<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/net, branch v5.18-rc5</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge tag 'ceph-for-5.18-rc5' of https://github.com/ceph/ceph-client</title>
<updated>2022-04-29T21:37:35+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-04-29T21:37:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=bd383b8e32f6aab08c9485b1fe86e2e932b1df69'/>
<id>bd383b8e32f6aab08c9485b1fe86e2e932b1df69</id>
<content type='text'>
Pull ceph client fixes from Ilya Dryomov:
 "A fix for a NULL dereference that turns out to be easily triggerable
  by fsync (marked for stable) and a false positive WARN and snap_rwsem
  locking fixups"

* tag 'ceph-for-5.18-rc5' of https://github.com/ceph/ceph-client:
  ceph: fix possible NULL pointer dereference for req-&gt;r_session
  ceph: remove incorrect session state check
  ceph: get snap_rwsem read lock in handle_cap_export for ceph_add_cap
  libceph: disambiguate cluster/pool full log message
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull ceph client fixes from Ilya Dryomov:
 "A fix for a NULL dereference that turns out to be easily triggerable
  by fsync (marked for stable) and a false positive WARN and snap_rwsem
  locking fixups"

* tag 'ceph-for-5.18-rc5' of https://github.com/ceph/ceph-client:
  ceph: fix possible NULL pointer dereference for req-&gt;r_session
  ceph: remove incorrect session state check
  ceph: get snap_rwsem read lock in handle_cap_export for ceph_add_cap
  libceph: disambiguate cluster/pool full log message
</pre>
</div>
</content>
</entry>
<entry>
<title>tcp: fix F-RTO may not work correctly when receiving DSACK</title>
<updated>2022-04-28T17:35:38+00:00</updated>
<author>
<name>Pengcheng Yang</name>
<email>yangpc@wangsu.com</email>
</author>
<published>2022-04-26T10:03:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d9157f6806d1499e173770df1f1b234763de5c79'/>
<id>d9157f6806d1499e173770df1f1b234763de5c79</id>
<content type='text'>
Currently DSACK is regarded as a dupack, which may cause
F-RTO to incorrectly enter "loss was real" when receiving
DSACK.

Packetdrill to demonstrate:

// Enable F-RTO and TLP
    0 `sysctl -q net.ipv4.tcp_frto=2`
    0 `sysctl -q net.ipv4.tcp_early_retrans=3`
    0 `sysctl -q net.ipv4.tcp_congestion_control=cubic`

// Establish a connection
   +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
   +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
   +0 bind(3, ..., ...) = 0
   +0 listen(3, 1) = 0

// RTT 10ms, RTO 210ms
  +.1 &lt; S 0:0(0) win 32792 &lt;mss 1000,sackOK,nop,nop,nop,wscale 7&gt;
   +0 &gt; S. 0:0(0) ack 1 &lt;...&gt;
 +.01 &lt; . 1:1(0) ack 1 win 257
   +0 accept(3, ..., ...) = 4

// Send 2 data segments
   +0 write(4, ..., 2000) = 2000
   +0 &gt; P. 1:2001(2000) ack 1

// TLP
+.022 &gt; P. 1001:2001(1000) ack 1

// Continue to send 8 data segments
   +0 write(4, ..., 10000) = 10000
   +0 &gt; P. 2001:10001(8000) ack 1

// RTO
+.188 &gt; . 1:1001(1000) ack 1

// The original data is acked and new data is sent(F-RTO step 2.b)
   +0 &lt; . 1:1(0) ack 2001 win 257
   +0 &gt; P. 10001:12001(2000) ack 1

// D-SACK caused by TLP is regarded as a dupack, this results in
// the incorrect judgment of "loss was real"(F-RTO step 3.a)
+.022 &lt; . 1:1(0) ack 2001 win 257 &lt;sack 1001:2001,nop,nop&gt;

// Never-retransmitted data(3001:4001) are acked and
// expect to switch to open state(F-RTO step 3.b)
   +0 &lt; . 1:1(0) ack 4001 win 257
+0 %{ assert tcpi_ca_state == 0, tcpi_ca_state }%

Fixes: e33099f96d99 ("tcp: implement RFC5682 F-RTO")
Signed-off-by: Pengcheng Yang &lt;yangpc@wangsu.com&gt;
Acked-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Tested-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Link: https://lore.kernel.org/r/1650967419-2150-1-git-send-email-yangpc@wangsu.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently DSACK is regarded as a dupack, which may cause
F-RTO to incorrectly enter "loss was real" when receiving
DSACK.

Packetdrill to demonstrate:

// Enable F-RTO and TLP
    0 `sysctl -q net.ipv4.tcp_frto=2`
    0 `sysctl -q net.ipv4.tcp_early_retrans=3`
    0 `sysctl -q net.ipv4.tcp_congestion_control=cubic`

// Establish a connection
   +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
   +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
   +0 bind(3, ..., ...) = 0
   +0 listen(3, 1) = 0

// RTT 10ms, RTO 210ms
  +.1 &lt; S 0:0(0) win 32792 &lt;mss 1000,sackOK,nop,nop,nop,wscale 7&gt;
   +0 &gt; S. 0:0(0) ack 1 &lt;...&gt;
 +.01 &lt; . 1:1(0) ack 1 win 257
   +0 accept(3, ..., ...) = 4

// Send 2 data segments
   +0 write(4, ..., 2000) = 2000
   +0 &gt; P. 1:2001(2000) ack 1

// TLP
+.022 &gt; P. 1001:2001(1000) ack 1

// Continue to send 8 data segments
   +0 write(4, ..., 10000) = 10000
   +0 &gt; P. 2001:10001(8000) ack 1

// RTO
+.188 &gt; . 1:1001(1000) ack 1

// The original data is acked and new data is sent(F-RTO step 2.b)
   +0 &lt; . 1:1(0) ack 2001 win 257
   +0 &gt; P. 10001:12001(2000) ack 1

// D-SACK caused by TLP is regarded as a dupack, this results in
// the incorrect judgment of "loss was real"(F-RTO step 3.a)
+.022 &lt; . 1:1(0) ack 2001 win 257 &lt;sack 1001:2001,nop,nop&gt;

// Never-retransmitted data(3001:4001) are acked and
// expect to switch to open state(F-RTO step 3.b)
   +0 &lt; . 1:1(0) ack 4001 win 257
+0 %{ assert tcpi_ca_state == 0, tcpi_ca_state }%

Fixes: e33099f96d99 ("tcp: implement RFC5682 F-RTO")
Signed-off-by: Pengcheng Yang &lt;yangpc@wangsu.com&gt;
Acked-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Tested-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Link: https://lore.kernel.org/r/1650967419-2150-1-git-send-email-yangpc@wangsu.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf</title>
<updated>2022-04-28T16:56:00+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2022-04-28T16:55:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c26d0d988edddcd8c19ba59b5bc93a0cabcb6cc7'/>
<id>c26d0d988edddcd8c19ba59b5bc93a0cabcb6cc7</id>
<content type='text'>
Pablo Neira Ayuso says:

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

1) Fix incorrect TCP connection tracking window reset for non-syn
   packets, from Florian Westphal.

2) Incorrect dependency on CONFIG_NFT_FLOW_OFFLOAD, from Volodymyr Mytnyk.

3) Fix nft_socket from the output path, from Florian Westphal.

* git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nft_socket: only do sk lookups when indev is available
  netfilter: conntrack: fix udp offload timeout sysctl
  netfilter: nf_conntrack_tcp: re-init for syn packets only
====================

Link: https://lore.kernel.org/r/20220428142109.38726-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pablo Neira Ayuso says:

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

1) Fix incorrect TCP connection tracking window reset for non-syn
   packets, from Florian Westphal.

2) Incorrect dependency on CONFIG_NFT_FLOW_OFFLOAD, from Volodymyr Mytnyk.

3) Fix nft_socket from the output path, from Florian Westphal.

* git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nft_socket: only do sk lookups when indev is available
  netfilter: conntrack: fix udp offload timeout sysctl
  netfilter: nf_conntrack_tcp: re-init for syn packets only
====================

Link: https://lore.kernel.org/r/20220428142109.38726-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: nft_socket: only do sk lookups when indev is available</title>
<updated>2022-04-28T14:15:23+00:00</updated>
<author>
<name>Florian Westphal</name>
<email>fw@strlen.de</email>
</author>
<published>2022-04-28T07:39:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=743b83f15d4069ea57c3e40996bf4a1077e0cdc1'/>
<id>743b83f15d4069ea57c3e40996bf4a1077e0cdc1</id>
<content type='text'>
Check if the incoming interface is available and NFT_BREAK
in case neither skb-&gt;sk nor input device are set.

Because nf_sk_lookup_slow*() assume packet headers are in the
'in' direction, use in postrouting is not going to yield a meaningful
result.  Same is true for the forward chain, so restrict the use
to prerouting, input and output.

Use in output work if a socket is already attached to the skb.

Fixes: 554ced0a6e29 ("netfilter: nf_tables: add support for native socket matching")
Reported-and-tested-by: Topi Miettinen &lt;toiwoton@gmail.com&gt;
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Check if the incoming interface is available and NFT_BREAK
in case neither skb-&gt;sk nor input device are set.

Because nf_sk_lookup_slow*() assume packet headers are in the
'in' direction, use in postrouting is not going to yield a meaningful
result.  Same is true for the forward chain, so restrict the use
to prerouting, input and output.

Use in output work if a socket is already attached to the skb.

Fixes: 554ced0a6e29 ("netfilter: nf_tables: add support for native socket matching")
Reported-and-tested-by: Topi Miettinen &lt;toiwoton@gmail.com&gt;
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-net-2022-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth</title>
<updated>2022-04-28T08:18:51+00:00</updated>
<author>
<name>Paolo Abeni</name>
<email>pabeni@redhat.com</email>
</author>
<published>2022-04-28T08:18:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=febb2d2fa5619b0ff08e1e2793a29bebf17319d5'/>
<id>febb2d2fa5619b0ff08e1e2793a29bebf17319d5</id>
<content type='text'>
Luiz Augusto von Dentz says:

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

 - Fix regression causing some HCI events to be discarded when they
   shouldn't.

* tag 'for-net-2022-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth:
  Bluetooth: hci_sync: Cleanup hci_conn if it cannot be aborted
  Bluetooth: hci_event: Fix creating hci_conn object on error status
  Bluetooth: hci_event: Fix checking for invalid handle on error status
====================

Link: https://lore.kernel.org/r/20220427234031.1257281-1-luiz.dentz@gmail.com
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Luiz Augusto von Dentz says:

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

 - Fix regression causing some HCI events to be discarded when they
   shouldn't.

* tag 'for-net-2022-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth:
  Bluetooth: hci_sync: Cleanup hci_conn if it cannot be aborted
  Bluetooth: hci_event: Fix creating hci_conn object on error status
  Bluetooth: hci_event: Fix checking for invalid handle on error status
====================

Link: https://lore.kernel.org/r/20220427234031.1257281-1-luiz.dentz@gmail.com
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tls: Skip tls_append_frag on zero copy size</title>
<updated>2022-04-27T22:25:20+00:00</updated>
<author>
<name>Maxim Mikityanskiy</name>
<email>maximmi@nvidia.com</email>
</author>
<published>2022-04-26T15:49:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a0df71948e9548de819a6f1da68f5f1742258a52'/>
<id>a0df71948e9548de819a6f1da68f5f1742258a52</id>
<content type='text'>
Calling tls_append_frag when max_open_record_len == record-&gt;len might
add an empty fragment to the TLS record if the call happens to be on the
page boundary. Normally tls_append_frag coalesces the zero-sized
fragment to the previous one, but not if it's on page boundary.

If a resync happens then, the mlx5 driver posts dump WQEs in
tx_post_resync_dump, and the empty fragment may become a data segment
with byte_count == 0, which will confuse the NIC and lead to a CQE
error.

This commit fixes the described issue by skipping tls_append_frag on
zero size to avoid adding empty fragments. The fix is not in the driver,
because an empty fragment is hardly the desired behavior.

Fixes: e8f69799810c ("net/tls: Add generic NIC offload infrastructure")
Signed-off-by: Maxim Mikityanskiy &lt;maximmi@nvidia.com&gt;
Reviewed-by: Tariq Toukan &lt;tariqt@nvidia.com&gt;
Link: https://lore.kernel.org/r/20220426154949.159055-1-maximmi@nvidia.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Calling tls_append_frag when max_open_record_len == record-&gt;len might
add an empty fragment to the TLS record if the call happens to be on the
page boundary. Normally tls_append_frag coalesces the zero-sized
fragment to the previous one, but not if it's on page boundary.

If a resync happens then, the mlx5 driver posts dump WQEs in
tx_post_resync_dump, and the empty fragment may become a data segment
with byte_count == 0, which will confuse the NIC and lead to a CQE
error.

This commit fixes the described issue by skipping tls_append_frag on
zero size to avoid adding empty fragments. The fix is not in the driver,
because an empty fragment is hardly the desired behavior.

Fixes: e8f69799810c ("net/tls: Add generic NIC offload infrastructure")
Signed-off-by: Maxim Mikityanskiy &lt;maximmi@nvidia.com&gt;
Reviewed-by: Tariq Toukan &lt;tariqt@nvidia.com&gt;
Link: https://lore.kernel.org/r/20220426154949.159055-1-maximmi@nvidia.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf</title>
<updated>2022-04-27T22:18:40+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2022-04-27T22:18:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=347cb5deae253c292cebcc5fdf1d07a710904a47'/>
<id>347cb5deae253c292cebcc5fdf1d07a710904a47</id>
<content type='text'>
Daniel Borkmann says:

====================
pull-request: bpf 2022-04-27

We've added 5 non-merge commits during the last 20 day(s) which contain
a total of 6 files changed, 34 insertions(+), 12 deletions(-).

The main changes are:

1) Fix xsk sockets when rx and tx are separately bound to the same umem, also
   fix xsk copy mode combined with busy poll, from Maciej Fijalkowski.

2) Fix BPF tunnel/collect_md helpers with bpf_xmit lwt hook usage which triggered
   a crash due to invalid metadata_dst access, from Eyal Birger.

3) Fix release of page pool in XDP live packet mode, from Toke Høiland-Jørgensen.

4) Fix potential NULL pointer dereference in kretprobes, from Adam Zabrocki.

   (Masami &amp; Steven preferred this small fix to be routed via bpf tree given it's
    follow-up fix to Masami's rethook work that went via bpf earlier, too.)

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  xsk: Fix possible crash when multiple sockets are created
  kprobes: Fix KRETPROBES when CONFIG_KRETPROBE_ON_RETHOOK is set
  bpf, lwt: Fix crash when using bpf_skb_set_tunnel_key() from bpf_xmit lwt hook
  bpf: Fix release of page_pool in BPF_PROG_RUN in test runner
  xsk: Fix l2fwd for copy mode + busy poll combo
====================

Link: https://lore.kernel.org/r/20220427212748.9576-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Daniel Borkmann says:

====================
pull-request: bpf 2022-04-27

We've added 5 non-merge commits during the last 20 day(s) which contain
a total of 6 files changed, 34 insertions(+), 12 deletions(-).

The main changes are:

1) Fix xsk sockets when rx and tx are separately bound to the same umem, also
   fix xsk copy mode combined with busy poll, from Maciej Fijalkowski.

2) Fix BPF tunnel/collect_md helpers with bpf_xmit lwt hook usage which triggered
   a crash due to invalid metadata_dst access, from Eyal Birger.

3) Fix release of page pool in XDP live packet mode, from Toke Høiland-Jørgensen.

4) Fix potential NULL pointer dereference in kretprobes, from Adam Zabrocki.

   (Masami &amp; Steven preferred this small fix to be routed via bpf tree given it's
    follow-up fix to Masami's rethook work that went via bpf earlier, too.)

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  xsk: Fix possible crash when multiple sockets are created
  kprobes: Fix KRETPROBES when CONFIG_KRETPROBE_ON_RETHOOK is set
  bpf, lwt: Fix crash when using bpf_skb_set_tunnel_key() from bpf_xmit lwt hook
  bpf: Fix release of page_pool in BPF_PROG_RUN in test runner
  xsk: Fix l2fwd for copy mode + busy poll combo
====================

Link: https://lore.kernel.org/r/20220427212748.9576-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: conntrack: fix udp offload timeout sysctl</title>
<updated>2022-04-27T13:48:49+00:00</updated>
<author>
<name>Volodymyr Mytnyk</name>
<email>volodymyr.mytnyk@plvision.eu</email>
</author>
<published>2022-04-27T11:09:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=626873c446f7559d5af8b48cefad903ffd85cf4e'/>
<id>626873c446f7559d5af8b48cefad903ffd85cf4e</id>
<content type='text'>
`nf_flowtable_udp_timeout` sysctl option is available only
if CONFIG_NFT_FLOW_OFFLOAD enabled. But infra for this flow
offload UDP timeout was added under CONFIG_NF_FLOW_TABLE
config option. So, if you have CONFIG_NFT_FLOW_OFFLOAD
disabled and CONFIG_NF_FLOW_TABLE enabled, the
`nf_flowtable_udp_timeout` is not present in sysfs.
Please note, that TCP flow offload timeout sysctl option
is present even CONFIG_NFT_FLOW_OFFLOAD is disabled.

I suppose it was a typo in commit that adds UDP flow offload
timeout and CONFIG_NF_FLOW_TABLE should be used instead.

Fixes: 975c57504da1 ("netfilter: conntrack: Introduce udp offload timeout configuration")
Signed-off-by: Volodymyr Mytnyk &lt;volodymyr.mytnyk@plvision.eu&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
`nf_flowtable_udp_timeout` sysctl option is available only
if CONFIG_NFT_FLOW_OFFLOAD enabled. But infra for this flow
offload UDP timeout was added under CONFIG_NF_FLOW_TABLE
config option. So, if you have CONFIG_NFT_FLOW_OFFLOAD
disabled and CONFIG_NF_FLOW_TABLE enabled, the
`nf_flowtable_udp_timeout` is not present in sysfs.
Please note, that TCP flow offload timeout sysctl option
is present even CONFIG_NFT_FLOW_OFFLOAD is disabled.

I suppose it was a typo in commit that adds UDP flow offload
timeout and CONFIG_NF_FLOW_TABLE should be used instead.

Fixes: 975c57504da1 ("netfilter: conntrack: Introduce udp offload timeout configuration")
Signed-off-by: Volodymyr Mytnyk &lt;volodymyr.mytnyk@plvision.eu&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: nf_conntrack_tcp: re-init for syn packets only</title>
<updated>2022-04-27T13:48:45+00:00</updated>
<author>
<name>Florian Westphal</name>
<email>fw@strlen.de</email>
</author>
<published>2022-04-25T09:47:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c7aab4f17021b636a0ee75bcf28e06fb7c94ab48'/>
<id>c7aab4f17021b636a0ee75bcf28e06fb7c94ab48</id>
<content type='text'>
Jaco Kroon reported tcp problems that Eric Dumazet and Neal Cardwell
pinpointed to nf_conntrack tcp_in_window() bug.

tcp trace shows following sequence:

I &gt; R Flags [S], seq 3451342529, win 62580, options [.. tfo [|tcp]&gt;
R &gt; I Flags [S.], seq 2699962254, ack 3451342530, win 65535, options [..]
R &gt; I Flags [P.], seq 1:89, ack 1, [..]

Note 3rd ACK is from responder to initiator so following branch is taken:
    } else if (((state-&gt;state == TCP_CONNTRACK_SYN_SENT
               &amp;&amp; dir == IP_CT_DIR_ORIGINAL)
               || (state-&gt;state == TCP_CONNTRACK_SYN_RECV
               &amp;&amp; dir == IP_CT_DIR_REPLY))
               &amp;&amp; after(end, sender-&gt;td_end)) {

... because state == TCP_CONNTRACK_SYN_RECV and dir is REPLY.
This causes the scaling factor to be reset to 0: window scale option
is only present in syn(ack) packets.  This in turn makes nf_conntrack
mark valid packets as out-of-window.

This was always broken, it exists even in original commit where
window tracking was added to ip_conntrack (nf_conntrack predecessor)
in 2.6.9-rc1 kernel.

Restrict to 'tcph-&gt;syn', just like the 3rd condtional added in
commit 82b72cb94666 ("netfilter: conntrack: re-init state for retransmitted syn-ack").

Upon closer look, those conditionals/branches can be merged:

Because earlier checks prevent syn-ack from showing up in
original direction, the 'dir' checks in the conditional quoted above are
redundant, remove them. Return early for pure syn retransmitted in reply
direction (simultaneous open).

Fixes: 9fb9cbb1082d ("[NETFILTER]: Add nf_conntrack subsystem.")
Reported-by: Jaco Kroon &lt;jaco@uls.co.za&gt;
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Acked-by: Jozsef Kadlecsik &lt;kadlec@netfilter.org&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
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<pre>
Jaco Kroon reported tcp problems that Eric Dumazet and Neal Cardwell
pinpointed to nf_conntrack tcp_in_window() bug.

tcp trace shows following sequence:

I &gt; R Flags [S], seq 3451342529, win 62580, options [.. tfo [|tcp]&gt;
R &gt; I Flags [S.], seq 2699962254, ack 3451342530, win 65535, options [..]
R &gt; I Flags [P.], seq 1:89, ack 1, [..]

Note 3rd ACK is from responder to initiator so following branch is taken:
    } else if (((state-&gt;state == TCP_CONNTRACK_SYN_SENT
               &amp;&amp; dir == IP_CT_DIR_ORIGINAL)
               || (state-&gt;state == TCP_CONNTRACK_SYN_RECV
               &amp;&amp; dir == IP_CT_DIR_REPLY))
               &amp;&amp; after(end, sender-&gt;td_end)) {

... because state == TCP_CONNTRACK_SYN_RECV and dir is REPLY.
This causes the scaling factor to be reset to 0: window scale option
is only present in syn(ack) packets.  This in turn makes nf_conntrack
mark valid packets as out-of-window.

This was always broken, it exists even in original commit where
window tracking was added to ip_conntrack (nf_conntrack predecessor)
in 2.6.9-rc1 kernel.

Restrict to 'tcph-&gt;syn', just like the 3rd condtional added in
commit 82b72cb94666 ("netfilter: conntrack: re-init state for retransmitted syn-ack").

Upon closer look, those conditionals/branches can be merged:

Because earlier checks prevent syn-ack from showing up in
original direction, the 'dir' checks in the conditional quoted above are
redundant, remove them. Return early for pure syn retransmitted in reply
direction (simultaneous open).

Fixes: 9fb9cbb1082d ("[NETFILTER]: Add nf_conntrack subsystem.")
Reported-by: Jaco Kroon &lt;jaco@uls.co.za&gt;
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Acked-by: Jozsef Kadlecsik &lt;kadlec@netfilter.org&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
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</content>
</entry>
<entry>
<title>net: Use this_cpu_inc() to increment net-&gt;core_stats</title>
<updated>2022-04-27T00:32:30+00:00</updated>
<author>
<name>Sebastian Andrzej Siewior</name>
<email>bigeasy@linutronix.de</email>
</author>
<published>2022-04-25T16:39:46+00:00</published>
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<id>6510ea973d8d9d4a0cb2fb557b36bd1ab3eb49f6</id>
<content type='text'>
The macro dev_core_stats_##FIELD##_inc() disables preemption and invokes
netdev_core_stats_alloc() to return a per-CPU pointer.
netdev_core_stats_alloc() will allocate memory on its first invocation
which breaks on PREEMPT_RT because it requires non-atomic context for
memory allocation.

This can be avoided by enabling preemption in netdev_core_stats_alloc()
assuming the caller always disables preemption.

It might be better to replace local_inc() with this_cpu_inc() now that
dev_core_stats_##FIELD##_inc() gained a preempt-disable section and does
not rely on already disabled preemption. This results in less
instructions on x86-64:
local_inc:
|          incl %gs:__preempt_count(%rip)  # __preempt_count
|          movq    488(%rdi), %rax # _1-&gt;core_stats, _22
|          testq   %rax, %rax      # _22
|          je      .L585   #,
|          add %gs:this_cpu_off(%rip), %rax        # this_cpu_off, tcp_ptr__
|  .L586:
|          testq   %rax, %rax      # _27
|          je      .L587   #,
|          incq (%rax)            # _6-&gt;a.counter
|  .L587:
|          decl %gs:__preempt_count(%rip)  # __preempt_count

this_cpu_inc(), this patch:
|         movq    488(%rdi), %rax # _1-&gt;core_stats, _5
|         testq   %rax, %rax      # _5
|         je      .L591   #,
| .L585:
|         incq %gs:(%rax) # _18-&gt;rx_dropped

Use unsigned long as type for the counter. Use this_cpu_inc() to
increment the counter. Use a plain read of the counter.

Signed-off-by: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Link: https://lore.kernel.org/r/YmbO0pxgtKpCw4SY@linutronix.de
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The macro dev_core_stats_##FIELD##_inc() disables preemption and invokes
netdev_core_stats_alloc() to return a per-CPU pointer.
netdev_core_stats_alloc() will allocate memory on its first invocation
which breaks on PREEMPT_RT because it requires non-atomic context for
memory allocation.

This can be avoided by enabling preemption in netdev_core_stats_alloc()
assuming the caller always disables preemption.

It might be better to replace local_inc() with this_cpu_inc() now that
dev_core_stats_##FIELD##_inc() gained a preempt-disable section and does
not rely on already disabled preemption. This results in less
instructions on x86-64:
local_inc:
|          incl %gs:__preempt_count(%rip)  # __preempt_count
|          movq    488(%rdi), %rax # _1-&gt;core_stats, _22
|          testq   %rax, %rax      # _22
|          je      .L585   #,
|          add %gs:this_cpu_off(%rip), %rax        # this_cpu_off, tcp_ptr__
|  .L586:
|          testq   %rax, %rax      # _27
|          je      .L587   #,
|          incq (%rax)            # _6-&gt;a.counter
|  .L587:
|          decl %gs:__preempt_count(%rip)  # __preempt_count

this_cpu_inc(), this patch:
|         movq    488(%rdi), %rax # _1-&gt;core_stats, _5
|         testq   %rax, %rax      # _5
|         je      .L591   #,
| .L585:
|         incq %gs:(%rax) # _18-&gt;rx_dropped

Use unsigned long as type for the counter. Use this_cpu_inc() to
increment the counter. Use a plain read of the counter.

Signed-off-by: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Link: https://lore.kernel.org/r/YmbO0pxgtKpCw4SY@linutronix.de
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
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