Currently, MLO support is not added for WEXT code and WEXT handlers are
prevented on MLDs. Prevent WEXT handler cfg80211_wext_siwencodeext()
also on MLD which is missed in commit 7b0a0e3c3a88 ("wifi: cfg80211: do
some rework towards MLO link APIs")
Signed-off-by: Veerendranath Jakkam <quic_vjakkam@quicinc.com>
Link: https://lore.kernel.org/r/20220730052643.1959111-3-quic_vjakkam@quicinc.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
MLO connections are not supposed to use WEP security. Reject connect
response of MLO connection if WEP security mode is used.
Signed-off-by: Veerendranath Jakkam <quic_vjakkam@quicinc.com>
Link: https://lore.kernel.org/r/20220730052643.1959111-2-quic_vjakkam@quicinc.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
We've already freed the assoc_data at this point, so need
to use another copy of the AP (MLD) address instead.
Fixes: 81151ce462e5 ("wifi: mac80211: support MLO authentication/association with one link")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Configure the correct link per the passed parameters.
Signed-off-by: Shaul Triebitz <shaul.triebitz@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The Tx queue parameters are per link, so add the link ID
from nl80211 parameters to the API.
While at it, lock the wdev when calling into the driver
so it (and we) can check the link ID appropriately.
Signed-off-by: Shaul Triebitz <shaul.triebitz@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
For an AP interface, set the link BSSID when the link
is initialized.
Signed-off-by: Shaul Triebitz <shaul.triebitz@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
When checking for channel regulatory validity, use the
AP link chandef (and not mesh's chandef).
Fixes: 7b0a0e3c3a88 ("wifi: cfg80211: do some rework towards MLO link APIs")
Signed-off-by: Shaul Triebitz <shaul.triebitz@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Based on changes in the specification the TBTT information in
the RNR can include MLD information, so update the parsing to
allow extracting the short SSID information in such a case.
Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
In ieee80211_sta_remove_link, valid_links is set to
the new_links before calling drv_change_sta_links, but
is used for the old_links.
Fixes: cb71f1d136a6 ("wifi: mac80211: add sta link addition/removal")
Signed-off-by: Shaul Triebitz <shaul.triebitz@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
If there's no link ID, then check that there are no changes to
the link, and if so accept them, unless a new link is created.
While at it, reject creating a new link without an address.
This fixes authorizing an MLD (peer) that has no link 0.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Introduce a simple helper function to replace a common pattern.
When accessing the GRO header, we fetch the pointer from frag0,
then test its validity and fetch it from the skb when necessary.
This leads to the pattern
skb_gro_header_fast -> skb_gro_header_hard -> skb_gro_header_slow
recurring many times throughout GRO code.
This patch replaces these patterns with a single inlined function
call, improving code readability.
Signed-off-by: Richard Gobert <richardbgobert@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20220823071034.GA56142@debian
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The ieee80211_lookup_ra_sta() function will sometimes set "sta" to NULL
so add this NULL check to prevent an Oops.
Fixes: 9dd1953846c7 ("wifi: nl80211/mac80211: clarify link ID in control port TX")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/YuKcTAyO94YOy0Bu@kili
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The return type is supposed to be ssize_t, which is signed long,
but "r" was declared as unsigned int. This means that on 64 bit systems
we return positive values instead of negative error codes.
Fixes: 80a3511d70e8 ("cfg80211: add debugfs HT40 allow map")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/YutvOQeJm0UjLhwU@kili
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Add missing dev_kfree_skb() in an error path in
ieee80211_tx_control_port() to avoid a memory leak.
Fixes: dd820ed6336a ("wifi: mac80211: return error from control port TX for drops")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20220818043349.4168835-1-yangyingliang@huawei.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
ieee80211_scan_rx() tries to access scan_req->flags after a
null check, but a UAF is observed when the scan is completed
and __ieee80211_scan_completed() executes, which then calls
cfg80211_scan_done() leading to the freeing of scan_req.
Since scan_req is rcu_dereference()'d, prevent the racing in
__ieee80211_scan_completed() by ensuring that from mac80211's
POV it is no longer accessed from an RCU read critical section
before we call cfg80211_scan_done().
Cc: stable@vger.kernel.org
Link: https://syzkaller.appspot.com/bug?extid=f9acff9bf08a845f225d
Reported-by: syzbot+f9acff9bf08a845f225d@syzkaller.appspotmail.com
Suggested-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Siddh Raman Pant <code@siddh.me>
Link: https://lore.kernel.org/r/20220819200340.34826-1-code@siddh.me
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The current bind hashtable (bhash) is hashed by port only.
In the socket bind path, we have to check for bind conflicts by
traversing the specified port's inet_bind_bucket while holding the
hashbucket's spinlock (see inet_csk_get_port() and
inet_csk_bind_conflict()). In instances where there are tons of
sockets hashed to the same port at different addresses, the bind
conflict check is time-intensive and can cause softirq cpu lockups,
as well as stops new tcp connections since __inet_inherit_port()
also contests for the spinlock.
This patch adds a second bind table, bhash2, that hashes by
port and sk->sk_rcv_saddr (ipv4) and sk->sk_v6_rcv_saddr (ipv6).
Searching the bhash2 table leads to significantly faster conflict
resolution and less time holding the hashbucket spinlock.
Please note a few things:
* There can be the case where the a socket's address changes after it
has been bound. There are two cases where this happens:
1) The case where there is a bind() call on INADDR_ANY (ipv4) or
IPV6_ADDR_ANY (ipv6) and then a connect() call. The kernel will
assign the socket an address when it handles the connect()
2) In inet_sk_reselect_saddr(), which is called when rebuilding the
sk header and a few pre-conditions are met (eg rerouting fails).
In these two cases, we need to update the bhash2 table by removing the
entry for the old address, and add a new entry reflecting the updated
address.
* The bhash2 table must have its own lock, even though concurrent
accesses on the same port are protected by the bhash lock. Bhash2 must
have its own lock to protect against cases where sockets on different
ports hash to different bhash hashbuckets but to the same bhash2
hashbucket.
This brings up a few stipulations:
1) When acquiring both the bhash and the bhash2 lock, the bhash2 lock
will always be acquired after the bhash lock and released before the
bhash lock is released.
2) There are no nested bhash2 hashbucket locks. A bhash2 lock is always
acquired+released before another bhash2 lock is acquired+released.
* The bhash table cannot be superseded by the bhash2 table because for
bind requests on INADDR_ANY (ipv4) or IPV6_ADDR_ANY (ipv6), every socket
bound to that port must be checked for a potential conflict. The bhash
table is the only source of port->socket associations.
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
1) Fix crash with malformed ebtables blob which do not provide all
entry points, from Florian Westphal.
2) Fix possible TCP connection clogging up with default 5-days
timeout in conntrack, from Florian.
3) Fix crash in nf_tables tproxy with unsupported chains, also from Florian.
4) Do not allow to update implicit chains.
5) Make table handle allocation per-netns to fix data race.
6) Do not truncated payload length and offset, and checksum offset.
Instead report EINVAl.
7) Enable chain stats update via static key iff no error occurs.
8) Restrict osf expression to ip, ip6 and inet families.
9) Restrict tunnel expression to netdev family.
10) Fix crash when trying to bind again an already bound chain.
11) Flowtable garbage collector might leave behind pending work to
delete entries. This patch comes with a previous preparation patch
as dependency.
12) Allow net.netfilter.nf_conntrack_frag6_high_thresh to be lowered,
from Eric Dumazet.
* git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
netfilter: nf_defrag_ipv6: allow nf_conntrack_frag6_high_thresh increases
netfilter: flowtable: fix stuck flows on cleanup due to pending work
netfilter: flowtable: add function to invoke garbage collection immediately
netfilter: nf_tables: disallow binding to already bound chain
netfilter: nft_tunnel: restrict it to netdev family
netfilter: nft_osf: restrict osf to ipv4, ipv6 and inet families
netfilter: nf_tables: do not leave chain stats enabled on error
netfilter: nft_payload: do not truncate csum_offset and csum_type
netfilter: nft_payload: report ERANGE for too long offset and length
netfilter: nf_tables: make table handle allocation per-netns friendly
netfilter: nf_tables: disallow updates of implicit chain
netfilter: nft_tproxy: restrict to prerouting hook
netfilter: conntrack: work around exceeded receive window
netfilter: ebtables: reject blobs that don't provide all entry points
====================
Link: https://lore.kernel.org/r/20220824220330.64283-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
While reading sysctl_somaxconn, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its reader.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While reading netdev_unregister_timeout_secs, it can be changed
concurrently. Thus, we need to add READ_ONCE() to its reader.
Fixes: 5aa3afe107d9 ("net: make unregister netdev warning timeout configurable")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While reading sysctl_devconf_inherit_init_net, it can be changed
concurrently. Thus, we need to add READ_ONCE() to its readers.
Fixes: 856c395cfa63 ("net: introduce a knob to control whether to inherit devconf config")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While reading netdev_budget_usecs, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its reader.
Fixes: 7acf8a1e8a28 ("Replace 2 jiffies with sysctl netdev_budget_usecs to enable softirq tuning")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While reading sysctl_max_skb_frags, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.
Fixes: 5f74f82ea34c ("net:Add sysctl_max_skb_frags")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While reading netdev_budget, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its reader.
Fixes: 51b0bdedb8e7 ("[NET]: Separate two usages of netdev_max_backlog.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While reading sysctl_net_busy_read, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its reader.
Fixes: 2d48d67fa8cd ("net: poll/select low latency socket support")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While reading sysctl_tstamp_allow_data, it can be changed
concurrently. Thus, we need to add READ_ONCE() to its reader.
Fixes: b245be1f4db1 ("net-timestamp: no-payload only sysctl")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While reading sysctl_optmem_max, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While reading netdev_tstamp_prequeue, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.
Fixes: 3b098e2d7c69 ("net: Consistent skb timestamping")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While reading netdev_max_backlog, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.
While at it, we remove the unnecessary spaces in the doc.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While reading weight_p, it can be changed concurrently. Thus, we need
to add READ_ONCE() to its reader.
Also, dev_[rt]x_weight can be read/written at the same time. So, we
need to use READ_ONCE() and WRITE_ONCE() for its access. Moreover, to
use the same weight_p while changing dev_[rt]x_weight, we add a mutex
in proc_do_dev_weight().
Fixes: 3d48b53fb2ae ("net: dev_weight: TX/RX orthogonality")
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While reading sysctl_[rw]mem_(max|default), they can be changed
concurrently. Thus, we need to add READ_ONCE() to its readers.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
skb_copy_bits() could fail, which requires a check on the return
value.
Signed-off-by: Li Zhong <floridsleeves@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tcp_md5sig_pool_populated can be read while another thread
changes its value.
The race has no consequence because allocations
are protected with tcp_md5sig_mutex.
This patch adds READ_ONCE() and WRITE_ONCE() to document
the race and silence KCSAN.
Reported-by: Abhishek Shah <abhishek.shah@columbia.edu>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Steffen Klassert says:
====================
pull request (net): ipsec 2022-08-24
1) Fix a refcount leak in __xfrm_policy_check.
From Xin Xiong.
2) Revert "xfrm: update SA curlft.use_time". This
violates RFC 2367. From Antony Antony.
3) Fix a comment on XFRMA_LASTUSED.
From Antony Antony.
4) x->lastused is not cloned in xfrm_do_migrate.
Fix from Antony Antony.
5) Serialize the calls to xfrm_probe_algs.
From Herbert Xu.
6) Fix a null pointer dereference of dst->dev on a metadata
dst in xfrm_lookup_with_ifid. From Nikolay Aleksandrov.
Please pull or let me know if there are problems.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
It is not allowed to call kfree_skb() from hardware interrupt
context or with interrupts being disabled. So add all skb to
a tmp list, then free them after spin_unlock_irqrestore() at
once.
Fixes: 66ba215cb513 ("neigh: fix possible DoS due to net iface start/stop loop")
Suggested-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Sometimes, gcc will optimize the function by spliting it to two or
more functions. In this case, kfree_skb_reason() is splited to
kfree_skb_reason and kfree_skb_reason.part.0. However, the
function/tracepoint trace_kfree_skb() in it needs the return address
of kfree_skb_reason().
This split makes the call chains becomes:
kfree_skb_reason() -> kfree_skb_reason.part.0 -> trace_kfree_skb()
which makes the return address that passed to trace_kfree_skb() be
kfree_skb().
Therefore, introduce '__fix_address', which is the combination of
'__noclone' and 'noinline', and apply it to kfree_skb_reason() to
prevent to from being splited or made inline.
(Is it better to simply apply '__noclone oninline' to kfree_skb_reason?
I'm thinking maybe other functions have the same problems)
Meanwhile, wrap 'skb_unref()' with 'unlikely()', as the compiler thinks
it is likely return true and splits kfree_skb_reason().
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, net.netfilter.nf_conntrack_frag6_high_thresh can only be lowered.
I found this issue while investigating a probable kernel issue
causing flakes in tools/testing/selftests/net/ip_defrag.sh
In particular, these sysctl changes were ignored:
ip netns exec "${NETNS}" sysctl -w net.netfilter.nf_conntrack_frag6_high_thresh=9000000 >/dev/null 2>&1
ip netns exec "${NETNS}" sysctl -w net.netfilter.nf_conntrack_frag6_low_thresh=7000000 >/dev/null 2>&1
This change is inline with commit 836196239298 ("net/ipfrag: let ip[6]frag_high_thresh
in ns be higher than in init_net")
Fixes: 8db3d41569bb ("netfilter: nf_defrag_ipv6: use net_generic infra")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
To clear the flow table on flow table free, the following sequence
normally happens in order:
1) gc_step work is stopped to disable any further stats/del requests.
2) All flow table entries are set to teardown state.
3) Run gc_step which will queue HW del work for each flow table entry.
4) Waiting for the above del work to finish (flush).
5) Run gc_step again, deleting all entries from the flow table.
6) Flow table is freed.
But if a flow table entry already has pending HW stats or HW add work
step 3 will not queue HW del work (it will be skipped), step 4 will wait
for the pending add/stats to finish, and step 5 will queue HW del work
which might execute after freeing of the flow table.
To fix the above, this patch flushes the pending work, then it sets the
teardown flag to all flows in the flowtable and it forces a garbage
collector run to queue work to remove the flows from hardware, then it
flushes this new pending work and (finally) it forces another garbage
collector run to remove the entry from the software flowtable.
Stack trace:
[47773.882335] BUG: KASAN: use-after-free in down_read+0x99/0x460
[47773.883634] Write of size 8 at addr ffff888103b45aa8 by task kworker/u20:6/543704
[47773.885634] CPU: 3 PID: 543704 Comm: kworker/u20:6 Not tainted 5.12.0-rc7+ #2
[47773.886745] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009)
[47773.888438] Workqueue: nf_ft_offload_del flow_offload_work_handler [nf_flow_table]
[47773.889727] Call Trace:
[47773.890214] dump_stack+0xbb/0x107
[47773.890818] print_address_description.constprop.0+0x18/0x140
[47773.892990] kasan_report.cold+0x7c/0xd8
[47773.894459] kasan_check_range+0x145/0x1a0
[47773.895174] down_read+0x99/0x460
[47773.899706] nf_flow_offload_tuple+0x24f/0x3c0 [nf_flow_table]
[47773.907137] flow_offload_work_handler+0x72d/0xbe0 [nf_flow_table]
[47773.913372] process_one_work+0x8ac/0x14e0
[47773.921325]
[47773.921325] Allocated by task 592159:
[47773.922031] kasan_save_stack+0x1b/0x40
[47773.922730] __kasan_kmalloc+0x7a/0x90
[47773.923411] tcf_ct_flow_table_get+0x3cb/0x1230 [act_ct]
[47773.924363] tcf_ct_init+0x71c/0x1156 [act_ct]
[47773.925207] tcf_action_init_1+0x45b/0x700
[47773.925987] tcf_action_init+0x453/0x6b0
[47773.926692] tcf_exts_validate+0x3d0/0x600
[47773.927419] fl_change+0x757/0x4a51 [cls_flower]
[47773.928227] tc_new_tfilter+0x89a/0x2070
[47773.936652]
[47773.936652] Freed by task 543704:
[47773.937303] kasan_save_stack+0x1b/0x40
[47773.938039] kasan_set_track+0x1c/0x30
[47773.938731] kasan_set_free_info+0x20/0x30
[47773.939467] __kasan_slab_free+0xe7/0x120
[47773.940194] slab_free_freelist_hook+0x86/0x190
[47773.941038] kfree+0xce/0x3a0
[47773.941644] tcf_ct_flow_table_cleanup_work
Original patch description and stack trace by Paul Blakey.
Fixes: c29f74e0df7a ("netfilter: nf_flow_table: hardware offload support")
Reported-by: Paul Blakey <paulb@nvidia.com>
Tested-by: Paul Blakey <paulb@nvidia.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Only allow to use this expression from NFPROTO_NETDEV family.
Fixes: af308b94a2a4 ("netfilter: nf_tables: add tunnel support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
As it was originally intended, restrict extension to supported families.
Fixes: b96af92d6eaf ("netfilter: nf_tables: implement Passive OS fingerprint module in nft_osf")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Error might occur later in the nf_tables_addchain() codepath, enable
static key only after transaction has been created.
Fixes: 9f08ea848117 ("netfilter: nf_tables: keep chain counters away from hot path")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Instead report ERANGE if csum_offset is too long, and EOPNOTSUPP if type
is not support.
Fixes: 7ec3f7b47b8d ("netfilter: nft_payload: add packet mangling support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Instead of offset and length are truncation to u8, report ERANGE.
Fixes: 96518518cc41 ("netfilter: add nftables")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
TPROXY is only allowed from prerouting, but nft_tproxy doesn't check this.
This fixes a crash (null dereference) when using tproxy from e.g. output.
Fixes: 4ed8eb6570a4 ("netfilter: nf_tables: Add native tproxy support")
Reported-by: Shell Chen <xierch@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
When a TCP sends more bytes than allowed by the receive window, all future
packets can be marked as invalid.
This can clog up the conntrack table because of 5-day default timeout.
Sequence of packets:
01 initiator > responder: [S], seq 171, win 5840, options [mss 1330,sackOK,TS val 63 ecr 0,nop,wscale 1]
02 responder > initiator: [S.], seq 33211, ack 172, win 65535, options [mss 1460,sackOK,TS val 010 ecr 63,nop,wscale 8]
03 initiator > responder: [.], ack 33212, win 2920, options [nop,nop,TS val 068 ecr 010], length 0
04 initiator > responder: [P.], seq 172:240, ack 33212, win 2920, options [nop,nop,TS val 279 ecr 010], length 68
Window is 5840 starting from 33212 -> 39052.
05 responder > initiator: [.], ack 240, win 256, options [nop,nop,TS val 872 ecr 279], length 0
06 responder > initiator: [.], seq 33212:34530, ack 240, win 256, options [nop,nop,TS val 892 ecr 279], length 1318
This is fine, conntrack will flag the connection as having outstanding
data (UNACKED), which lowers the conntrack timeout to 300s.
07 responder > initiator: [.], seq 34530:35848, ack 240, win 256, options [nop,nop,TS val 892 ecr 279], length 1318
08 responder > initiator: [.], seq 35848:37166, ack 240, win 256, options [nop,nop,TS val 892 ecr 279], length 1318
09 responder > initiator: [.], seq 37166:38484, ack 240, win 256, options [nop,nop,TS val 892 ecr 279], length 1318
10 responder > initiator: [.], seq 38484:39802, ack 240, win 256, options [nop,nop,TS val 892 ecr 279], length 1318
Packet 10 is already sending more than permitted, but conntrack doesn't
validate this (only seq is tested vs. maxend, not 'seq+len').
38484 is acceptable, but only up to 39052, so this packet should
not have been sent (or only 568 bytes, not 1318).
At this point, connection is still in '300s' mode.
Next packet however will get flagged:
11 responder > initiator: [P.], seq 39802:40128, ack 240, win 256, options [nop,nop,TS val 892 ecr 279], length 326
nf_ct_proto_6: SEQ is over the upper bound (over the window of the receiver) .. LEN=378 .. SEQ=39802 ACK=240 ACK PSH ..
Now, a couple of replies/acks comes in:
12 initiator > responder: [.], ack 34530, win 4368,
[.. irrelevant acks removed ]
16 initiator > responder: [.], ack 39802, win 8712, options [nop,nop,TS val 296201291 ecr 2982371892], length 0
This ack is significant -- this acks the last packet send by the
responder that conntrack considered valid.
This means that ack == td_end. This will withdraw the
'unacked data' flag, the connection moves back to the 5-day timeout
of established conntracks.
17 initiator > responder: ack 40128, win 10030, ...
This packet is also flagged as invalid.
Because conntrack only updates state based on packets that are
considered valid, packet 11 'did not exist' and that gets us:
nf_ct_proto_6: ACK is over upper bound 39803 (ACKed data not seen yet) .. SEQ=240 ACK=40128 WINDOW=10030 RES=0x00 ACK URG
Because this received and processed by the endpoints, the conntrack entry
remains in a bad state, no packets will ever be considered valid again:
30 responder > initiator: [F.], seq 40432, ack 2045, win 391, ..
31 initiator > responder: [.], ack 40433, win 11348, ..
32 initiator > responder: [F.], seq 2045, ack 40433, win 11348 ..
... all trigger 'ACK is over bound' test and we end up with
non-early-evictable 5-day default timeout.
NB: This patch triggers a bunch of checkpatch warnings because of silly
indent. I will resend the cleanup series linked below to reduce the
indent level once this change has propagated to net-next.
I could route the cleanup via nf but that causes extra backport work for
stable maintainers.
Link: https://lore.kernel.org/netfilter-devel/20220720175228.17880-1-fw@strlen.de/T/#mb1d7147d36294573cc4f81d00f9f8dadfdd06cd8
Signed-off-by: Florian Westphal <fw@strlen.de>
