Cross-merge networking fixes after downstream PR (net-7.1-rc8).
Conflicts:
drivers/net/ethernet/wangxun/txgbe/txgbe_aml.c
f67aead16e ("net: txgbe: rework service event handling")
57d39faed4 ("net: txgbe: improve functions of AML 40G devices")
net/rds/info.c
512db8267b ("rds: mark snapshot pages dirty in rds_info_getsockopt()")
6e94eeb2a2 ("rds: convert to getsockopt_iter")
Adjacent changes:
include/net/sock.h
1ee90b77b7 ("net: guard timestamp cmsgs to real error queue skbs")
f0de88303d ("net: make is_skb_wmem() available to modules")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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: f6d0cbcf09 ("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>
nft_exthdr_init() passes user-controlled priv->len to
nft_parse_register_store(), which marks that many bytes in the
register bitmap as initialized. However, when NFT_EXTHDR_F_PRESENT
is set, the eval paths write only 1 byte (nft_reg_store8) or
4 bytes (*dest = 0 on TCP/DCCP error path). When len > 4,
registers beyond the first are never written, retaining
uninitialized stack data from nft_regs.
Bail out if userspace requests too much data when F_PRESENT is set.
Reported-by: Ji'an Zhou <eilaimemedsnaimel@gmail.com>
Fixes: c078ca3b0c ("netfilter: nft_exthdr: Add support for existence check")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The fallback path of dump_mac_header() guards the MAC header access
only with "skb->mac_header != skb->network_header", without checking
skb_mac_header_was_set(). When the MAC header is unset, mac_header is
0xffff, so the test passes and skb_mac_header(skb) returns
skb->head + 0xffff, ~64 KiB past the buffer; the loop then reads
dev->hard_header_len bytes out of bounds into the kernel log.
This is reachable via the netdev logger: nf_log_unknown_packet() calls
dump_mac_header() unconditionally, and an skb sent through AF_PACKET
with PACKET_QDISC_BYPASS reaches the egress hook with mac_header still
unset (__dev_queue_xmit(), which would reset it, is bypassed).
Add the skb_mac_header_was_set() check the ARPHRD_ETHER path already
uses, and replace the open-coded MAC header length test with
skb_mac_header_len(). Only skbs with an unset MAC header are affected;
valid ones are dumped as before.
BUG: KASAN: slab-out-of-bounds in dump_mac_header (net/netfilter/nf_log_syslog.c:831)
Read of size 1 at addr ffff88800ea49d3f by task exploit/148
Call Trace:
kasan_report (mm/kasan/report.c:595)
dump_mac_header (net/netfilter/nf_log_syslog.c:831)
nf_log_netdev_packet (net/netfilter/nf_log_syslog.c:938 net/netfilter/nf_log_syslog.c:963)
nf_log_packet (net/netfilter/nf_log.c:260)
nft_log_eval (net/netfilter/nft_log.c:60)
nft_do_chain (net/netfilter/nf_tables_core.c:285)
nft_do_chain_netdev (net/netfilter/nft_chain_filter.c:307)
nf_hook_slow (net/netfilter/core.c:619)
nf_hook_direct_egress (net/packet/af_packet.c:257)
packet_xmit (net/packet/af_packet.c:280)
packet_sendmsg (net/packet/af_packet.c:3114)
__sys_sendto (net/socket.c:2265)
Fixes: 7eb9282cd0 ("netfilter: ipt_LOG/ip6t_LOG: add option to print decoded MAC header")
Reported-by: Weiming Shi <bestswngs@gmail.com>
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Xiang Mei <xmei5@asu.edu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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: f587de0e2f ("[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>
Reported by sashiko:
If nft_flow_action_entry_next() returns NULL, dev reference leaks.
Fixes: c6f8557758 ("netfilter: nf_tables_offload: add nft_flow_action_entry_next() and use it")
Reported-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
ebt_redirect_tg() dereferences br_port_get_rcu() return without a
NULL check, causing a kernel panic when the bridge port has been
removed between the original hook invocation and an NFQUEUE
reinject.
A mere NULL check isn't sufficient, however. As sashiko review
points out userspace can not only remove the port from the bridge,
it could also place the device in a different virtual device, e.g.
macvlan.
If this happens, we must drop the packet, there is no way for us to
reinject it into the bridge path.
Switch to _upper API, we don't need the bridge port structure.
Also, this fix keeps another bug intact:
Both nfnetlink_log and nfnetlink_queue use CONFIG_BRIDGE_NETFILTER
too aggressive, which prevents certain logging features when queueing
in bridge family: NETFILTER_FAMILY_BRIDGE can be enabled while the old
CONFIG_BRIDGE_NETFILTER cruft is off.
Fixes tag is a common ancestor, this was always broken.
Fixes: f350a0a873 ("bridge: use rx_handler_data pointer to store net_bridge_port pointer")
Reported-by: Ji'an Zhou <eilaimemedsnaimel@gmail.com>
Assisted-by: Claude:claude-sonnet-4-6
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The timestamp-only fast path dereferences the option stream as
*(__be32 *)ptr, which assumes 4-byte alignment that the TCP option
stream does not guarantee. Use get_unaligned_be32() instead, which
reads the value safely and already returns host byte order, so the
htonl() on the comparison constant can be dropped.
This matches the existing get_unaligned_be32() use later in the same
function.
Assisted-by: Claude:Opus-4.7
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The DEV_PATH_BR_VLAN_UNTAG case post-decrements info->num_encaps
inside WARN_ON_ONCE(). num_encaps is u8, so if it's already 0 the
decrement still happens and wraps it to 255. The break only leaves
the inner switch -- a later path entry can set info->indev back to
a real device, and we end up returning with num_encaps == 255.
nft_dev_forward_path() then walks info.encap[] (size 2) up to
num_encaps, which means an OOB stack read and a bogus count copied
into the route descriptor.
Should only happen on a malformed bridge path stack, hence the WARN,
but worth handling sanely. Move the decrement out of the WARN.
[ While at this, remove the WARN_ON_ONCE since this can only happen
with a buggy bridge path stack --pablo ].
Fixes: e990cef651 ("netfilter: flowtable: add bridge vlan filtering support")
Signed-off-by: David Carlier <devnexen@gmail.com>
Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
For GRE flows, validate that the ct master helper (if any) is pptp
before calling nf_ct_gre_keymap_destroy(), so the helper data area
can be accessed safely. Note that only the pptp helper provides a
.destroy callback.
Fixes: e56894356f ("netfilter: conntrack: remove l4proto destroy hook")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This infrastructure is not used anymore after moving ct timeout and
helper to use datapath refcount to track object use.
Revert commit c56716c69c ("netfilter: extensions: introduce extension
genid count") this patch disables all ct extensions (leading to NULL)
for unconfirmed conntracks, when this is only targeted at ct helper and
ct timeout. There is also codebase that dereferences the ct extension
without checking for NULL which could lead to crash.
Fixes: c56716c69c ("netfilter: extensions: introduce extension genid count")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
64bit byteorder conversion is broken when several registers need to be
converted because the source register array advances in steps for 4 bytes
instead of 8:
for (i = ...
src64 = nft_reg_load64(&src[i]);
~~~~~ u32 *src
nft_reg_store64(&dst64[i],
Remove the multi-register support, it has other issues as well:
Pablo points out that commit
caf3ef7468 ("netfilter: nf_tables: prevent OOB access in nft_byteorder_eval")
alters semantics: before the loop operated on registers, i.e.
for ( ... )
dst32[i] = htons((u16)src32[i])
.. but after the patch it will operate on bytes, which makes this
useless to convert e.g. concatenations, which store each compound
in its own register.
Multi-convert of u32 has one theoretical application:
ct mark . meta mark . tcp dport @intervalset
Because ct mark and meta mark are host byte order, use with
intervals has to convert the byteorder for ct/meta mark value
to network byte order (bigendian).
nftables emits this:
[ meta load mark => reg 1 ]
[ byteorder reg 1 = hton(reg 1, 4, 4) ]
[ ct load mark => reg 9 ]
[ byteorder reg 9 = hton(reg 9, 4, 4) ]
...
I.e. two separate calls. Theoretically it could be changed to do:
[ meta load mark => reg 1 ]
[ ct load mark => reg 9 ]
[ byteorder reg 1 = htonl(reg 1, 4, 8) ]
...
But then all it would take to change the set to
meta mark . tcp dport . ct mark
... and we'd be back to two "byteorder" calls. IOW, support to
convert a range of registers is both dysfunctional and dubious.
Simplify this: remove the feature.
Pablo Neira Ayuso points out that nftables before 1.1.0 can generate
incorrect byteorder conversions, see 9fe58952c45a,
"evaluate: skip byteorder conversion for selector smaller than 2 bytes"
in nftables.git). Affected rulesets fail to load with this change and
old userspace due to 'len != size' check.
Fixes: c301f0981f ("netfilter: nf_tables: fix pointer math issue in nft_byteorder_eval()")
Cc: <stable+noautosel@kernel.org> # may break rule load with old nftables versions
Reported-by: Michal Kubecek <mkubecek@suse.cz>
Link: https://lore.kernel.org/netfilter-devel/20240206104336.ctigqpkunom2ufmn@lion.mk-sys.cz/
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
I noticed this issue while looking at a historic syzbot report [1].
A rule like the one below is enough to trigger the bug:
table ip t {
chain pre {
type filter hook prerouting priority raw;
ct zone set 1
ct original saddr 1.2.3.4 accept
}
}
The first expression attaches a per-cpu template ct via
nft_ct_set_zone_eval() (nf_ct_tmpl_alloc -> kzalloc, tuple is all
zero, nf_ct_l3num(ct) == 0). The next expression then calls
nft_ct_get_eval() on the same skb, treats the template as a real ct
and hits the 16-byte memcpy path. With dreg at NFT_REG32_15 this
overflows past struct nft_regs on the kernel stack; with smaller
dreg values it silently clobbers adjacent registers.
Reject template ct at the eval entry and in nft_ct_get_fast_eval(),
mirroring the check nft_ct_set_eval() already has. Additionally,
bound the address copy in NFT_CT_SRC / NFT_CT_DST by priv->len
instead of by nf_ct_l3num(ct): nf_ct_get_tuple() zeroes the tuple
before pkt_to_tuple() fills in only the protocol-relevant leading
bytes, so the trailing bytes of tuple->{src,dst}.u3.all are
well-defined zero. priv->len is validated at rule load, so the
copy size is now bounded by the destination register rather than
by an untrusted field on the conntrack.
[1]: https://syzkaller.appspot.com/bug?id=389cf09cb72926114fce90dc85a2c3231dcb647c
Fixes: 45d9bcda21 ("netfilter: nf_tables: validate len in nft_validate_data_load()")
Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nft_tunnel_obj_destroy() calls metadata_dst_free() which directly
kfree()s the metadata_dst, ignoring the dst_entry refcount. Packets
that took a reference via dst_hold() in nft_tunnel_obj_eval() and
are still queued (e.g. in a netem qdisc) are left with a dangling
pointer. When these packets are eventually dequeued, dst_release()
operates on freed memory.
Replace metadata_dst_free() with dst_release() so the metadata_dst
is freed only after all references are dropped. The dst subsystem
already handles metadata_dst cleanup in dst_destroy() when
DST_METADATA is set.
Fixes: af308b94a2 ("netfilter: nf_tables: add tunnel support")
Cc: stable@vger.kernel.org
Signed-off-by: Tristan Madani <tristan@talencesecurity.com>
Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When parsing fails after we've matched the command string we
should bail out instead of trying to match a different command.
This helper should be deprecated, given prevalence of TLS I doubt it has
any relevance in 2026.
Fixes: 869f37d8e4 ("[NETFILTER]: nf_conntrack/nf_nat: add IRC helper port")
Closes: https://sashiko.dev/#/patchset/20260525182924.28456-1-fw%40strlen.de
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
As the synproxy infrastructure register netfilter hooks on-demand when a
user adds the first iptables target or nftables expression, if done
concurrently they can race each other.
Introduce a mutex to serialize the refcount control blocks access from
both frontends. While a per namespace mutex might be more efficient, it
is not needed for target/expression like SYNPROXY.
Fixes: ad49d86e07 ("netfilter: nf_tables: Add synproxy support")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
ip_vs_edit_service() while unbinding the old scheduler clears
the svc->scheduler ptr after the scheduler module initiates
RCU callbacks. This can cause packets to use the old
scheduler at the time when svc->sched_data is already freed
after RCU grace period.
Fix it by clearing the ptr early in ip_vs_unbind_scheduler(),
before the done_service method schedules any RCU callbacks.
Also, if the new scheduler fails to initialize when replacing
the old scheduler, try to restore the old scheduler while still
returning the error code.
Link: https://sashiko.dev/#/patchset/20260519015506.634185-1-rosenp%40gmail.com
Fixes: 05f00505a8 ("ipvs: fix crash if scheduler is changed")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
With PREEMPT_RCU this triggers a splat because smp_processor_id() can be
preempted while inside a RCU critical section. If xt_NFQUEUE target is
invoked via nft_compat_eval() path, we are inside a RCU critical
section.
Just use the raw version instead.
Fixes: 0ca743a559 ("netfilter: nf_tables: add compatibility layer for x_tables")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
get_port and try_number() parse comma-separated decimal values from FTP PORT
and EPRT commands into a u_int32_t array, but does not validate that each
value fits in a single octet. RFC 959 specifies that PORT parameters
are decimal integers in the range 0-255, representing the four octets
of an IP address followed by two octets encoding the port number.
Values exceeding 255 are silently accepted. In try_rfc959(), the raw
u32 values are combined via shift-and-OR to form the IP and port:
cmd->u3.ip = htonl((array[0] << 24) | (array[1] << 16) |
(array[2] << 8) | array[3]);
cmd->u.tcp.port = htons((array[4] << 8) | array[5]);
When array elements exceed 255, bits from one field bleed into adjacent
fields after shifting, producing IP addresses and port numbers that
differ from what the text representation suggests. For example,
"PORT 10,0,1,2,256,22" yields port (256<<8)|22 = 65558, truncated to
u16 = 22. This mismatch between the textual and computed values can
confuse network monitoring tools that parse FTP commands independently.
Ignore the command by returning 0 (no match) when any accumulated
value exceeds 255 so that no expectation is created.
Signed-off-by: Giuseppe Caruso <giuseppecaruso0990@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
The avx2 lookup routines get the next map index to process passes as a
function argument, but this isn't obvious because it's hidden in the
lookup macro.
Additionally, a recent LLM review pointed out following "bug":
-------------------------------------------------------------
> b = nft_pipapo_avx2_refill(i_ul, &map[i_ul], fill, f->mt, last);
> if (last)
> - return b;
> + ret = b;
>
> if (unlikely(ret == -1))
> ret = b / XSAVE_YMM_SIZE;
Does this change introduce a logic error when last=true and no match is
found? [..]
Should this be changed to an else-if structure instead?
-------------------------------------------------------------
LLM sees a control-flow change, but there is none:
All call sites invoke nft_pipapo_avx2_refill() only when at least one
bit in the map is set, i.e. nft_pipapo_avx2_refill() never returns -1.
Add a runtime debug check that fires if we'd return -1 as additional
documentation and also make the suggested change, code might be easier
to understand this way.
In commit 17a20e09f0 ("netfilter: nft_set: remove one argument from
lookup and update functions") I incorrectly moved the "ret" scope into
the loop.
This has no effect on the correctness, but it can (depending on map sizes)
cause a redundant repeat of an earlier processing step.
Restore the intended 'pass map index' instead of always-0. Note that I
did not see any change in performance numbers, but Stefano correctly
points out that the existing perf test likely lack a sparse intermediate
bitmap (between fields) with a lot of leading zeroes.
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
parse_dcc() treats data_end as an inclusive end pointer, but its only
caller passes data_limit = ib_ptr + datalen, which points one past the
last valid byte.
The newline search loop iterates while tmp <= data_end, so when no
newline is present, *tmp is read at tmp == data_end, one byte beyond
the region filled by skb_header_pointer().
irc_buffer is kmalloc'd as MAX_SEARCH_SIZE + 1 bytes and datalen is
capped at MAX_SEARCH_SIZE, so the stray read does not fault. The byte
is uninitialized or stale; if it contains an ASCII digit, simple_strtoul
will consume it and produce a wrong DCC IP or port in the conntrack
expectation. The extra allocation byte is also a fragile guard: if the
cap or allocation size changes, this becomes a real out-of-bounds read.
Change the loop and its post-loop check to use strict less-than,
consistent with the caller's exclusive-end convention. Update the
function comment accordingly.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Muhammad Bilal <meatuni001@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
When a userspace conntrack helper with multiple expectation classes is
updated via nfnetlink, every class ends up with the first class's
max_expected and timeout values.
nfnl_cthelper_update_policy_all() validates each new policy into the
corresponding slot of the temporary new_policy array, but the second
loop that commits the values into the live helper dereferences
new_policy as a pointer instead of indexing it, so every iteration
reads new_policy[0] regardless of i. An update that changes per-class
values is silently collapsed onto class 0's values with no error
returned to userspace.
Index the temporary array by i in the commit loop so each class gets
its own validated values.
Fixes: 2c42225755 ("netfilter: nfnl_cthelper: fix runtime expectation policy updates")
Cc: stable@vger.kernel.org
Signed-off-by: David Carlier <devnexen@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
net/netfilter/nft_set_rbtree.c:399 __nft_rbtree_insert()
warn: 'removed_end' is not an error pointer
Since commit : 087388278e ("netfilter: nf_tables: nft_set_rbtree: fix
spurious insertion failure") __nft_rbtree_insert() can no longer fail
and this condition is always false. Remove it.
Reported-by: Dan Carpenter <error27@gmail.com>
Closes: https://lore.kernel.org/netfilter-devel/adjSaolTji0mPgqx@stanley.mountain/
Signed-off-by: Florian Westphal <fw@strlen.de>
Commit 02a3231b6d ("netfilter: nf_conntrack_expect: store netns and zone in expectation")
introduced exp->net so RCU-only expectation paths no longer need to
dereference exp->master for netns lookups.
Commit 3db5647984 ("netfilter: nf_conntrack_expect: skip expectations in other netns via proc")
updated the proc path accordingly, but ctnetlink_exp_dump_table() still
compares against nf_ct_net(exp->master).
Use nf_ct_exp_net(exp) here as well so the netlink dump path matches
the rest of the March 2026 expectation netns/RCU cleanup.
Fixes: 02a3231b6d ("netfilter: nf_conntrack_expect: store netns and zone in expectation")
Cc: stable@vger.kernel.org
Signed-off-by: Pratham Gupta <pratham36gupta@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
As-is, different netns will use same slots if the key is the same.
OVS uses this infrastructure to limit conntrack counts per zones.
Those can easily overlap. Make them hash to different slots internally.
Signed-off-by: Florian Westphal <fw@strlen.de>
Netfilter has its own netlink multiplexer, initially only a few
subsystem were using it, most notably conntrack, queue and log,
later in time nf_tables. These days it is the control plane of
preference.
Just remove modular support for this, allow it built-in only.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Similar to a few other subsystems: add a new config toggle to
enable netfilter gcov profiling in netfilter, including ebtables,
arptables and so on.
ipset and ipvs gain their own, dedicated toggles.
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
For lshift and rshift, the shift operations are performed in a loop over
32-bit words. The loop calculates the shifted value and write it to dst,
and then immediately reads from src to calculate the carry for the next
iteration. Because src and dst could point to the same memory location,
the carry is incorrectly calculated using the newly modified dst value
instead of the original src value.
Adding a temporary local variable to cache the original value before
writing to dst and using it for the carry calculation solves the
problem. In addition, partial overlap is rejected from control plane for
all kind of operations including byteorder. This was tested with the
following bytecode:
table test_table ip flags 0 use 1 handle 1
ip test_table test_chain use 3 type filter hook input prio 0 policy accept packets 0 bytes 0 flags 1
ip test_table test_chain 2
[ immediate reg 1 0x44332211 0x88776655 ]
[ bitwise reg 1 = ( reg 1 << 0x08000000 ) ]
[ cmp eq reg 1 0x66443322 0x00887766 ]
[ counter pkts 0 bytes 0 ]
ip test_table test_chain 4 3
[ immediate reg 1 0x44332211 0x88776655 ]
[ bitwise reg 1 = ( reg 1 << 0x08000000 ) ]
[ cmp eq reg 1 0x55443322 0x00887766 ]
[ counter pkts 21794 bytes 1917798 ]
Fixes: 567d746b55 ("netfilter: bitwise: add support for shifts.")
Acked-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Several parts of network stack rely on iph->ihl validation
done by network stack before PRE_ROUTING.
Disable this feature for user namespaces for now.
tcp option handling is likely safe even for LOCAL_IN, so this
this leaves tcp option mangling via nft_exthdr.c as-is.
I don't think these are the only means to alter packets, but these
appear to be relatively prominent.
This could be relaxed later. Example:
- allow userns for ingress hook.
- allow userns if base is transport header.
Also, we should revalidate or restrict generally:
- Don't allow linklayer writes to spill into network header
- restrict ipv4 and ipv6 to 'known safe' writes, e.g.
saddr/daddr/check/tos
Reported-by: Qi Tang <tpluszz77@gmail.com>
Reported-by: Tong Liu <lyutoon@gmail.com>
Tested-by: Qi Tang <tpluszz77@gmail.com>
Link: https://lore.kernel.org/netfilter-devel/20260515100411.3141-1-fw@strlen.de/
Signed-off-by: Florian Westphal <fw@strlen.de>
With PREEMPT_RCU we get splat:
BUG: using smp_processor_id() in preemptible [..]
caller is cpu_mt+0x53/0xd0 net/netfilter/xt_cpu.c:37
CPU: 1 .. Comm: syz.3.1377 #0 PREEMPT(full)
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
check_preemption_disabled+0xd3/0xe0 lib/smp_processor_id.c:47
cpu_mt+0x53/0xd0 net/netfilter/xt_cpu.c:37
[..]
Just use raw version instead.
This is similar to 14d14a5d29 ("netfilter: nft_meta: use raw_smp_processor_id()").
Fixes: 0ca743a559 ("netfilter: nf_tables: add compatibility layer for x_tables")
Reported-by: syzbot+690d3e3ffa7335ac10eb@syzkaller.appspotmail.com
Signed-off-by: Florian Westphal <fw@strlen.de>
Quoting reporter:
A race between GRE keymap insertion and destruction can corrupt the
kernel list or use a freed object. `nf_ct_gre_keymap_add()` publishes a
new keymap pointer before the embedded `list_head` is linked, while
`nf_ct_gre_keymap_destroy()` can concurrently delete and free that
same object. An unprivileged user can reach this through the PPTP
conntrack helper by racing PPTP control messages or helper teardown,
leading to KASAN-detectable list corruption/UAF in kernel context.
## Root Cause Analysis
`exp_gre()` installs GRE expectations for a PPTP control flow and then
adds two GRE keymap entries [..]
The add path publishes `ct_pptp_info->keymap[dir]` before linking the
embedded list node [..]
Concurrent teardown deletes that partially initialized object.
Make add/destroy symmetric: install both, destroy both while under lock.
Furthermore, we should refuse to publish a new mapping in case ct is going
away, else we may leak the allocation.
The "retrans" detection is strange: existing mapping is checked for key
equality with the new mapping, then for "is on the list" via list walk.
But I can't see how an existing keymap entry can be NOT on list.
Change this to only check if we're asked to map same tuple again -- if so,
skip re-install, else signal failure.
Last, add a bug trap for the keymap list; it has to be empty when namespace
is going away.
Reported-by: Leo Lin <leo@depthfirst.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
synproxy_tstamp_adjust() rewrites the TCP timestamp option in place
and then patches the TCP checksum via inet_proto_csum_replace4() on
the caller-supplied tcphdr pointer. Both ipv4_synproxy_hook() and
ipv6_synproxy_hook() obtain that pointer with skb_header_pointer()
before calling in, so it may either alias skb->head directly or
point at the caller's on-stack _tcph buffer.
Between obtaining the pointer and using it, the function calls
skb_ensure_writable(skb, optend), which on a cloned or non-linear
skb invokes pskb_expand_head() and frees the old skb->head. After
that point the cached th is stale:
caller (ipv[46]_synproxy_hook)
th = skb_header_pointer(skb, ..., &_tcph)
synproxy_tstamp_adjust(skb, protoff, th, ...)
skb_ensure_writable(skb, optend)
pskb_expand_head() /* kfree(old skb->head) */
...
inet_proto_csum_replace4(&th->check, ...)
/* writes into freed head, or
into the caller's stack copy
leaving the on-wire checksum
stale */
The option bytes are written through skb->data and are fine; only
the checksum update goes through th and so lands in the wrong
place. The result is either a write into freed slab memory or a
packet leaving with a checksum that does not match its payload.
Fix by re-deriving th from skb->data + protoff immediately after
skb_ensure_writable() succeeds, so the subsequent checksum update
targets the linear, writable header.
Fixes: 48b1de4c11 ("netfilter: add SYNPROXY core/target")
Assisted-by: kres (claude-opus-4-7)
Signed-off-by: Chris Mason <clm@meta.com>
Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
An unintended behavior in the TCP conntrack state machine allows a
connection to be forced into the CLOSE state using an RST packet with an
invalid sequence number.
Specifically, after a SYN packet is observed, an RST with an invalid SEQ
can transition the conntrack entry to TCP_CONNTRACK_CLOSE, regardless of
whether the RST corresponds to the expected reply direction. The relevant
code path assumes the RST is a response to an outgoing SYN, but does not
validate packet direction or ensure that a matching SYN was actually sent
in the opposite direction.
As a result, a crafted packet sequence consisting of a SYN followed by an
invalid-sequence RST can prematurely terminate an active NAT entry. This
makes connection teardown easier than intended.
So, tighten the state transition logic to ensure that RST-triggered
CLOSE transitions only occur when the RST is a valid response to a
previously observed SYN in the correct direction.
Cc: stable@vger.kernel.org
Fixes: 9fb9cbb108 ("[NETFILTER]: Add nf_conntrack subsystem.")
Signed-off-by: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
br_pass_frame_up() rewrites skb->dev from the ingress port to the bridge
master before queueing bridge LOCAL_IN packets. NFQUEUE only holds
references on state.in/out and bridge physdevs, so a queued bridge
packet can retain a freed bridge master in skb->dev until reinjection.
When the verdict is reinjected later, br_netif_receive_skb() re-enters
the receive path with skb->dev still pointing at the freed bridge master,
triggering a use-after-free.
Store skb->dev in the queue entry, hold a reference on it for the queue
lifetime, and use the saved device when dropping queued packets during
NETDEV_DOWN handling.
Fixes: ac28634456 ("netfilter: bridge: add nf_afinfo to enable queuing to userspace")
Cc: stable@kernel.org
Reported-by: Yuan Tan <yuantan098@gmail.com>
Reported-by: Yifan Wu <yifanwucs@gmail.com>
Reported-by: Juefei Pu <tomapufckgml@gmail.com>
Reported-by: Xin Liu <bird@lzu.edu.cn>
Signed-off-by: Haoze Xie <royenheart@gmail.com>
Signed-off-by: Ren Wei <n05ec@lzu.edu.cn>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The "pos" structure member of struct hbucket stores the first
free slot in the hash bucket of a hash type of set and there
are concurrent readers/writers. Annotate accesses properly.
Fixes: 18f84d41d3 ("netfilter: ipset: Introduce RCU locking in hash:* types")
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
