_lock for ops using ethtool_op_get_link()
rxrpc: Fix rxrpc_rotate_tx_rotate() to check there's something to rotate
rxrpc: Fix leak of released call in recvmsg(MSG_PEEK)
rxrpc: Fix socket notification race
rxrpc: Fix potential infinite loop in rxrpc_recvmsg()
rxrpc: Fix oob challenge leak in cleanup after notification failure
rxrpc: Fix the reception of a reply packet before data transmission
afs: Fix uncancelled rxrpc OOB message handler
afs: Fix further netns teardown to cancel the preallocation charger
rxrpc: Fix double unlock in rxrpc_recvmsg()
rxrpc: Fix leak of connection from OOB challenge
rxrpc: Fix ACKALL packet handling
net: hns3: differentiate autoneg default values between copper and fiber
net: hns3: fix permanent link down deadlock after reset
net: hns3: refactor MAC autoneg and speed configuration
net: hns3: unify copper port ksettings configuration path
...
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Yue Sun reported a use-after-free and debugobjects warning in
udp_tunnel_nic_device_sync_work() during concurrent device operations.
The workqueue core clears the internal pending bit before invoking the
worker. At that point, a concurrent thread can queue the work again.
When the already running worker eventually clears the work_pending flag
to 0, it mistakenly clears the flag for the newly queued instance.
udp_tunnel_nic_unregister() then observes work_pending as 0 and frees
the structure while the second work item is still active in the queue,
leading to UAF.
Fix this by returning early in udp_tunnel_nic_device_sync() if
work_pending is already set, preventing redundant work queueing.
Fixes: cc4e3835eff4 ("udp_tunnel: add central NIC RX port offload infrastructure")
Reported-by: Yue Sun <samsun1006219@gmail.com>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260625065938.654652-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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In tcp_ao_delete_key(), the del_async path skips the current_key
and rnext_key validity checks present in the synchronous path,
assuming these pointers are always NULL on LISTEN sockets. However,
if a key was added with set_current=1/set_rnext=1 while the socket
was in CLOSE state, current_key and rnext_key will be non-NULL
after listen() transitions the socket to LISTEN.
When such a key is deleted with del_async=1, hlist_del_rcu() and
call_rcu() free the key without clearing the dangling pointers.
After the RCU grace period, getsockopt(TCP_AO_INFO) dereferences
current_key->sndid and rnext_key->rcvid from freed slab memory.
Clear current_key and rnext_key in the del_async path when they
reference the key being deleted.
Fixes: d6732b95b6fb ("net/tcp: Allow asynchronous delete for TCP-AO keys (MKTs)")
Signed-off-by: HanQuan <eilaimemedsnaimel@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260623015208.1191687-1-eilaimemedsnaimel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec
Steffen Klassert says:
====================
pull request (net): ipsec 2026-06-22
1) xfrm: use compat translator only for u64 alignment mismatch
Gate the XFRM_USER_COMPAT translator on COMPAT_FOR_U64_ALIGNMENT
so 32-bit compat tasks on arches whose 32-bit ABI already matches
the native 64-bit layout are no longer rejected with -EOPNOTSUPP.
From Sanman Pradhan.
2) net: af_key: initialize alg_key_len for IPComp states
Initialize the alg_key_len to 0 in the IPComp branch of
pfkey_msg2xfrm_state() so an uninitialized value cannot drive
xfrm_alg_len() into a slab-out-of-bounds kmemdup during
XFRM_MSG_MIGRATE. From Zijing Yin.
3) xfrm: Fix dev use-after-free in xfrm async resumption
Stash the original skb->dev and extend the RCU critical section
across xfrm_rcv_cb() and transport_finish() to prevent a
tunnel-device UAF and original-device refcount leak when a
callback replaces skb->dev. From Dong Chenchen.
4) xfrm: Fix xfrm state cache insertion race
Move the state-validity check inside xfrm_state_lock in the
input state cache insertion path so a state cannot be killed
between the check and the insert. From Herbert Xu.
5) xfrm: annotate data-races around xfrm_policy_count[] and xfrm_policy_default[]
Add READ_ONCE()/WRITE_ONCE() annotations on xfrm_policy_count
and xfrm_policy_default to silence the KCSAN data race reported
on net->xfrm.policy_count. From Eric Dumazet.
6) espintcp: use sk_msg_free_partial to fix partial send
Replace the manual skmsg accounting in espintcp with
sk_msg_free_partial() so the skmsg stays consistent on every
iteration and the partial-send accounting bugs go away.
From Sabrina Dubroca.
7) xfrm: validate selector family and prefixlen during match
Reject mismatched address families in xfrm_selector_match() and
bound prefixlen in addr4_match()/addr_match() to prevent the
shift-out-of-bounds syzbot reported when an AF_UNSPEC selector
with a large prefixlen is matched against an IPv4 flow.
From Eric Dumazet.
* tag 'ipsec-2026-06-22' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec:
xfrm: validate selector family and prefixlen during match
espintcp: use sk_msg_free_partial to fix partial send
xfrm: annotate data-races around xfrm_policy_count[] and xfrm_policy_default[]
xfrm: Fix xfrm state cache insertion race
xfrm: Fix dev use-after-free in xfrm async resumption
net: af_key: initialize alg_key_len for IPComp states
xfrm: use compat translator only for u64 alignment mismatch
====================
Link: https://patch.msgid.link/20260622075726.29685-1-steffen.klassert@secunet.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
The following patchset contains Netfilter fixes for net. This batches
fixes for real crashes with trivial/correctness fixes. There is too
a rework of the conntrack expectation timeout strategy to deal with
a possible race when removing an expectation.
1) Fix the incorrect flowtable timeout extension for entries in
hw offload, from Adrian Bente. This is correcting a defect in
the functionality, no crash.
2) Hold reference to device under the fake dst in br_netfilter,
from Haoze Xie. This is fixing a possible UaF if the device
is removed while packet is sitting in nfqueue.
3) Reject template conntrack in xt_cluster, otherwise access to
uninitialize conntrack fields are possible leading to WARN_ON
due to unset layer 3 protocol. From Wyatt Feng.
4) Make sure the IPv6 tunnel header is in the linear skb data
area before pulling. While at it remove incomplete NEXTHDR_DEST
support. From Lorenzo Bianconi. This possibly leading to crash
if IPv4 header is not in the linear area.
5) Use test_bit_acquire in ipset hash set to avoid reordering
of subsequent memory access. This is addressing a LLM related
report, no crash has been observed. From Jozsef Kadlecsik.
6) Use test_bit_acquire in ipset bitmap set too, for the same
reason as in the previous patch, from Jozsef Kadlecsik.
7) Call kfree_rcu() after rcu_assign_pointer() to address a
possible UaF if kfree_rcu() runs inmediately, which to my
understanding never happens. Never observed in practise,
reported by LLM. Also from Jozsef Kadlecsik.
8) Use disable_delayed_work_sync() instead cancel_delayed_work_sync()
to avoid that ipset GC handler re-queues work as reported by LLM.
From Jozsef Kadlecsik. This is for correctness.
9) Restore the check in nft_payload for exceeding payloda offset
over 2^16. From Florian Westphal. This fixes a silent truncation,
not a big deal, but better be assertive and reject it.
10) Validate NFT_META_BRI_IIFHWADDR can only run from bridge
prerouting. From Florian Westphal. Harmless but it could allow
to read bytes from skb->cb.
11) Zero out destination hardware address during the flowtable
path setup, also from Florian. This is a correctness fix, LLM
points that possible infoleak can happen but topology to achieve
it is not clear.
12) Skip IPv4 options if present when building the IPV4 reject reply.
Otherwise bytes in the IPv4 options header can be sent back to
origin where the ICMP header is being expected. Again from
Florian Westphal.
13) Replace timer API for expectation by GC worker approach. This
is implicitly fixing a race between nf_ct_remove_expectations()
which might fail to remove the expectation due to timer_del()
returning false because timer has expired and callback is
being run concurrently. This fix is addressing a crash that has
been already reported with a reproducer.
14) Check if br_vlan_get_pvid_rcu() fails, otherwise possible stack
infoleak of 4-bytes. From Florian Westphal.
* tag 'nf-26-06-21' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
netfilter: nft_meta_bridge: fix NFT_META_BRI_IIFPVID stack leak
netfilter: nf_conntrack_expect: use conntrack GC to reap expectations
netfilter: nf_reject: skip iphdr options when looking for icmp header
netfilter: nft_flow_offload: zero device address for non-ether case
netfilter: nft_meta_bridge: add validate callback for get operations
netfilter: nft_payload: reject offsets exceeding 65535 bytes
netfilter: ipset: make sure gc is properly stopped
netfilter: ipset: fix order of kfree_rcu() and rcu_assign_pointer()
netfilter: ipset: Don't use test_bit() in lockless RCU readers in bitmap types
netfilter: ipset: Don't use test_bit() in lockless RCU readers in hash types
netfilter: flowtable: fix and simplify IP6IP6 tunnel handling
netfilter: xt_cluster: reject template conntracks in hash match
netfilter: nf_queue: pin bridge device while NFQUEUE holds fake dst
netfilter: flowtable: fix offloaded ct timeout never being extended
====================
Link: https://patch.msgid.link/20260620222738.112506-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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In __ip_append_data(), when the paged-allocation branch is taken,
alloclen and pagedlen are computed as
alloclen = fragheaderlen + transhdrlen;
pagedlen = datalen - transhdrlen;
datalen already includes fraggap, but the fraggap bytes carried over
from the previous skb are copied into the new skb's linear area at
offset transhdrlen by the subsequent skb_copy_and_csum_bits(). The
linear area is therefore undersized by fraggap bytes while pagedlen is
overstated by the same amount.
The non-paged branch sets alloclen to fraglen, which already accounts
for fraggap because datalen does. Bring the paged branch in line by
adding fraggap to alloclen and subtracting it from pagedlen.
After this adjustment, copy no longer collapses to -fraggap on the
paged path, so remove the stale comment describing that old arithmetic.
Fixes: 8eb77cc73977 ("ipv4: avoid partial copy for zc")
Signed-off-by: Jungwoo Lee <jwlee2217@gmail.com>
Signed-off-by: Wongi Lee <qw3rtyp0@gmail.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/ajFR1eLAIs42TN3g@DESKTOP-19IMU7U.localdomain
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Not a big deal but this hould have used the real ip header length and not the
base header size. As-is, if there are options then
nf_skb_is_icmp_unreach() result will be random.
Fixes: db99b2f2b3e2 ("netfilter: nf_reject: don't reply to icmp error messages")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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Reject invalid `net.ipv4.tcp_reordering` values before they reach TCP
socket state. The sysctl is stored as an `int` but copied into the
`u32` `tp->reordering` field for new sockets, so negative writes wrap
to large values.
With `tcp_mtu_probing=2`, the wrapped value can overflow the
`tcp_mtu_probe()` size calculation and drive the MTU probing path into
an out-of-bounds read. Route `tcp_reordering` writes through
`proc_dointvec_minmax()` and require it to be at least 1. Also require
`tcp_max_reordering` to be at least 1 so the configured maximum cannot
become negative either.
When registering the table for a non-init network namespace, relocate
`extra2` pointers that refer into `init_net.ipv4` so the
`tcp_reordering` upper bound follows that namespace's
`tcp_max_reordering`.
Harden `tcp_mtu_probe()` itself by computing `size_needed` as `u64`.
This keeps the send queue and window checks from being bypassed through
signed integer overflow.
Fixes: 91cc17c0e5e5 ("[TCP]: MTUprobe: receiver window & data available checks fixed")
Cc: stable@vger.kernel.org
Reported-by: Yuan Tan <yuantan098@gmail.com>
Reported-by: Zhengchuan Liang <zcliangcn@gmail.com>
Reported-by: Xin Liu <bird@lzu.edu.cn>
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Wyatt Feng <bronzed_45_vested@icloud.com>
Signed-off-by: Ren Wei <n05ec@lzu.edu.cn>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/1a5b7e1ef4d70fbad8c8ee0b82d8405f3c964a3d.1781395200.git.bronzed_45_vested@icloud.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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vti_changelink() operates on at most two netns, dev_net(dev) and the
tunnel link netns t->net. They differ once the device is created in or
moved to a netns other than the one the request runs in. The rtnl
changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a
caller privileged there but not in t->net can rewrite a tunnel that
lives in t->net.
Gate vti_changelink() on rtnl_dev_link_net_capable() at its top,
before any attribute is parsed.
Reported-by: Xiao Liang <shaw.leon@gmail.com>
Closes: https://lore.kernel.org/netdev/CABAhCOSzP1vaThGV35_VnsRCb=87_CPjPVsTHbq905k8A+BuUg@mail.gmail.com/
Fixes: 895de9a3488a ("vti4: Enable namespace changing")
Cc: stable@vger.kernel.org
Signed-off-by: Maoyi Xie <maoyixie.tju@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260612085941.3158249-4-maoyixie.tju@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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ipip_changelink() operates on at most two netns, dev_net(dev) and the
tunnel link netns t->net. They differ once the device is created in or
moved to a netns other than the one the request runs in. The rtnl
changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a
caller privileged there but not in t->net can rewrite a tunnel that
lives in t->net.
Gate ipip_changelink() on rtnl_dev_link_net_capable() at its top,
before any attribute is parsed.
Reported-by: Xiao Liang <shaw.leon@gmail.com>
Closes: https://lore.kernel.org/netdev/CABAhCOSzP1vaThGV35_VnsRCb=87_CPjPVsTHbq905k8A+BuUg@mail.gmail.com/
Fixes: 6c742e714d8c ("ipip: add x-netns support")
Cc: stable@vger.kernel.org
Signed-off-by: Maoyi Xie <maoyixie.tju@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260612085941.3158249-3-maoyixie.tju@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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A tunnel changelink() operates on at most two netns, dev_net(dev) and
the tunnel link netns t->net. They differ once the device is created in
or moved to a netns other than the one the request runs in. The rtnl
changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a
caller privileged there but not in t->net can rewrite a tunnel that
lives in t->net.
Add rtnl_dev_link_net_capable() next to rtnl_get_net_ns_capable() in
net/core/rtnetlink.c. It requires CAP_NET_ADMIN in the link netns and is
skipped when the link netns is dev_net(dev), where the rtnl path already
checked it. The other patches in this series use the same helper.
Gate ipgre_changelink() and erspan_changelink() with it, at the top of
the op before any attribute is parsed, because the parsers update live
tunnel fields first. ipgre_netlink_parms() sets t->collect_md before
ip_tunnel_changelink() runs.
Commit 8b484efd5cb4 ("ip6: vti: Use ip6_tnl.net in
vti6_siocdevprivate().") added the same check on the ioctl path. This
adds it on RTM_NEWLINK.
Reported-by: Xiao Liang <shaw.leon@gmail.com>
Closes: https://lore.kernel.org/netdev/CABAhCOSzP1vaThGV35_VnsRCb=87_CPjPVsTHbq905k8A+BuUg@mail.gmail.com/
Fixes: b57708add314 ("gre: add x-netns support")
Cc: stable@vger.kernel.org
Signed-off-by: Maoyi Xie <maoyixie.tju@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260612085941.3158249-2-maoyixie.tju@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Alexei Starovoitov:
"Major changes:
- Recover from BPF arena page faults using a scratch page and add
ptep_try_set() for lockless empty-slot installs on x86 and arm64.
This allows BPF kfuncs to access arena pointers directly.
The 'arena_direct_access' stable branch was created for this work
and was pulled into sched-ext and bpf-next trees (Tejun Heo, Kumar
Kartikeya Dwivedi)
- Lift old restriction and support 6+ arguments in BPF programs and
kfuncs on x86 and arm64 (Yonghong Song, Puranjay Mohan)
Other features and fixes:
- Add 24-bit BTF vlen and reclaim unused bits in the BTF UAPI to ease
addition of new BTF kinds (Alan Maguire)
- Raise the maximum BPF call chain depth from 8 to 16 frames (Alexei
Starovoitov)
- Refactor object relationship tracking in the verifier and fix a
dynptr use-after-free bug (Amery Hung)
- Harden the signed program loader and reject exclusive maps as inner
maps (Daniel Borkmann)
- Replace the verifier min/max bounds fields with a circular number
(cnum) representation and improve 32->64 bit range refinements
(Eduard Zingerman)
- Introduce the arena library and runtime (libarena) with a buddy
allocator, rbtree and SPMC queue data structures, ASAN support and
a parallel test harness. Allow subprograms to return arena pointers
and switch to a BTF type-tag based __arena annotation (Emil
Tsalapatis)
- Cache build IDs in the sleepable stackmap path and avoid faultable
build ID reads under mm locks (Ihor Solodrai)
- Introduce the tracing_multi link to attach a single BPF program to
many kernel functions at once. Allow specifying the uprobe_multi
target via FD (Jiri Olsa)
- Extend the bpf_list family of kfuncs with bpf_list_add/del(), and
bpf_list_is_first/is_last/empty() (Kaitao Cheng)
- Extend the BPF syscall with common attributes support for
prog_load, btf_load and map_create (Leon Hwang)
- Wrap rhashtable as BPF map (Mykyta Yatsenko, Herbert Xu)
- Add sleepable support for tracepoint programs and fix deadlocks in
LRU map due to NMI reentry (Mykyta Yatsenko)
- Fix OOB access in bpf_flow_keys, fix nullness analysis of inner
arrays, enforce write checks for global subprograms (Nuoqi Gui)
- Report the maximum combined stack depth and print a breakdown of
instructions processed per subprogram (Paul Chaignon)
- Add an XDP load-balancer benchmark and arm64 JIT support for stack
arguments (Puranjay Mohan)
- Add kfuncs to traverse over wakeup_sources (Samuel Wu)
- Allow sleepable BPF programs to use LPM trie maps directly (Vlad
Poenaru)
- Many more fixes and cleanups across the verifier, BTF, sockmap,
devmap, bpffs, security hooks, s390/riscv/loongarch JITs,
rqspinlock, libbpf, bpftool, selftests"
* tag 'bpf-next-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (336 commits)
selftests/bpf: Work around llvm stack overflow in crypto progs
selftests/bpf: add test for bpf_msg_pop_data() overflow
bpf, sockmap: fix integer overflow in bpf_msg_pop_data() bounds check
sockmap: Fix use-after-free in udp_bpf_recvmsg()
bpf, sockmap: keep sk_msg copy state in sync
bpf, sockmap: Fix wrong rsge offset in bpf_msg_push_data()
bpf, sockmap: reject overflowing copy + len in bpf_msg_push_data()
selftsets/bpf: Retry map update on helper_fill_hashmap()
selftests/bpf: Add test for sleepable lsm_cgroup rejection
selftests/bpf: Add test to verify the fix for bpf_setsockopt() helper
bpf: Fix bpf_get/setsockopt to tos for ipv4-mapped ipv6 socket
selftests/bpf: Avoid static LLVM linking for cross builds
selftests/bpf: Use common CFLAGS for urandom_read
selftests/bpf: Initialize operation name before use
tools/bpf: build: Append extra cflags
libbpf: Initialize CFLAGS before including Makefile.include
bpftool: Append extra host flags
bpftool: Avoid adding EXTRA_CFLAGS to HOST_CFLAGS
bpftool: Pass host flags to bootstrap libbpf
selftests/bpf: correct CONFIG_PPC64 macro name in comment
...
|
|
syzbot reported use-after-free of net->ipv4.rules_ops. [0]
It can be reproduced with these commands:
while true; do
ip netns add ns1
ip -n ns1 link set dev lo up
ip -n ns1 address add 192.0.2.1/24 dev lo
ip -n ns1 link add name dummy1 up type dummy
ip -n ns1 address add 198.51.100.1/24 dev dummy1
ip -n ns1 rule add ipproto tcp sport 12345 table 12345
ip -n ns1 fou add port 5555 ipproto 47 local 192.0.2.1 peer 198.51.100.2 peer_port 54321
ip netns del ns1
done
The cited commit moved fib4_rules_exit() earlier to ->exit_rtnl(),
but the kernel socket destroyed in ->exit() could eventually reach
__fib_lookup().
I left fib4_rules_exit() in ->exit_rtnl() because fib4_rule_delete()
calls fib_unmerge(), which requires RTNL.
However, when ->delete() is called, ->configure() has already been
called, thus fib_unmerge() in ->delete() has no effect.
Let's remove fib_unmerge() in fib4_rule_delete() and move
fib4_rules_exit() to ->exit().
Many thanks to Ido Schimmel for providing the nice repro very quickly.
Note that we can make fib_rules_ops.delete() return void once
net-next opens.
[0]:
BUG: KASAN: slab-use-after-free in fib_rules_lookup+0x15e/0xeb0 net/core/fib_rules.c:321
Read of size 8 at addr ffff88804ec4c680 by task kworker/u8:21/12641
CPU: 0 UID: 0 PID: 12641 Comm: kworker/u8:21 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: netns cleanup_net
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_address_description+0x55/0x1e0 mm/kasan/report.c:378
print_report+0x58/0x70 mm/kasan/report.c:482
kasan_report+0x117/0x150 mm/kasan/report.c:595
fib_rules_lookup+0x15e/0xeb0 net/core/fib_rules.c:321
__fib_lookup+0x106/0x210 net/ipv4/fib_rules.c:96
ip_route_output_key_hash_rcu+0x294/0x2720 net/ipv4/route.c:2811
ip_route_output_key_hash+0x18d/0x2a0 net/ipv4/route.c:2702
__ip_route_output_key include/net/route.h:169 [inline]
ip_route_output_flow+0x2a/0x150 net/ipv4/route.c:2929
ip4_datagram_release_cb+0x89d/0xbe0 net/ipv4/datagram.c:118
release_sock+0x206/0x260 net/core/sock.c:3861
inet_shutdown+0x2b1/0x390 net/ipv4/af_inet.c:950
udp_tunnel_sock_release+0x6d/0x80 net/ipv4/udp_tunnel_core.c:197
fou_release net/ipv4/fou_core.c:562 [inline]
fou_exit_net+0x17d/0x1f0 net/ipv4/fou_core.c:1230
ops_exit_list net/core/net_namespace.c:199 [inline]
ops_undo_list+0x43d/0x8d0 net/core/net_namespace.c:252
cleanup_net+0x572/0x810 net/core/net_namespace.c:702
process_one_work kernel/workqueue.c:3314 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3397
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3478
kthread+0x389/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Fixes: 759923cf03b0 ("ipv4: fib: Convert fib_net_exit_batch() to ->exit_rtnl().")
Reported-by: syzbot+965506b59a2de0b6905c@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/6a315824.b0403584.28d0ff.0000.GAE@google.com/
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260616191359.4142661-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Merge in late fixes in preparation for the net-next PR.
Conflicts:
net/tls/tls_sw.c
406e8a651a7b ("net: skmsg: preserve sg.copy across SG transforms")
79511603a65b ("tls: remove dead sockmap (psock) handling from the SW path")
drivers/net/ethernet/microsoft/mana/mana_en.c
f8fd56977eeea ("net: mana: guard TX wq object destroy with INVALID_MANA_HANDLE check")
d07efe5a6e641 ("net: mana: Use per-queue allocation for tx_qp to reduce allocation size")
https://lore.kernel.org/ajAPXu-C_PuTgV-a@sirena.org.uk
No adjacent changes.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Currently sk_rethink_txhash() re-rolls the socket's txhash on RTO, PLB,
and spurious-retransmission events, but the cached route is reused and
the new hash is not propagated into the ECMP path selection logic. Two
changes are needed to make rehash select a different local ECMP path:
1. Add __sk_dst_reset() alongside sk_rethink_txhash() in
tcp_write_timeout(), tcp_rcv_spurious_retrans(), and
tcp_plb_check_rehash() so the cached dst is invalidated and the
next transmit triggers a fresh route lookup.
2. Set fl6->mp_hash from sk_txhash (or tcp_rsk(req)->txhash for
SYN/ACK retransmits and syncookies) in tcp_v6_connect(),
inet6_sk_rebuild_header(), inet6_csk_route_req(),
inet6_csk_route_socket(), tcp_v6_send_response(), and
cookie_v6_check() so fib6_select_path() picks a path based on the
new hash.
The mp_hash override only applies to fib_multipath_hash_policy 0 (the
default L3 policy). Its hash includes the flow label, but that is 0 by
default -- np->flow_label is unset, and auto_flowlabels only computes
the on-wire label later, per packet -- so flows to the same peer share
one local path. Keying the hash on sk_txhash makes the local path
per-connection and lets a rehash re-select it. Policies 1-3 are left
unchanged.
The mp_hash assignment is factored into a small helper,
ip6_ecmp_set_mp_hash(), shared by inet6_csk_route_req(),
inet6_csk_route_socket(), tcp_v6_connect(), inet6_sk_rebuild_header(),
tcp_v6_send_response(), and cookie_v6_check(). It applies
(txhash >> 1) ?: 1 for policy 0 (the >> 1 keeps mp_hash in the 31-bit
range; ?: 1 keeps it non-zero, since 0 would fall back to
rt6_multipath_hash()). inet6_csk_route_socket() calls it only for
sk_protocol == IPPROTO_TCP so that non-TCP callers (e.g., L2TP via
inet6_csk_xmit) fall through to rt6_multipath_hash() and retain their
existing flow-key-based ECMP behavior.
tcp_v6_send_response() also sets mp_hash from the response txhash so
that a control packet (a RST from the full socket, or an ACK from a
time-wait socket) selects the same local ECMP nexthop as the
connection's txhash rather than falling back to the flow hash. The
time-wait socket's tw_txhash is copied from sk_txhash when the
connection enters TIME_WAIT, so it reflects any rehash that occurred.
Setting mp_hash explicitly is necessary because the default ECMP hash
derives from fl6->flowlabel via np->flow_label, which is not updated
from sk_txhash (REPFLOW is off by default). ip6_make_flowlabel()
cannot help either, as it runs after the route lookup.
As a consequence, for policy 0 the local ECMP path of an IPv6 TCP
flow follows sk_txhash even when fl6->flowlabel is non-zero, e.g. a
reflected (REPFLOW) or explicitly set (IPV6_FLOWLABEL_MGR) flow
label. This is intentional: only local path selection changes, so
rehash can recover from a failed path; the on-wire flow label is
unchanged.
sk_set_txhash() is moved before ip6_dst_lookup_flow() in
tcp_v6_connect() so the initial ECMP path is selected by the same
txhash that subsequent route rebuilds will use. This avoids
unintended path changes when the cached dst is naturally invalidated
(e.g., by PMTU discovery or route changes).
The rehash sites (tcp_write_timeout(), tcp_plb_check_rehash(), and
tcp_rcv_spurious_retrans()) call __sk_rethink_txhash_reset_dst(),
which re-rolls the txhash and, when it changed, drops the cached dst
so the next transmit re-runs route selection. The dst reset is
guarded by sk->sk_family == AF_INET6 since IPv4 ECMP does not
currently use sk_txhash for path selection. For IPv4-mapped IPv6
sockets this produces a redundant dst reset on a cold path
(RTO/PLB); the subsequent IPv4 route lookup returns the same result.
The helper is deliberately separate from sk_rethink_txhash() itself:
dst_negative_advice() calls sk_rethink_txhash() before its own dst op,
so resetting the dst inside sk_rethink_txhash() would skip that op
(e.g. rt6_remove_exception_rt()).
For syncookies, cookie_init_sequence() computes the cookie value
before route_req() and sets txhash so the SYN-ACK selects the same
ECMP path that cookie_v6_check() will use when the full socket is
created. cookie_tcp_reqsk_init() derives txhash from the cookie so
the full socket's ECMP path matches the SYN-ACK. Both the SYN-ACK
assignment in tcp_conn_request() and the full-socket assignment in
cookie_tcp_reqsk_init() set txhash from the cookie for IPv4 and IPv6
alike. On IPv6 this drives ECMP path selection; on IPv4, which does
not use sk_txhash for ECMP, it only affects TX-queue selection. That
selection scales the hash by its high bits (reciprocal_scale()), which
are uniform in the keyed secure_tcp_syn_cookie() output -- the MSS index
only perturbs the low bits -- so the queue distribution matches
net_tx_rndhash().
cookie_init_sequence() is split from the former version that also
called tcp_synq_overflow() and incremented SYNCOOKIESSENT; those
side effects are now in cookie_record_sent(), called after
route_req() succeeds so they are not bumped when route_req() fails.
cookie_record_sent() is guarded by CONFIG_SYN_COOKIES to
match the guard on tcp_synq_overflow(). route_req() receives 0 as
tw_isn for the syncookie path so that tcp_v6_init_req() still saves
ireq->pktopts for REPFLOW flowlabel reflection and IPv6 cmsg
options. The ecn_ok clear for syncookies without timestamps stays
after tcp_ecn_create_request() so it takes precedence.
Signed-off-by: Neil Spring <ntspring@meta.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260615042158.1600746-2-ntspring@meta.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next
Pablo Neira Ayuso says:
====================
Netfilter/IPVS updates for net-next
The following patchset contains Netfilter/IPVS updates for net-next.
More specifically, this contains conncount rework to address AI related
reports, assorted Netfiter updates and two small incremental updates on
IPVS:
1) Replace old obsolete workqueues (system_wq, system_unbound_wq)
in IPVS, from Marco Crivellari.
2) Replace WARN_ON{_ONCE} by DEBUG_NET_WARN_ON_ONCE in nf_tables.
In the recent years, reporters say that the use of WARN_ON{_ONCE}
in conjunction with panic_on_warn=1 results in DoS. Let's replace
it by DEBUG_NET_WARN_ON_ONCE so this is only exercised by test
infrastructure and fuzzers, while also providing context to AI
agents. From Fernando F. Mancera.
Five patches from Florian Westphal to address AI reports in the conncount
infrastructures:
3) Fix missing rcu read lock section when calling
__ovs_ct_limit_get_zone_limit().
4) Add a dedicate lock per rbtree tree, this increases memory
usage but it should improve scalability.
5) Add a helper function to find the rbtree node, no functional
changes are intented.
6) Add sequence counter to detect concurrent tree modifications
and retry lookups.
7) Add locks to GC conncount walk and address other nitpicks.
Then, several assorted updates:
8) Defensive Tree-wide addition of NULL checks for ct extensions.
9) Bail out if flowtable bypass cannot be fully set up from the
flow offload expression, instead of lazy building a likely
incomplete one.
10) Fix documentation for the new conn_max sysctl toggle in IPVS.
11) Add nf_dev_xmit_recursion*() helpers and use them, to address
recent AI reports.
* tag 'nf-next-26-06-14' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
netfilter: nf_dup_netdev: add nf_dev_xmit_recursion*() helpers and use them
ipvs: fix doc syntax for conn_max sysctl
netfilter: flowtable: bail out if forward path cannot be discovered
netfilter: conntrack: check NULL when retrieving ct extension
netfilter: nf_conncount: gc and rcu fixes
netfilter: nf_conncount: add sequence counter to detect tree modifications
netfilter: nf_conncount: split count_tree_node rbtree walk into helper
netfilter: nf_conncount: use per nf_conncount_data spinlocks
netfilter: nf_conncount: callers must hold rcu read lock
netfilter: nf_tables: use DEBUG_NET_WARN_ON_ONCE in packet and control paths
ipvs: Replace use of system_unbound_wq with system_dfl_long_wq
====================
Link: https://patch.msgid.link/20260614114605.474783-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Currently, IPv4 routes are flushed in ->exit_batch() after
all devices are unregistered.
Unlike IPv6, IPv4 routes are not added from the fast path,
so we can flush routes before default_device_exit_batch().
Let's call ip_fib_net_exit() from ->exit_rtnl() to save
one RTNL locking dance.
ip_fib_net_exit() must use list_del_rcu() for fib_table
for the fast path on dying dev.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260612063225.455191-6-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
We will call ip_fib_net_exit() from ->exit_rtnl().
All fib_table will be destroyed before devices are unregistered.
During device unregistration, inetdev_destroy() could call
fib_del_ifaddr(), which calls fib_magic(RTM_DELROUTE).
fib_magic() calls fib_new_table(), but we do not want to create
a new table after ip_fib_net_exit() destroys all tables.
As a prep, let's add check_net() before fib_trie_table() in
fib_new_table().
fib_trie_table() is also called from fib_trie_unmerge(), but
fib_get_table() fails first in fib_unmerge(), so the same
problem does not occur there.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260612063225.455191-5-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
We will call ip_fib_net_exit() from ->exit_rtnl().
However, some paths will still access net->ipv4.fib_table_hash
after ->exit_rtnl().
For example, fib_flush() is called from fib_disable_ip() for
NETDEV_UNREGISTER.
Let's move kfree(net->ipv4.fib_table_hash) and fib4_notifier_exit()
from ip_fib_net_exit() to its caller.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260612063225.455191-4-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
We will call ip_fib_net_exit() from ->exit_rtnl().
Since the exit callbacks are called in the following order,
1. ->pre_exit()
~~~ synchronize_rcu() ~~~
2. ->exit_rtnl() : ip_fib_net_exit()
3. ->exit() : fib_proc_exit() / nl_fib_lookup_exit()
4. ->exit_batch() : fib4_semantics_exit()
the reverse order of fib_net_init() would get messed up.
Let's move fib_proc_exit() and nl_fib_lookup_exit() to ->pre_exit().
This is fine because procfs/netlink access from userspace cannot
occur at this point and synchronize_rcu() is not needed.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260612063225.455191-3-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Even when fib_table_flush() is called with flush_all true, it does
not flush all fib_info due to this condition:
!(fi->fib_flags & RTNH_F_DEAD) && !fib_props[fa->fa_type].error)
This creates an implicit ordering between default_device_exit_batch()
and fib_net_exit_batch().
fib_table_flush(flush_all=true) must be called after all devices
are NETDEV_UNREGISTERed, which is after nexthop_flush_dev() marks
RTNH_F_DEAD.
This would cause memory leak if the order were reversed.
fib_table_flush() does not skip non-dead error routes when flush_all
is true:
!flush_all &&
!(fi->fib_flags & RTNH_F_DEAD) && fib_props[fa->fa_type].error
Let's merge the two conditions not to skip all non-dead fib_info
during netns dismantle.
Note that we could further apply !flush_all to the basic table
id check and the rtmsg_fib() call in the loop.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260612063225.455191-2-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
syzbot reported use-after-free of struct sk_msg in sk_msg_recvmsg(). [0]
sk_msg_recvmsg() peeks sk_msg from psock->ingress_msg under a lock,
but its processing is lockless.
Thus, sk_msg_recvmsg() must be serialised by callers, otherwise
multiple threads could touch the same sk_msg.
For example, TCP uses lock_sock(), and AF_UNIX uses unix_sk(sk)->iolock.
Initially, udp_bpf_recvmsg() had used lock_sock(), but the cited
commit removed it.
Let's serialise sk_msg_recvmsg() with lock_sock() in udp_bpf_recvmsg().
Note that holding spin_lock_bh(&sk->sk_receive_queue.lock) is not
an option due to copy_page_to_iter() in sk_msg_recvmsg().
[0]:
BUG: KASAN: slab-use-after-free in sk_msg_recvmsg+0xb54/0xc30 net/core/skmsg.c:428
Read of size 4 at addr ffff88814cdcf000 by task syz.0.24/6020
CPU: 1 UID: 0 PID: 6020 Comm: syz.0.24 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xba/0x230 mm/kasan/report.c:482
kasan_report+0x117/0x150 mm/kasan/report.c:595
sk_msg_recvmsg+0xb54/0xc30 net/core/skmsg.c:428
udp_bpf_recvmsg+0x4bd/0xe00 net/ipv4/udp_bpf.c:84
inet_recvmsg+0x260/0x270 net/ipv4/af_inet.c:891
sock_recvmsg_nosec net/socket.c:1078 [inline]
sock_recvmsg+0x1a8/0x270 net/socket.c:1100
____sys_recvmsg+0x1e6/0x4a0 net/socket.c:2812
___sys_recvmsg+0x215/0x590 net/socket.c:2854
do_recvmmsg+0x334/0x800 net/socket.c:2949
__sys_recvmmsg net/socket.c:3023 [inline]
__do_sys_recvmmsg net/socket.c:3046 [inline]
__se_sys_recvmmsg net/socket.c:3039 [inline]
__x64_sys_recvmmsg+0x198/0x250 net/socket.c:3039
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb319f9aeb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb31ad97028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fb31a216090 RCX: 00007fb319f9aeb9
RDX: 0000000000000001 RSI: 0000200000000400 RDI: 0000000000000004
RBP: 00007fb31a008c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000040000021 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb31a216128 R14: 00007fb31a216090 R15: 00007ffe21dd0a98
</TASK>
Allocated by task 6019:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_noprof+0x3d1/0x6e0 mm/slub.c:5780
kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
alloc_sk_msg net/core/skmsg.c:510 [inline]
sk_psock_skb_ingress_self+0x60/0x350 net/core/skmsg.c:612
sk_psock_verdict_apply net/core/skmsg.c:1038 [inline]
sk_psock_verdict_recv+0x7d9/0x8d0 net/core/skmsg.c:1236
udp_read_skb+0x73e/0x7e0 net/ipv4/udp.c:2045
sk_psock_verdict_data_ready+0x12d/0x550 net/core/skmsg.c:1257
__udp_enqueue_schedule_skb+0xc54/0x10b0 net/ipv4/udp.c:1789
__udp_queue_rcv_skb net/ipv4/udp.c:2346 [inline]
udp_queue_rcv_one_skb+0xac5/0x19c0 net/ipv4/udp.c:2475
__udp4_lib_mcast_deliver+0xc06/0xcf0 net/ipv4/udp.c:2585
__udp4_lib_rcv+0x10f6/0x2620 net/ipv4/udp.c:2724
ip_protocol_deliver_rcu+0x282/0x440 net/ipv4/ip_input.c:207
ip_local_deliver_finish+0x3bb/0x6f0 net/ipv4/ip_input.c:241
NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
dst_input include/net/dst.h:474 [inline]
ip_sublist_rcv_finish+0x221/0x2a0 net/ipv4/ip_input.c:584
ip_list_rcv_finish net/ipv4/ip_input.c:628 [inline]
ip_sublist_rcv+0x5c6/0xa70 net/ipv4/ip_input.c:644
ip_list_rcv+0x3f1/0x450 net/ipv4/ip_input.c:678
__netif_receive_skb_list_ptype net/core/dev.c:6195 [inline]
__netif_receive_skb_list_core+0x7e5/0x810 net/core/dev.c:6242
__netif_receive_skb_list net/core/dev.c:6294 [inline]
netif_receive_skb_list_internal+0x995/0xcf0 net/core/dev.c:6385
netif_receive_skb_list+0x54/0x410 net/core/dev.c:6437
xdp_recv_frames net/bpf/test_run.c:269 [inline]
xdp_test_run_batch net/bpf/test_run.c:350 [inline]
bpf_test_run_xdp_live+0x1946/0x1cf0 net/bpf/test_run.c:379
bpf_prog_test_run_xdp+0x81c/0x1160 net/bpf/test_run.c:1396
bpf_prog_test_run+0x2c7/0x340 kernel/bpf/syscall.c:4703
__sys_bpf+0x5cb/0x920 kernel/bpf/syscall.c:6182
__do_sys_bpf kernel/bpf/syscall.c:6274 [inline]
__se_sys_bpf kernel/bpf/syscall.c:6272 [inline]
__x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6272
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 6021:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2540 [inline]
slab_free mm/slub.c:6674 [inline]
kfree+0x1be/0x650 mm/slub.c:6882
kfree_sk_msg include/linux/skmsg.h:385 [inline]
sk_msg_recvmsg+0xaa8/0xc30 net/core/skmsg.c:483
udp_bpf_recvmsg+0x4bd/0xe00 net/ipv4/udp_bpf.c:84
inet_recvmsg+0x260/0x270 net/ipv4/af_inet.c:891
sock_recvmsg_nosec net/socket.c:1078 [inline]
sock_recvmsg+0x1a8/0x270 net/socket.c:1100
____sys_recvmsg+0x1e6/0x4a0 net/socket.c:2812
___sys_recvmsg+0x215/0x590 net/socket.c:2854
do_recvmmsg+0x334/0x800 net/socket.c:2949
__sys_recvmmsg net/socket.c:3023 [inline]
__do_sys_recvmmsg net/socket.c:3046 [inline]
__se_sys_recvmmsg net/socket.c:3039 [inline]
__x64_sys_recvmmsg+0x198/0x250 net/socket.c:3039
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Fixes: 9f2470fbc4cb ("skmsg: Improve udp_bpf_recvmsg() accuracy")
Reported-by: syzbot+9307c991a6d07ce6e6d8@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/69922ac9.a70a0220.2c38d7.00e0.GAE@google.com/
Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Link: https://lore.kernel.org/r/20260615021959.140010-5-jiayuan.chen@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
nf_ct_ext_find() might return NULL if ct extension is not found.
Add also the null checks to:
- nfct_help()
- nfct_help_data()
- nfct_seqadj()
- nfct_nat()
This is defensive, for safety reasons.
nf_ct_ext_find() used to return NULL if the extension is stale for
unconfirmed conntracks if the genid validation fails.
Skip NULL check in nf_nat_inet_fn() given this is valid to be NULL
for non-initialized ct nat extensions.
While at it, fetch ct helper area in nf_ct_expect_related_report() only
once and pass it on to other ancilliary functions. Replace WARN_ON()
by WARN_ON_ONCE() in nf_ct_unlink_expect_report().
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
|
|
When IPv4 device configuration parameters are updated via netlink, the
kernel currently only updates the value. This bypasses several
post-modification actions that occur when these same parameters are
updated via sysctl, such as flushing the routing cache or emitting
RTM_NEWNETCONF notifications.
This patch addresses the inconsistency by calling the
devinet_conf_post_set() helper inside inet_set_link_af(). If a flush is
required, we defer it until the netlink attribute parsing loop
completes.
This ensures consistent behavior and side-effects for devconf changes,
regardless of whether they are initiated via sysctl or netlink.
Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Link: https://patch.msgid.link/20260609204520.4670-2-fmancera@suse.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
The logic for handling IPv4 devconf sysctls is scattered. Notification
and cache flushes are managed in devinet_conf_proc(), while a separate
ipv4_doint_and_flush() function and DEVINET_SYSCTL_FLUSHING_ENTRY macro
is used for properties that solely require a cache flush.
This patch refactors the sysctl handling by introducing a centralized
helper, devinet_conf_post_set(). This new function evaluates the changed
attribute and handles all necessary operations like triggering netlink
notifications. It returns a boolean indicating whether a routing cache
flush is required.
Note that the boolean is necessary as this function will be re-used for
netlink IPv4 devconf handling where the cache flushing must wait until
all the attributes have been processed.
Finally, this is introducing a small change in behavior for
IPV4_DEVCONF_ROUTE_LOCALNET. As commit d0daebc3d622 ("ipv4: Add
interface option to enable routing of 127.0.0.0/8") intended, the cache
flush should only be performed when ROUTE_LOCALNET changes from 1 to 0.
Unfortunately, this was not true because while implementing it the
DEVINET_SYSCTL_FLUSHING_ENTRY was used for the attribute, making the
code related to it on devinet_conf_proc() dead.
IPV4_DEVCONF_FORWARDING is still being handled separately as it requires
more operations.
Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Link: https://patch.msgid.link/20260609204520.4670-1-fmancera@suse.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Commit 0e24d17bd966 ("tcp: implement RFC 7323 window retraction
receiver requirements") removed the special FIN case that
was added in commit 1e3bb184e941 ("tcp: re-enable acceptance of
FIN packets when RWIN is 0").
If a peer sends a segment containing data and a FIN flag before
it learns about our window retraction and has a buggy TCP stack,
it might place the FIN one byte beyond what it thinks is the
right edge of the window (i.e., max_window_edge + 1).
The data portion (end_seq - th->fin) will end exactly at max_window_edge.
In this case, we will drop the packet if our receive queue is not empty,
even though the data was sent within the window we previously allowed.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Simon Baatz <gmbnomis@gmail.com>
Link: https://patch.msgid.link/20260608151452.706822-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next
Steffen Klassert says:
====================
pull request (net-next): ipsec-next 2026-06-12
1) Replace the open-coded manual cleanup in xfrm_add_policy() error
path with xfrm_policy_destroy() for consistency with
xfrm_policy_construct().
From Deepanshu Kartikey.
2) Limit XFRMA_TFCPAD to a sensible maximum (max IP length, 64k) since
u32 is excessive for traffic flow confidentiality padding.
From David Ahern.
3) Add a new netlink message XFRM_MSG_MIGRATE_STATE that
allows migrating individual IPsec SAs independently of
their policies. The existing XFRM_MSG_MIGRATE is tightly coupled
to policy+SA migration, lacks SPI for unique SA identification,
and cannot express reqid changes or migrate Transport mode
selectors. The new interface identifies the SA via SPI and mark,
supports reqid changes, address family changes, encap removal,
and uses an atomic create+install flow under x->lock to prevent
SN/IV reuse during AEAD SA migration.
From Antony Antony.
* tag 'ipsec-next-2026-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next:
xfrm: add documentation for XFRM_MSG_MIGRATE_STATE
xfrm: restrict netlink attributes for XFRM_MSG_MIGRATE_STATE
xfrm: add XFRM_MSG_MIGRATE_STATE for single SA migration
xfrm: make xfrm_dev_state_add xuo parameter const
xfrm: extract address family and selector validation helpers
xfrm: refactor XFRMA_MTIMER_THRESH validation into a helper
xfrm: move encap and xuo into struct xfrm_migrate
xfrm: add error messages to state migration
xfrm: add state synchronization after migration
xfrm: check family before comparing addresses in migrate
xfrm: split xfrm_state_migrate into create and install functions
xfrm: rename reqid in xfrm_migrate
xfrm: fix NAT-related field inheritance in SA migration
xfrm: allow migration from UDP encapsulated to non-encapsulated ESP
xfrm: add extack to xfrm_init_state
xfrm: remove redundant assignments
xfrm: Reject excessive values for XFRMA_TFCPAD
xfrm: cleanup error path in xfrm_add_policy()
====================
Link: https://patch.msgid.link/20260612074725.1760473-1-steffen.klassert@secunet.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
chtls was using a lot of symbols that no other module requires. Remove
those EXPORT_SYMBOL()s.
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/d124db74f6f0838b652f0ee4b4530964f3cf8d49.1781165969.git.sd@queasysnail.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
ip_tunnel_xmit() runs locklessly (dev->lltx == true).
ipgre_err() and ipip_err() also run locklessly.
We need to add READ_ONCE() and WRITE_ONCE() annotations
around t->err_count and t->err_time.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260611165247.2710257-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
A child socket inherits the listener's bpf_sock_ops_cb_flags via
sk_clone_lock(). If its setup fails in tcp_v4_syn_recv_sock() /
tcp_v6_syn_recv_sock(), the child is freed through put_and_exit, where
inet_csk_prepare_forced_close() drops the socket lock and tcp_done() runs
without it.
If BPF_SOCK_OPS_STATE_CB_FLAG was inherited, tcp_done() -> tcp_set_state()
calls tcp_call_bpf(), which expects the lock and trips sock_owned_by_me():
WARNING: include/net/sock.h:1799 at tcp_set_state+0x433/0x550
RIP: 0010:tcp_set_state+0x433/0x550 include/net/sock.h:1799
Call Trace:
<IRQ>
tcp_done+0xba/0x250 net/ipv4/tcp.c:5095
tcp_v4_syn_recv_sock+0x850/0xa50 net/ipv4/tcp_ipv4.c:1787
tcp_check_req+0xf30/0x1360 net/ipv4/tcp_minisocks.c:926
tcp_v4_rcv+0x1047/0x1b50 net/ipv4/tcp_ipv4.c:2164
</IRQ>
The child is freed before it is ever established, so it should run no
sock_ops callback. Clear its cb flags in inet_csk_prepare_for_destroy_sock(),
the common point for the IPv4, IPv6 and chtls forced-close paths and for the
MPTCP ->syn_recv_sock() failure path (dispose_child), which reaches tcp_done()
on a child that was never established too.
Suggested-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Fixes: d44874910a26 ("bpf: Add BPF_SOCK_OPS_STATE_CB")
Signed-off-by: Sechang Lim <rhkrqnwk98@gmail.com>
Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260611092923.1895982-1-rhkrqnwk98@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
xfrm async resumption hold skb->dev refcnt until after transport_finish.
However, xfrm_rcv_cb may modify skb->dev to tunnel dev without taking
device reference, such as vti_rcv_cb. The subsequent async resumption
will decrement the tunnel device's reference count, which lead to uaf
of tunnel dev and refcnt leak of orig dev as below:
unregister_netdevice: waiting for vti1 to become free. Usage count = -2
Stash the original skb->dev to fix refcnt imbalance. The new skb->dev set
by xfrm_rcv_cb can race with device teardown. Extend rcu protection over
xfrm_rcv_cb and transport_finish to prevent races.
Fixes: 1c428b038400 ("xfrm: hold dev ref until after transport_finish NF_HOOK")
Reported-by: Xu Chunxiao <xuchunxiao3@huawei.com>
Signed-off-by: Dong Chenchen <dongchenchen2@huawei.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
|
|
With TCP-timestamps (padded) taking 12 bytes and ADD_ADDR IPv6 + port
taking 30 bytes, the 40-byte limit for the TCP options is reached. In
this case, it is then not possible to send the address signal.
The idea is to let MPTCP dropping the TCP-timestamps option for some
specific packets, to be able to send some specific pure ACK carrying >28
bytes of MPTCP options, like with this specific ADD_ADDR. A new
parameter is passed from tcp_established_options to the MPTCP side to
indicate if the TCP TS option is used, and if it should be dropped. The
next commit implements the part on MPTCP side, but split into two
patches to help TCP maintainers to identify the modifications on TCP
side. This feature will be controlled by a new add_addr_v6_port_drop_ts
MPTCP sysctl knob.
It is important to keep in mind that dropping the TCP timestamps option
for one packet of the connection could eventually disrupt some
middleboxes: even if it should be unlikely, they could drop the packet
or even block the connection. That's why this new feature will be
controlled by a sysctl knob.
Note that it would be technically possible to squeeze both options into
the header if the ADD_ADDR is first written, and then the TCP timestamps
without the NOPs preceding it. But this means more modifications on TCP
side, plus some middleboxes could still be disrupted by that.
In this implementation, an unused bit is used in mptcp_out_options
structure to avoid passing an address to a local variable. Reading and
setting it needs CONFIG_MPTCP, so the whole block now has this #if
condition: mptcp_established_options() is then no longer used without
CONFIG_MPTCP.
About alternatives, instead of passing a new boolean (has_ts), another
option would be to pass the whole option structure (opts), but
'struct tcp_out_options' is currently defined in tcp_output.c, and it
would need to be exported. Plus that means the removal of the TCP TS
option would be done on the MPTCP side, and not here on the TCP side.
It feels clearer to remove other TCP options from the TCP side, than
hiding that from the MPTCP side.
Yet an other alternative would be to pass the size already taken by the
other TCP options, and have a way to drop them all when needed. But this
feels better to target only the timestamps option where dropping it
should be safe, even if it is currently the only option that would be
set before MPTCP, when MPTCP is used.
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260605-net-next-mptcp-add-addr6-port-ts-v2-5-758e7ca73f4d@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
mr_table.cache_resolve_queue_len is always updated under
spin_lock_bh(&mfc_unres_lock).
Let's convert it to u32.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260609222013.1550355-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
syzbot reported use-after-free in nsim_fib4_prepare_event(). [0]
The problem is that the following functions call fib_info_hold() /
refcount_inc() while dumping fib_info under RCU, which is unsafe.
* mlxsw_sp_router_fib4_event()
* rocker_router_fib_event()
* nsim_fib4_prepare_event()
refcount_inc_not_zero() must be used, but it would be too late
there.
Let's guarantee the lifetime of fib_info in fib_leaf_notify().
Note that IPv6 does not need the corresponding change since
fib6_table_dump() holds fib6_table.tb6_lock.
[0]:
refcount_t: addition on 0; use-after-free.
WARNING: lib/refcount.c:25 at refcount_warn_saturate+0x9f/0x110 lib/refcount.c:25, CPU#0: kworker/u8:15/3420
Modules linked in:
CPU: 0 UID: 0 PID: 3420 Comm: kworker/u8:15 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: netns cleanup_net
RIP: 0010:refcount_warn_saturate+0x9f/0x110 lib/refcount.c:25
Code: eb 66 85 db 74 3e 83 fb 01 75 4c e8 1b f1 22 fd 48 8d 3d 84 cb f1 0a 67 48 0f b9 3a eb 4a e8 08 f1 22 fd 48 8d 3d 81 cb f1 0a <67> 48 0f b9 3a eb 37 e8 f5 f0 22 fd 48 8d 3d 7e cb f1 0a 67 48 0f
RSP: 0018:ffffc9000f2c7270 EFLAGS: 00010293
RAX: ffffffff84a18858 RBX: 0000000000000002 RCX: ffff888032ff9ec0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8f9353e0
RBP: 0000000000000000 R08: ffff888032ff9ec0 R09: 0000000000000005
R10: 0000000000000100 R11: 0000000000000004 R12: ffff8880570cc000
R13: dffffc0000000000 R14: ffff88802b40563c R15: ffff8880570cc000
FS: 0000000000000000(0000) GS:ffff888126173000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb1f4d5d000 CR3: 000000006072a000 CR4: 00000000003526f0
Call Trace:
<TASK>
__refcount_add include/linux/refcount.h:-1 [inline]
__refcount_inc include/linux/refcount.h:366 [inline]
refcount_inc include/linux/refcount.h:383 [inline]
fib_info_hold include/net/ip_fib.h:629 [inline]
nsim_fib4_prepare_event drivers/net/netdevsim/fib.c:930 [inline]
nsim_fib_event_schedule_work drivers/net/netdevsim/fib.c:1000 [inline]
nsim_fib_event_nb+0x1055/0x1240 drivers/net/netdevsim/fib.c:1043
call_fib_notifier+0x45/0x80 net/core/fib_notifier.c:25
call_fib_entry_notifier net/ipv4/fib_trie.c:90 [inline]
fib_leaf_notify net/ipv4/fib_trie.c:2176 [inline]
fib_table_notify net/ipv4/fib_trie.c:2194 [inline]
fib_notify+0x36b/0x5e0 net/ipv4/fib_trie.c:2217
fib_net_dump net/core/fib_notifier.c:70 [inline]
register_fib_notifier+0x184/0x360 net/core/fib_notifier.c:108
nsim_fib_create+0x85d/0x9f0 drivers/net/netdevsim/fib.c:1596
nsim_dev_reload_create drivers/net/netdevsim/dev.c:1604 [inline]
nsim_dev_reload_up+0x374/0x7c0 drivers/net/netdevsim/dev.c:1058
devlink_reload+0x501/0x8d0 net/devlink/dev.c:475
devlink_pernet_pre_exit+0x1ff/0x420 net/devlink/core.c:558
ops_pre_exit_list net/core/net_namespace.c:161 [inline]
ops_undo_list+0x187/0x940 net/core/net_namespace.c:234
cleanup_net+0x56e/0x800 net/core/net_namespace.c:702
process_one_work kernel/workqueue.c:3314 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Fixes: 0ae3eb7b4611 ("netdevsim: fib: Perform the route programming in a non-atomic context")
Fixes: c3852ef7f2f8 ("ipv4: fib: Replay events when registering FIB notifier")
Reported-by: syzbot+cb2aa2390ac024e25f5c@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/6a290011.39669fcc.33b062.00b1.GAE@google.com/
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20260610061744.2030996-2-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Cross-merge networking fixes after downstream PR (net-7.1-rc8).
Conflicts:
drivers/net/ethernet/wangxun/txgbe/txgbe_aml.c
f67aead16e85 ("net: txgbe: rework service event handling")
57d39faed4c9 ("net: txgbe: improve functions of AML 40G devices")
net/rds/info.c
512db8267b73 ("rds: mark snapshot pages dirty in rds_info_getsockopt()")
6e94eeb2a2a6 ("rds: convert to getsockopt_iter")
Adjacent changes:
include/net/sock.h
1ee90b77b727 ("net: guard timestamp cmsgs to real error queue skbs")
f0de88303d5e ("net: make is_skb_wmem() available to modules")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
The following patchset contains Netfilter fixes for net:
1) Revalidate bridge ports, add missing NULL checks to fetch the bridge
device by the port. From Florian Westphal.
2) Fix netdevice refcount leak in the error path of nft_fwd hardware
offload function, also from Florian.
3) Unregister helper expectfn callback on conntrack helper module
removal, otherwise dangling pointer remains in place,
from Weiming Shi.
4) Fix possible pointer infoleak in getsockopt() IPT_SO_GET_ENTRIES,
From Kyle Zeng.
5) Validate that device MAC header is present before nf_syslog
accesses it. From Xiang Mei.
6-8) Three patches to address a possible infoleak of stale stack
data in three nf_tables expressions, due to mismatch in the
_init() and _eval() function which is possible since 14fb07130c7d.
From Davide Ornaghi and Florian Westphal.
netfilter pull request 26-06-10
* tag 'nf-26-06-10' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
netfilter: nft_meta_bridge: fix stale stack leak via IIFHWADDR register
netfilter: nft_fib: fix stale stack leak via the OIFNAME register
netfilter: nft_exthdr: fix register tracking for F_PRESENT flag
netfilter: nf_log: validate MAC header was set before dumping it
netfilter: x_tables: avoid leaking percpu counter pointers
netfilter: nf_conntrack: destroy stale expectfn expectations on unregister
netfilter: nf_tables_offload: drop device refcount on error
netfilter: revalidate bridge ports
====================
Link: https://patch.msgid.link/20260610161629.214092-1-pablo@netfilter.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec
Steffen Klassert says:
====================
pull request (net): ipsec 2026-06-10
1) xfrm: iptfs: preserve shared-frag marker in iptfs_consume_frags()
Propagate SKBFL_SHARED_FRAG when paged fragments are moved between
skbs so ESP can decide whether in-place crypto is safe.
2) xfrm: iptfs: fix use-after-free on first_skb in __input_process_payload
Replace the unlocked read of xtfs->ra_newskb with a local flag so a
concurrent reassembly can no longer free first_skb between
spin_unlock and the post-loop check.
3) xfrm: policy: fix use-after-free on inexact bin in xfrm_policy_bysel_ctx()
Prune the inexact bin under xfrm_policy_lock so a concurrent
xfrm_hash_rebuild() can no longer free it before xfrm_policy_kill()
dereferences it.
4) xfrm: iptfs: fix ABBA deadlock in iptfs_destroy_state()
Move hrtimer_cancel() for the output and drop timers ahead of their
spinlocks, breaking the softirq/lock cycle that could deadlock
against the timer callbacks on SMP.
5) xfrm: espintcp: do not reuse an in-progress partial send
Fail a new send when espintcp_push_msgs() returns with emsg->len
still set, so a blocking caller can no longer overwrite ctx->partial
while a previous transfer still owns it.
6) esp: fix page frag reference leak on skb_to_sgvec failure
Add a flag to esp_ssg_unref() to unconditionally unref the source
scatterlist, releasing the old page references that are otherwise
leaked when the second skb_to_sgvec() in esp_output_tail() fails.
Please pull or let me know if there are problems.
ipsec-2026-06-10
* tag 'ipsec-2026-06-10' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec:
esp: fix page frag reference leak on skb_to_sgvec failure
xfrm: espintcp: do not reuse an in-progress partial send
xfrm: iptfs: fix ABBA deadlock in iptfs_destroy_state()
xfrm: policy: fix use-after-free on inexact bin in xfrm_policy_bysel_ctx()
xfrm: iptfs: fix use-after-free on first_skb in __input_process_payload
xfrm: iptfs: preserve shared-frag marker in iptfs_consume_frags()
====================
Link: https://patch.msgid.link/20260610140800.2562818-1-steffen.klassert@secunet.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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For NFT_FIB_RESULT_OIFNAME the destination register is declared with
len = IFNAMSIZ (four 32-bit registers), but on the lookup-fail,
RTN_LOCAL and oif-mismatch paths nft_fib{4,6}_eval() only writes one
register via "*dest = 0". The remaining three registers are left as
whatever was on the stack in nft_do_chain()'s struct nft_regs, and a
downstream expression that loads the register span can leak that
uninitialised kernel stack to userspace.
The NFTA_FIB_F_PRESENT existence check has the same shape: it is only
meaningful for NFT_FIB_RESULT_OIF, yet it was accepted for any result type
while the eval stores a single byte via nft_reg_store8(), leaving the rest
of the declared span stale.
Fix both:
- replace the bare "*dest = 0" in the eval with nft_fib_store_result(),
which strscpy_pad()s the whole IFNAMSIZ for OIFNAME (and is already
used on the other early-return path), and
- restrict NFTA_FIB_F_PRESENT to NFT_FIB_RESULT_OIF and declare its
destination as a single u8, so the marked span matches the one byte
the eval writes.
Fixes: f6d0cbcf09c5 ("netfilter: nf_tables: add fib expression")
Suggested-by: Florian Westphal <fw@strlen.de>
Cc: stable@vger.kernel.org
Signed-off-by: Davide Ornaghi <d.ornaghi97@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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The native and compat get-entries paths copy the fixed rule entry header
from the kernelized rule blob to userspace before overwriting the entry's
counter fields with a sanitized counter snapshot.
On SMP kernels, entry->counters.pcnt contains the percpu allocation
address used by x_tables rule counters. A caller can provide a userspace
buffer that faults during the initial fixed-header copy after pcnt has
been copied but before the later sanitized counter copy runs. The syscall
then returns -EFAULT while leaving the raw percpu pointer in userspace.
Copy only the fixed entry prefix before counters from the kernelized rule
blob, then copy the sanitized counter snapshot into the counter field.
Apply this ordering to the IPv4, IPv6, and ARP native and compat
get-entries implementations so a fault cannot expose the internal percpu
counter pointer.
Fixes: 71ae0dff02d7 ("netfilter: xtables: use percpu rule counters")
Signed-off-by: Kyle Zeng <kylebot@openai.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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NAT helpers such as nf_nat_h323 store a raw pointer to module text in
exp->expectfn (e.g. ip_nat_q931_expect). nf_ct_helper_expectfn_unregister()
only unlinks the callback descriptor and never walks the expectation table,
so an expectation pending at module removal survives with a dangling
exp->expectfn into freed module text.
When the expected connection arrives, init_conntrack() invokes
exp->expectfn(), now a stale pointer into the unloaded module. Reproduced
on a KASAN build by loading the H.323 helpers, creating a Q.931
expectation, unloading nf_nat_h323, then connecting to the expected port:
Oops: int3: 0000 [#1] SMP KASAN NOPTI
RIP: 0010:0xffffffffa06102d1
init_conntrack.isra.0 (net/netfilter/nf_conntrack_core.c:1862)
nf_conntrack_in (net/netfilter/nf_conntrack_core.c:2049)
ipv4_conntrack_local (net/netfilter/nf_conntrack_proto.c:223)
nf_hook_slow (net/netfilter/core.c:619)
__ip_local_out (net/ipv4/ip_output.c:120)
__tcp_transmit_skb (net/ipv4/tcp_output.c:1715)
tcp_connect (net/ipv4/tcp_output.c:4374)
tcp_v4_connect (net/ipv4/tcp_ipv4.c:345)
__sys_connect (net/socket.c:2167)
Modules linked in: nf_conntrack_h323 [last unloaded: nf_nat_h323]
Reaching the dangling state requires CAP_SYS_MODULE in the initial user
namespace to remove a NAT helper that still has live expectations, so this
is a robustness fix; leaving an expectation pointing at freed text is wrong
regardless.
Add nf_ct_helper_expectfn_destroy(), which walks the expectation table and
drops every expectation whose ->expectfn matches the descriptor being torn
down. Call it from each NAT helper's exit path after the existing RCU grace
period, so no expectation outlives the code it points at and no extra
synchronize_rcu() is introduced. With the fix, the same reproducer runs to
completion without the Oops.
Fixes: f587de0e2feb ("[NETFILTER]: nf_conntrack/nf_nat: add H.323 helper port")
Reported-by: Xiang Mei <xmei5@asu.edu>
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Weiming Shi <bestswngs@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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In esp_output_tail(), when esp->inplace is false, the old skb page frags
are replaced with a new page from the xfrm page_frag cache The source
scatterlist (sg) is built from the old frags before the replacement, and
esp_ssg_unref() is responsible for releasing the old page references
after the crypto operation completes
However, if the second skb_to_sgvec() call (which builds the destination
scatterlist from the new page) fails, the code jumps to error_free which
only calls kfree(tmp). The old page frag references captured in the
source scatterlist are never released:
1 sg[] is built from old frags via skb_to_sgvec() (no extra get_page)
2 nr_frags is set to 1 and frag[0] is replaced with the new page
3 Second skb_to_sgvec() fails -> goto error_free
Fix this by adding a bool parameter to esp_ssg_unref() that, when true,
unconditionally unrefs the source scatterlist frags. Since req->src is
not yet initialized by aead_request_set_crypt() at the point of the
error, the source scatterlist is obtained directly via esp_req_sg()
Existing callers pass false to preserve the original behavior
The same issue exists in both esp4 and esp6 as the code is identical
Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible")
Fixes: 03e2a30f6a27 ("esp6: Avoid skb_cow_data whenever possible")
Signed-off-by: Alessandro Schino <7991aleschino@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
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/proc/net/igmp walks the multicast list locklessly under RCU and reads
timer-related fields (im->tm_running, im->reporter, im->timer.expires)
to print the timer state of multicast memberships. Concurrently, these
fields are modified under im->lock spinlock in timer management paths
(igmp_stop_timer(), igmp_start_timer(), and igmp_timer_expire()). Fix this
intentional lockless snapshot by annotating the lockless reads with
READ_ONCE() and the updates with WRITE_ONCE().
Signed-off-by: Yuyang Huang <yuyanghuang@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260605014318.3890804-3-yuyanghuang@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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/proc/net/igmp walks the multicast list for IPv4 interfaces locklessly
under RCU and prints state->in_dev->mc_count. Concurrently, device
init/destruction and multicast join/leave paths update the count
under the RTNL lock. Fix this intentional lockless snapshot by
annotating the read with READ_ONCE() and the updates with WRITE_ONCE().
Signed-off-by: Yuyang Huang <yuyanghuang@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260605014318.3890804-2-yuyanghuang@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Commit 22e36ea9f5d7 ("inet: allow ip_valid_fib_dump_req() to
be called with RTNL or RCU") introduced the rtnl_held field in
struct fib_dump_filter to switch __dev_get_by_index() and
dev_get_by_index_rcu() depending on the caller's context.
This field served as an interim measure while we were incrementally
converting all callers of ip_valid_fib_dump_req() to RCU.
Now that all users (IPv4, IPv6, ipmr, ip6mr, and MPLS) have
been converted to RCU, the field is no longer necessary.
Let's remove it.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260604224712.3209821-8-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next
Pablo Neira Ayuso says:
====================
Netfilter/IPVS updates for net-next
The following patchset contains Netfilter/IPVS updates for net-next,
this contains updates to address sashiko reports in IPVS and Netfilter
on possible pre-existing issues. This also includes a series to add
refcount for ct helper and timeout to deal with a corner case scenario
with unconfirmed conntracks flying to nfqueue.
1) Add a conn_max sysctl to IPVS to limit the maximum number of
connections, from Julian Anastasov.
2) Use get_unaligned_be16() to access TCP MSS in nfnetlink_osf,
from Fernando Fernandez Mancera.
3) Use {READ,WRITE}_ONCE to access helper flags from nfnetlink_helper.
Several patches for the synproxy infrastructure, from Fernando
Fernandez Mancera:
4) Drop packet if TCP timestamp adjustment fails.
5) Continue parsing of TCP timestamp to deal with possible duplicates.
6) Use {get,put}_unaligned_be32() to acess the TCP timestamp.
7) Hold ct->lock to initialize nf_ct_seqadj_init().
Updates for the ct timeout infrastructure, to deal with a corner case
for unconfirmed conntracks flying to nfqueue:
8) Add a refcount to track ct timeout policy use by ct extension,
release the timeout until the last ct extension drops the refcnt
on it.
Similar update for the ct helper infrastructure:
9) Dynamic allocation of ct helpers, as a preparation for adding
refcount to track ct extension use.
10) Move destroy_sibling_or_exp() to nf_conntrack_proto_gre, so
pptp conntrack helper module removal does not make this code
unreachable via the helper->destroy callback. This is another
dependency for the new refcount coming in this series.
11) Add a refcount to track use of it from the ct extension, then
ct helper and timeout is reachable to the connection until
it goes away.
12) Remove the genid infrastructure in ct extensions. The primary
goal was to detect that a ct extension such as ct timeout and
ct helper went stale for unconfirmed conntrack, either because
object or module was removed. This deactivates all ct extensions
though for this unconfirmed conntrack.
13) Call nf_ct_gre_keymap_destroy() if this is a master conntrack
with a pptp helper only.
sashiko.dev reports one more relevant issue when unsetting the helper
via ctnetlink that I will address in a follow up patch.
Then, two more assorted updates:
14) Avoid a unlikely underflow in bridge VLAN untag, only possible
if buggy bridge VLAN filtering is buggy, remove WARN_ON_ONCE
while at it. From David Carlier.
15) Use get_unaligned_be32() in nf_conntrack_tcp to access sack
extension, from Rosen Penev.
* tag 'nf-next-26-06-07' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
netfilter: nf_conntrack: use get_unaligned_be32() in tcp_sack()
netfilter: flowtable: avoid num_encaps underflow on bridge VLAN untag
netfilter: conntrack: call nf_ct_gre_keymap_destroy() if master helper is pptp
netfilter: conntrack: revert ct extension genid infrastructure
netfilter: nf_conntrack_helper: add refcounting from datapath
netfilter: nf_conntrack_pptp: move GRE specific cleanup to GRE tracker
netfilter: nf_conntrack_helper: dynamically allocate struct nf_conntrack_helper
netfilter: cttimeout: detach dataplane timeout policy and repurpose refcount
netfilter: synproxy: protect nf_ct_seqadj_init() with conntrack lock
netfilter: synproxy: fix unaligned memory access in timestamp adjustment
netfilter: synproxy: adjust duplicate timestamp options
netfilter: synproxy: drop packets if timestamp adjustment fails
netfilter: nfnetlink_cthelper: use {READ,WRITE}_ONCE for accessing helper flags
netfilter: nfnetlink_osf: fix mss parsing on big-endian architectures
ipvs: add conn_max sysctl to limit connections
====================
Link: https://patch.msgid.link/20260607094954.48892-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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These symbols no longer need to be exported, they are only used from
vmlinux:
- inet_send_prepare
- inet_splice_eof
- inet_sk_rebuild_header
- inet_current_timestamp
- snmp_fold_field
- snmp_get_cpu_field64
- snmp_fold_field64
- fib_nh_common_release
- fib_nh_common_init
- fib_nexthop_info
- fib_add_nexthop
- ip_build_and_send_pkt
- ipv4_sk_update_pmtu
- ipv4_sk_redirect
- rt_dst_clone
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20260604173413.2782008-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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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>
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