<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/net, branch v6.8-rc7</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'for-net-2024-02-28' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth</title>
<updated>2024-02-29T17:10:24+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2024-02-29T17:10:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=244b96c2310ef7bba7569bbaca1633feea627af9'/>
<id>244b96c2310ef7bba7569bbaca1633feea627af9</id>
<content type='text'>
Luiz Augusto von Dentz says:

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

 - mgmt: Fix limited discoverable off timeout
 - hci_qca: Set BDA quirk bit if fwnode exists in DT
 - hci_bcm4377: do not mark valid bd_addr as invalid
 - hci_sync: Check the correct flag before starting a scan
 - Enforce validation on max value of connection interval
 - hci_sync: Fix accept_list when attempting to suspend
 - hci_event: Fix handling of HCI_EV_IO_CAPA_REQUEST
 - Avoid potential use-after-free in hci_error_reset
 - rfcomm: Fix null-ptr-deref in rfcomm_check_security
 - hci_event: Fix wrongly recorded wakeup BD_ADDR
 - qca: Fix wrong event type for patch config command
 - qca: Fix triggering coredump implementation

* tag 'for-net-2024-02-28' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth:
  Bluetooth: qca: Fix triggering coredump implementation
  Bluetooth: hci_qca: Set BDA quirk bit if fwnode exists in DT
  Bluetooth: qca: Fix wrong event type for patch config command
  Bluetooth: Enforce validation on max value of connection interval
  Bluetooth: hci_event: Fix handling of HCI_EV_IO_CAPA_REQUEST
  Bluetooth: mgmt: Fix limited discoverable off timeout
  Bluetooth: hci_event: Fix wrongly recorded wakeup BD_ADDR
  Bluetooth: rfcomm: Fix null-ptr-deref in rfcomm_check_security
  Bluetooth: hci_sync: Fix accept_list when attempting to suspend
  Bluetooth: Avoid potential use-after-free in hci_error_reset
  Bluetooth: hci_sync: Check the correct flag before starting a scan
  Bluetooth: hci_bcm4377: do not mark valid bd_addr as invalid
====================

Link: https://lore.kernel.org/r/20240228145644.2269088-1-luiz.dentz@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Luiz Augusto von Dentz says:

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

 - mgmt: Fix limited discoverable off timeout
 - hci_qca: Set BDA quirk bit if fwnode exists in DT
 - hci_bcm4377: do not mark valid bd_addr as invalid
 - hci_sync: Check the correct flag before starting a scan
 - Enforce validation on max value of connection interval
 - hci_sync: Fix accept_list when attempting to suspend
 - hci_event: Fix handling of HCI_EV_IO_CAPA_REQUEST
 - Avoid potential use-after-free in hci_error_reset
 - rfcomm: Fix null-ptr-deref in rfcomm_check_security
 - hci_event: Fix wrongly recorded wakeup BD_ADDR
 - qca: Fix wrong event type for patch config command
 - qca: Fix triggering coredump implementation

* tag 'for-net-2024-02-28' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth:
  Bluetooth: qca: Fix triggering coredump implementation
  Bluetooth: hci_qca: Set BDA quirk bit if fwnode exists in DT
  Bluetooth: qca: Fix wrong event type for patch config command
  Bluetooth: Enforce validation on max value of connection interval
  Bluetooth: hci_event: Fix handling of HCI_EV_IO_CAPA_REQUEST
  Bluetooth: mgmt: Fix limited discoverable off timeout
  Bluetooth: hci_event: Fix wrongly recorded wakeup BD_ADDR
  Bluetooth: rfcomm: Fix null-ptr-deref in rfcomm_check_security
  Bluetooth: hci_sync: Fix accept_list when attempting to suspend
  Bluetooth: Avoid potential use-after-free in hci_error_reset
  Bluetooth: hci_sync: Check the correct flag before starting a scan
  Bluetooth: hci_bcm4377: do not mark valid bd_addr as invalid
====================

Link: https://lore.kernel.org/r/20240228145644.2269088-1-luiz.dentz@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tls: fix use-after-free on failed backlog decryption</title>
<updated>2024-02-29T17:07:16+00:00</updated>
<author>
<name>Sabrina Dubroca</name>
<email>sd@queasysnail.net</email>
</author>
<published>2024-02-28T22:44:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=13114dc5543069f7b97991e3b79937b6da05f5b0'/>
<id>13114dc5543069f7b97991e3b79937b6da05f5b0</id>
<content type='text'>
When the decrypt request goes to the backlog and crypto_aead_decrypt
returns -EBUSY, tls_do_decryption will wait until all async
decryptions have completed. If one of them fails, tls_do_decryption
will return -EBADMSG and tls_decrypt_sg jumps to the error path,
releasing all the pages. But the pages have been passed to the async
callback, and have already been released by tls_decrypt_done.

The only true async case is when crypto_aead_decrypt returns
 -EINPROGRESS. With -EBUSY, we already waited so we can tell
tls_sw_recvmsg that the data is available for immediate copy, but we
need to notify tls_decrypt_sg (via the new -&gt;async_done flag) that the
memory has already been released.

Fixes: 859054147318 ("net: tls: handle backlogging of crypto requests")
Signed-off-by: Sabrina Dubroca &lt;sd@queasysnail.net&gt;
Link: https://lore.kernel.org/r/4755dd8d9bebdefaa19ce1439b833d6199d4364c.1709132643.git.sd@queasysnail.net
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When the decrypt request goes to the backlog and crypto_aead_decrypt
returns -EBUSY, tls_do_decryption will wait until all async
decryptions have completed. If one of them fails, tls_do_decryption
will return -EBADMSG and tls_decrypt_sg jumps to the error path,
releasing all the pages. But the pages have been passed to the async
callback, and have already been released by tls_decrypt_done.

The only true async case is when crypto_aead_decrypt returns
 -EINPROGRESS. With -EBUSY, we already waited so we can tell
tls_sw_recvmsg that the data is available for immediate copy, but we
need to notify tls_decrypt_sg (via the new -&gt;async_done flag) that the
memory has already been released.

Fixes: 859054147318 ("net: tls: handle backlogging of crypto requests")
Signed-off-by: Sabrina Dubroca &lt;sd@queasysnail.net&gt;
Link: https://lore.kernel.org/r/4755dd8d9bebdefaa19ce1439b833d6199d4364c.1709132643.git.sd@queasysnail.net
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tls: separate no-async decryption request handling from async</title>
<updated>2024-02-29T17:07:16+00:00</updated>
<author>
<name>Sabrina Dubroca</name>
<email>sd@queasysnail.net</email>
</author>
<published>2024-02-28T22:43:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=41532b785e9d79636b3815a64ddf6a096647d011'/>
<id>41532b785e9d79636b3815a64ddf6a096647d011</id>
<content type='text'>
If we're not doing async, the handling is much simpler. There's no
reference counting, we just need to wait for the completion to wake us
up and return its result.

We should preferably also use a separate crypto_wait. I'm not seeing a
UAF as I did in the past, I think aec7961916f3 ("tls: fix race between
async notify and socket close") took care of it.

This will make the next fix easier.

Signed-off-by: Sabrina Dubroca &lt;sd@queasysnail.net&gt;
Link: https://lore.kernel.org/r/47bde5f649707610eaef9f0d679519966fc31061.1709132643.git.sd@queasysnail.net
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If we're not doing async, the handling is much simpler. There's no
reference counting, we just need to wait for the completion to wake us
up and return its result.

We should preferably also use a separate crypto_wait. I'm not seeing a
UAF as I did in the past, I think aec7961916f3 ("tls: fix race between
async notify and socket close") took care of it.

This will make the next fix easier.

Signed-off-by: Sabrina Dubroca &lt;sd@queasysnail.net&gt;
Link: https://lore.kernel.org/r/47bde5f649707610eaef9f0d679519966fc31061.1709132643.git.sd@queasysnail.net
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tls: fix peeking with sync+async decryption</title>
<updated>2024-02-29T17:07:16+00:00</updated>
<author>
<name>Sabrina Dubroca</name>
<email>sd@queasysnail.net</email>
</author>
<published>2024-02-28T22:43:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6caaf104423d809b49a67ee6500191d063b40dc6'/>
<id>6caaf104423d809b49a67ee6500191d063b40dc6</id>
<content type='text'>
If we peek from 2 records with a currently empty rx_list, and the
first record is decrypted synchronously but the second record is
decrypted async, the following happens:
  1. decrypt record 1 (sync)
  2. copy from record 1 to the userspace's msg
  3. queue the decrypted record to rx_list for future read(!PEEK)
  4. decrypt record 2 (async)
  5. queue record 2 to rx_list
  6. call process_rx_list to copy data from the 2nd record

We currently pass copied=0 as skip offset to process_rx_list, so we
end up copying once again from the first record. We should skip over
the data we've already copied.

Seen with selftest tls.12_aes_gcm.recv_peek_large_buf_mult_recs

Fixes: 692d7b5d1f91 ("tls: Fix recvmsg() to be able to peek across multiple records")
Signed-off-by: Sabrina Dubroca &lt;sd@queasysnail.net&gt;
Link: https://lore.kernel.org/r/1b132d2b2b99296bfde54e8a67672d90d6d16e71.1709132643.git.sd@queasysnail.net
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If we peek from 2 records with a currently empty rx_list, and the
first record is decrypted synchronously but the second record is
decrypted async, the following happens:
  1. decrypt record 1 (sync)
  2. copy from record 1 to the userspace's msg
  3. queue the decrypted record to rx_list for future read(!PEEK)
  4. decrypt record 2 (async)
  5. queue record 2 to rx_list
  6. call process_rx_list to copy data from the 2nd record

We currently pass copied=0 as skip offset to process_rx_list, so we
end up copying once again from the first record. We should skip over
the data we've already copied.

Seen with selftest tls.12_aes_gcm.recv_peek_large_buf_mult_recs

Fixes: 692d7b5d1f91 ("tls: Fix recvmsg() to be able to peek across multiple records")
Signed-off-by: Sabrina Dubroca &lt;sd@queasysnail.net&gt;
Link: https://lore.kernel.org/r/1b132d2b2b99296bfde54e8a67672d90d6d16e71.1709132643.git.sd@queasysnail.net
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tls: decrement decrypt_pending if no async completion will be called</title>
<updated>2024-02-29T17:07:16+00:00</updated>
<author>
<name>Sabrina Dubroca</name>
<email>sd@queasysnail.net</email>
</author>
<published>2024-02-28T22:43:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f7fa16d49837f947ee59492958f9e6f0e51d9a78'/>
<id>f7fa16d49837f947ee59492958f9e6f0e51d9a78</id>
<content type='text'>
With mixed sync/async decryption, or failures of crypto_aead_decrypt,
we increment decrypt_pending but we never do the corresponding
decrement since tls_decrypt_done will not be called. In this case, we
should decrement decrypt_pending immediately to avoid getting stuck.

For example, the prequeue prequeue test gets stuck with mixed
modes (one async decrypt + one sync decrypt).

Fixes: 94524d8fc965 ("net/tls: Add support for async decryption of tls records")
Signed-off-by: Sabrina Dubroca &lt;sd@queasysnail.net&gt;
Link: https://lore.kernel.org/r/c56d5fc35543891d5319f834f25622360e1bfbec.1709132643.git.sd@queasysnail.net
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
With mixed sync/async decryption, or failures of crypto_aead_decrypt,
we increment decrypt_pending but we never do the corresponding
decrement since tls_decrypt_done will not be called. In this case, we
should decrement decrypt_pending immediately to avoid getting stuck.

For example, the prequeue prequeue test gets stuck with mixed
modes (one async decrypt + one sync decrypt).

Fixes: 94524d8fc965 ("net/tls: Add support for async decryption of tls records")
Signed-off-by: Sabrina Dubroca &lt;sd@queasysnail.net&gt;
Link: https://lore.kernel.org/r/c56d5fc35543891d5319f834f25622360e1bfbec.1709132643.git.sd@queasysnail.net
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'nf-24-02-29' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf</title>
<updated>2024-02-29T11:16:08+00:00</updated>
<author>
<name>Paolo Abeni</name>
<email>pabeni@redhat.com</email>
</author>
<published>2024-02-29T11:16:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b611b776a9c89a86e57ea6dbf8adfc99c6e8a62e'/>
<id>b611b776a9c89a86e57ea6dbf8adfc99c6e8a62e</id>
<content type='text'>
Pablo Neira Ayuso says:

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

Patch #1 restores NFPROTO_INET with nft_compat, from Ignat Korchagin.

Patch #2 fixes an issue with bridge netfilter and broadcast/multicast
packets.

There is a day 0 bug in br_netfilter when used with connection tracking.

Conntrack assumes that an nf_conn structure that is not yet added to
hash table ("unconfirmed"), is only visible by the current cpu that is
processing the sk_buff.

For bridge this isn't true, sk_buff can get cloned in between, and
clones can be processed in parallel on different cpu.

This patch disables NAT and conntrack helpers for multicast packets.

Patch #3 adds a selftest to cover for the br_netfilter bug.

netfilter pull request 24-02-29

* tag 'nf-24-02-29' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  selftests: netfilter: add bridge conntrack + multicast test case
  netfilter: bridge: confirm multicast packets before passing them up the stack
  netfilter: nf_tables: allow NFPROTO_INET in nft_(match/target)_validate()
====================

Link: https://lore.kernel.org/r/20240229000135.8780-1-pablo@netfilter.org
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pablo Neira Ayuso says:

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

Patch #1 restores NFPROTO_INET with nft_compat, from Ignat Korchagin.

Patch #2 fixes an issue with bridge netfilter and broadcast/multicast
packets.

There is a day 0 bug in br_netfilter when used with connection tracking.

Conntrack assumes that an nf_conn structure that is not yet added to
hash table ("unconfirmed"), is only visible by the current cpu that is
processing the sk_buff.

For bridge this isn't true, sk_buff can get cloned in between, and
clones can be processed in parallel on different cpu.

This patch disables NAT and conntrack helpers for multicast packets.

Patch #3 adds a selftest to cover for the br_netfilter bug.

netfilter pull request 24-02-29

* tag 'nf-24-02-29' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  selftests: netfilter: add bridge conntrack + multicast test case
  netfilter: bridge: confirm multicast packets before passing them up the stack
  netfilter: nf_tables: allow NFPROTO_INET in nft_(match/target)_validate()
====================

Link: https://lore.kernel.org/r/20240229000135.8780-1-pablo@netfilter.org
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: hsr: Use correct offset for HSR TLV values in supervisory HSR frames</title>
<updated>2024-02-29T09:42:46+00:00</updated>
<author>
<name>Lukasz Majewski</name>
<email>lukma@denx.de</email>
</author>
<published>2024-02-28T08:56:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=51dd4ee0372228ffb0f7709fa7aa0678d4199d06'/>
<id>51dd4ee0372228ffb0f7709fa7aa0678d4199d06</id>
<content type='text'>
Current HSR implementation uses following supervisory frame (even for
HSRv1 the HSR tag is not is not present):

00000000: 01 15 4e 00 01 2d XX YY ZZ 94 77 10 88 fb 00 01
00000010: 7e 1c 17 06 XX YY ZZ 94 77 10 1e 06 XX YY ZZ 94
00000020: 77 10 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000030: 00 00 00 00 00 00 00 00 00 00 00 00

The current code adds extra two bytes (i.e. sizeof(struct hsr_sup_tlv))
when offset for skb_pull() is calculated.
This is wrong, as both 'struct hsrv1_ethhdr_sp' and 'hsrv0_ethhdr_sp'
already have 'struct hsr_sup_tag' defined in them, so there is no need
for adding extra two bytes.

This code was working correctly as with no RedBox support, the check for
HSR_TLV_EOT (0x00) was off by two bytes, which were corresponding to
zeroed padded bytes for minimal packet size.

Fixes: eafaa88b3eb7 ("net: hsr: Add support for redbox supervision frames")
Signed-off-by: Lukasz Majewski &lt;lukma@denx.de&gt;
Reviewed-by: Jiri Pirko &lt;jiri@nvidia.com&gt;
Link: https://lore.kernel.org/r/20240228085644.3618044-1-lukma@denx.de
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Current HSR implementation uses following supervisory frame (even for
HSRv1 the HSR tag is not is not present):

00000000: 01 15 4e 00 01 2d XX YY ZZ 94 77 10 88 fb 00 01
00000010: 7e 1c 17 06 XX YY ZZ 94 77 10 1e 06 XX YY ZZ 94
00000020: 77 10 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000030: 00 00 00 00 00 00 00 00 00 00 00 00

The current code adds extra two bytes (i.e. sizeof(struct hsr_sup_tlv))
when offset for skb_pull() is calculated.
This is wrong, as both 'struct hsrv1_ethhdr_sp' and 'hsrv0_ethhdr_sp'
already have 'struct hsr_sup_tag' defined in them, so there is no need
for adding extra two bytes.

This code was working correctly as with no RedBox support, the check for
HSR_TLV_EOT (0x00) was off by two bytes, which were corresponding to
zeroed padded bytes for minimal packet size.

Fixes: eafaa88b3eb7 ("net: hsr: Add support for redbox supervision frames")
Signed-off-by: Lukasz Majewski &lt;lukma@denx.de&gt;
Reviewed-by: Jiri Pirko &lt;jiri@nvidia.com&gt;
Link: https://lore.kernel.org/r/20240228085644.3618044-1-lukma@denx.de
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rtnetlink: fix error logic of IFLA_BRIDGE_FLAGS writing back</title>
<updated>2024-02-29T03:38:03+00:00</updated>
<author>
<name>Lin Ma</name>
<email>linma@zju.edu.cn</email>
</author>
<published>2024-02-27T12:11:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=743ad091fb46e622f1b690385bb15e3cd3daf874'/>
<id>743ad091fb46e622f1b690385bb15e3cd3daf874</id>
<content type='text'>
In the commit d73ef2d69c0d ("rtnetlink: let rtnl_bridge_setlink checks
IFLA_BRIDGE_MODE length"), an adjustment was made to the old loop logic
in the function `rtnl_bridge_setlink` to enable the loop to also check
the length of the IFLA_BRIDGE_MODE attribute. However, this adjustment
removed the `break` statement and led to an error logic of the flags
writing back at the end of this function.

if (have_flags)
    memcpy(nla_data(attr), &amp;flags, sizeof(flags));
    // attr should point to IFLA_BRIDGE_FLAGS NLA !!!

Before the mentioned commit, the `attr` is granted to be IFLA_BRIDGE_FLAGS.
However, this is not necessarily true fow now as the updated loop will let
the attr point to the last NLA, even an invalid NLA which could cause
overflow writes.

This patch introduces a new variable `br_flag` to save the NLA pointer
that points to IFLA_BRIDGE_FLAGS and uses it to resolve the mentioned
error logic.

Fixes: d73ef2d69c0d ("rtnetlink: let rtnl_bridge_setlink checks IFLA_BRIDGE_MODE length")
Signed-off-by: Lin Ma &lt;linma@zju.edu.cn&gt;
Acked-by: Nikolay Aleksandrov &lt;razor@blackwall.org&gt;
Link: https://lore.kernel.org/r/20240227121128.608110-1-linma@zju.edu.cn
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In the commit d73ef2d69c0d ("rtnetlink: let rtnl_bridge_setlink checks
IFLA_BRIDGE_MODE length"), an adjustment was made to the old loop logic
in the function `rtnl_bridge_setlink` to enable the loop to also check
the length of the IFLA_BRIDGE_MODE attribute. However, this adjustment
removed the `break` statement and led to an error logic of the flags
writing back at the end of this function.

if (have_flags)
    memcpy(nla_data(attr), &amp;flags, sizeof(flags));
    // attr should point to IFLA_BRIDGE_FLAGS NLA !!!

Before the mentioned commit, the `attr` is granted to be IFLA_BRIDGE_FLAGS.
However, this is not necessarily true fow now as the updated loop will let
the attr point to the last NLA, even an invalid NLA which could cause
overflow writes.

This patch introduces a new variable `br_flag` to save the NLA pointer
that points to IFLA_BRIDGE_FLAGS and uses it to resolve the mentioned
error logic.

Fixes: d73ef2d69c0d ("rtnetlink: let rtnl_bridge_setlink checks IFLA_BRIDGE_MODE length")
Signed-off-by: Lin Ma &lt;linma@zju.edu.cn&gt;
Acked-by: Nikolay Aleksandrov &lt;razor@blackwall.org&gt;
Link: https://lore.kernel.org/r/20240227121128.608110-1-linma@zju.edu.cn
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: bridge: confirm multicast packets before passing them up the stack</title>
<updated>2024-02-28T23:22:44+00:00</updated>
<author>
<name>Florian Westphal</name>
<email>fw@strlen.de</email>
</author>
<published>2024-02-27T15:17:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=62e7151ae3eb465e0ab52a20c941ff33bb6332e9'/>
<id>62e7151ae3eb465e0ab52a20c941ff33bb6332e9</id>
<content type='text'>
conntrack nf_confirm logic cannot handle cloned skbs referencing
the same nf_conn entry, which will happen for multicast (broadcast)
frames on bridges.

 Example:
    macvlan0
       |
      br0
     /  \
  ethX    ethY

 ethX (or Y) receives a L2 multicast or broadcast packet containing
 an IP packet, flow is not yet in conntrack table.

 1. skb passes through bridge and fake-ip (br_netfilter)Prerouting.
    -&gt; skb-&gt;_nfct now references a unconfirmed entry
 2. skb is broad/mcast packet. bridge now passes clones out on each bridge
    interface.
 3. skb gets passed up the stack.
 4. In macvlan case, macvlan driver retains clone(s) of the mcast skb
    and schedules a work queue to send them out on the lower devices.

    The clone skb-&gt;_nfct is not a copy, it is the same entry as the
    original skb.  The macvlan rx handler then returns RX_HANDLER_PASS.
 5. Normal conntrack hooks (in NF_INET_LOCAL_IN) confirm the orig skb.

The Macvlan broadcast worker and normal confirm path will race.

This race will not happen if step 2 already confirmed a clone. In that
case later steps perform skb_clone() with skb-&gt;_nfct already confirmed (in
hash table).  This works fine.

But such confirmation won't happen when eb/ip/nftables rules dropped the
packets before they reached the nf_confirm step in postrouting.

Pablo points out that nf_conntrack_bridge doesn't allow use of stateful
nat, so we can safely discard the nf_conn entry and let inet call
conntrack again.

This doesn't work for bridge netfilter: skb could have a nat
transformation. Also bridge nf prevents re-invocation of inet prerouting
via 'sabotage_in' hook.

Work around this problem by explicit confirmation of the entry at LOCAL_IN
time, before upper layer has a chance to clone the unconfirmed entry.

The downside is that this disables NAT and conntrack helpers.

Alternative fix would be to add locking to all code parts that deal with
unconfirmed packets, but even if that could be done in a sane way this
opens up other problems, for example:

-m physdev --physdev-out eth0 -j SNAT --snat-to 1.2.3.4
-m physdev --physdev-out eth1 -j SNAT --snat-to 1.2.3.5

For multicast case, only one of such conflicting mappings will be
created, conntrack only handles 1:1 NAT mappings.

Users should set create a setup that explicitly marks such traffic
NOTRACK (conntrack bypass) to avoid this, but we cannot auto-bypass
them, ruleset might have accept rules for untracked traffic already,
so user-visible behaviour would change.

Suggested-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217777
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>
conntrack nf_confirm logic cannot handle cloned skbs referencing
the same nf_conn entry, which will happen for multicast (broadcast)
frames on bridges.

 Example:
    macvlan0
       |
      br0
     /  \
  ethX    ethY

 ethX (or Y) receives a L2 multicast or broadcast packet containing
 an IP packet, flow is not yet in conntrack table.

 1. skb passes through bridge and fake-ip (br_netfilter)Prerouting.
    -&gt; skb-&gt;_nfct now references a unconfirmed entry
 2. skb is broad/mcast packet. bridge now passes clones out on each bridge
    interface.
 3. skb gets passed up the stack.
 4. In macvlan case, macvlan driver retains clone(s) of the mcast skb
    and schedules a work queue to send them out on the lower devices.

    The clone skb-&gt;_nfct is not a copy, it is the same entry as the
    original skb.  The macvlan rx handler then returns RX_HANDLER_PASS.
 5. Normal conntrack hooks (in NF_INET_LOCAL_IN) confirm the orig skb.

The Macvlan broadcast worker and normal confirm path will race.

This race will not happen if step 2 already confirmed a clone. In that
case later steps perform skb_clone() with skb-&gt;_nfct already confirmed (in
hash table).  This works fine.

But such confirmation won't happen when eb/ip/nftables rules dropped the
packets before they reached the nf_confirm step in postrouting.

Pablo points out that nf_conntrack_bridge doesn't allow use of stateful
nat, so we can safely discard the nf_conn entry and let inet call
conntrack again.

This doesn't work for bridge netfilter: skb could have a nat
transformation. Also bridge nf prevents re-invocation of inet prerouting
via 'sabotage_in' hook.

Work around this problem by explicit confirmation of the entry at LOCAL_IN
time, before upper layer has a chance to clone the unconfirmed entry.

The downside is that this disables NAT and conntrack helpers.

Alternative fix would be to add locking to all code parts that deal with
unconfirmed packets, but even if that could be done in a sane way this
opens up other problems, for example:

-m physdev --physdev-out eth0 -j SNAT --snat-to 1.2.3.4
-m physdev --physdev-out eth1 -j SNAT --snat-to 1.2.3.5

For multicast case, only one of such conflicting mappings will be
created, conntrack only handles 1:1 NAT mappings.

Users should set create a setup that explicitly marks such traffic
NOTRACK (conntrack bypass) to avoid this, but we cannot auto-bypass
them, ruleset might have accept rules for untracked traffic already,
so user-visible behaviour would change.

Suggested-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217777
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>netfilter: nf_tables: allow NFPROTO_INET in nft_(match/target)_validate()</title>
<updated>2024-02-28T22:52:55+00:00</updated>
<author>
<name>Ignat Korchagin</name>
<email>ignat@cloudflare.com</email>
</author>
<published>2024-02-22T10:33:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7e0f122c65912740327e4c54472acaa5f85868cb'/>
<id>7e0f122c65912740327e4c54472acaa5f85868cb</id>
<content type='text'>
Commit d0009effa886 ("netfilter: nf_tables: validate NFPROTO_* family") added
some validation of NFPROTO_* families in the nft_compat module, but it broke
the ability to use legacy iptables modules in dual-stack nftables.

While with legacy iptables one had to independently manage IPv4 and IPv6
tables, with nftables it is possible to have dual-stack tables sharing the
rules. Moreover, it was possible to use rules based on legacy iptables
match/target modules in dual-stack nftables.

As an example, the program from [2] creates an INET dual-stack family table
using an xt_bpf based rule, which looks like the following (the actual output
was generated with a patched nft tool as the current nft tool does not parse
dual stack tables with legacy match rules, so consider it for illustrative
purposes only):

table inet testfw {
  chain input {
    type filter hook prerouting priority filter; policy accept;
    bytecode counter packets 0 bytes 0 accept
  }
}

After d0009effa886 ("netfilter: nf_tables: validate NFPROTO_* family") we get
EOPNOTSUPP for the above program.

Fix this by allowing NFPROTO_INET for nft_(match/target)_validate(), but also
restrict the functions to classic iptables hooks.

Changes in v3:
  * clarify that upstream nft will not display such configuration properly and
    that the output was generated with a patched nft tool
  * remove example program from commit description and link to it instead
  * no code changes otherwise

Changes in v2:
  * restrict nft_(match/target)_validate() to classic iptables hooks
  * rewrite example program to use unmodified libnftnl

Fixes: d0009effa886 ("netfilter: nf_tables: validate NFPROTO_* family")
Link: https://lore.kernel.org/all/Zc1PfoWN38UuFJRI@calendula/T/#mc947262582c90fec044c7a3398cc92fac7afea72 [1]
Link: https://lore.kernel.org/all/20240220145509.53357-1-ignat@cloudflare.com/ [2]
Reported-by: Jordan Griege &lt;jgriege@cloudflare.com&gt;
Signed-off-by: Ignat Korchagin &lt;ignat@cloudflare.com&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>
Commit d0009effa886 ("netfilter: nf_tables: validate NFPROTO_* family") added
some validation of NFPROTO_* families in the nft_compat module, but it broke
the ability to use legacy iptables modules in dual-stack nftables.

While with legacy iptables one had to independently manage IPv4 and IPv6
tables, with nftables it is possible to have dual-stack tables sharing the
rules. Moreover, it was possible to use rules based on legacy iptables
match/target modules in dual-stack nftables.

As an example, the program from [2] creates an INET dual-stack family table
using an xt_bpf based rule, which looks like the following (the actual output
was generated with a patched nft tool as the current nft tool does not parse
dual stack tables with legacy match rules, so consider it for illustrative
purposes only):

table inet testfw {
  chain input {
    type filter hook prerouting priority filter; policy accept;
    bytecode counter packets 0 bytes 0 accept
  }
}

After d0009effa886 ("netfilter: nf_tables: validate NFPROTO_* family") we get
EOPNOTSUPP for the above program.

Fix this by allowing NFPROTO_INET for nft_(match/target)_validate(), but also
restrict the functions to classic iptables hooks.

Changes in v3:
  * clarify that upstream nft will not display such configuration properly and
    that the output was generated with a patched nft tool
  * remove example program from commit description and link to it instead
  * no code changes otherwise

Changes in v2:
  * restrict nft_(match/target)_validate() to classic iptables hooks
  * rewrite example program to use unmodified libnftnl

Fixes: d0009effa886 ("netfilter: nf_tables: validate NFPROTO_* family")
Link: https://lore.kernel.org/all/Zc1PfoWN38UuFJRI@calendula/T/#mc947262582c90fec044c7a3398cc92fac7afea72 [1]
Link: https://lore.kernel.org/all/20240220145509.53357-1-ignat@cloudflare.com/ [2]
Reported-by: Jordan Griege &lt;jgriege@cloudflare.com&gt;
Signed-off-by: Ignat Korchagin &lt;ignat@cloudflare.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
