<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/net/bridge, branch v6.1.151</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>netfilter: br_netfilter: do not check confirmed bit in br_nf_local_in() after confirm</title>
<updated>2025-09-09T16:54:13+00:00</updated>
<author>
<name>Wang Liang</name>
<email>wangliang74@huawei.com</email>
</author>
<published>2025-08-22T03:52:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ccbad4803225eafe0175d3cb19f0d8d73b504a94'/>
<id>ccbad4803225eafe0175d3cb19f0d8d73b504a94</id>
<content type='text'>
[ Upstream commit 479a54ab92087318514c82428a87af2d7af1a576 ]

When send a broadcast packet to a tap device, which was added to a bridge,
br_nf_local_in() is called to confirm the conntrack. If another conntrack
with the same hash value is added to the hash table, which can be
triggered by a normal packet to a non-bridge device, the below warning
may happen.

  ------------[ cut here ]------------
  WARNING: CPU: 1 PID: 96 at net/bridge/br_netfilter_hooks.c:632 br_nf_local_in+0x168/0x200
  CPU: 1 UID: 0 PID: 96 Comm: tap_send Not tainted 6.17.0-rc2-dirty #44 PREEMPT(voluntary)
  RIP: 0010:br_nf_local_in+0x168/0x200
  Call Trace:
   &lt;TASK&gt;
   nf_hook_slow+0x3e/0xf0
   br_pass_frame_up+0x103/0x180
   br_handle_frame_finish+0x2de/0x5b0
   br_nf_hook_thresh+0xc0/0x120
   br_nf_pre_routing_finish+0x168/0x3a0
   br_nf_pre_routing+0x237/0x5e0
   br_handle_frame+0x1ec/0x3c0
   __netif_receive_skb_core+0x225/0x1210
   __netif_receive_skb_one_core+0x37/0xa0
   netif_receive_skb+0x36/0x160
   tun_get_user+0xa54/0x10c0
   tun_chr_write_iter+0x65/0xb0
   vfs_write+0x305/0x410
   ksys_write+0x60/0xd0
   do_syscall_64+0xa4/0x260
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
   &lt;/TASK&gt;
  ---[ end trace 0000000000000000 ]---

To solve the hash conflict, nf_ct_resolve_clash() try to merge the
conntracks, and update skb-&gt;_nfct. However, br_nf_local_in() still use the
old ct from local variable 'nfct' after confirm(), which leads to this
warning.

If confirm() does not insert the conntrack entry and return NF_DROP, the
warning may also occur. There is no need to reserve the WARN_ON_ONCE, just
remove it.

Link: https://lore.kernel.org/netdev/20250820043329.2902014-1-wangliang74@huawei.com/
Fixes: 62e7151ae3eb ("netfilter: bridge: confirm multicast packets before passing them up the stack")
Suggested-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Wang Liang &lt;wangliang74@huawei.com&gt;
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 479a54ab92087318514c82428a87af2d7af1a576 ]

When send a broadcast packet to a tap device, which was added to a bridge,
br_nf_local_in() is called to confirm the conntrack. If another conntrack
with the same hash value is added to the hash table, which can be
triggered by a normal packet to a non-bridge device, the below warning
may happen.

  ------------[ cut here ]------------
  WARNING: CPU: 1 PID: 96 at net/bridge/br_netfilter_hooks.c:632 br_nf_local_in+0x168/0x200
  CPU: 1 UID: 0 PID: 96 Comm: tap_send Not tainted 6.17.0-rc2-dirty #44 PREEMPT(voluntary)
  RIP: 0010:br_nf_local_in+0x168/0x200
  Call Trace:
   &lt;TASK&gt;
   nf_hook_slow+0x3e/0xf0
   br_pass_frame_up+0x103/0x180
   br_handle_frame_finish+0x2de/0x5b0
   br_nf_hook_thresh+0xc0/0x120
   br_nf_pre_routing_finish+0x168/0x3a0
   br_nf_pre_routing+0x237/0x5e0
   br_handle_frame+0x1ec/0x3c0
   __netif_receive_skb_core+0x225/0x1210
   __netif_receive_skb_one_core+0x37/0xa0
   netif_receive_skb+0x36/0x160
   tun_get_user+0xa54/0x10c0
   tun_chr_write_iter+0x65/0xb0
   vfs_write+0x305/0x410
   ksys_write+0x60/0xd0
   do_syscall_64+0xa4/0x260
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
   &lt;/TASK&gt;
  ---[ end trace 0000000000000000 ]---

To solve the hash conflict, nf_ct_resolve_clash() try to merge the
conntracks, and update skb-&gt;_nfct. However, br_nf_local_in() still use the
old ct from local variable 'nfct' after confirm(), which leads to this
warning.

If confirm() does not insert the conntrack entry and return NF_DROP, the
warning may also occur. There is no need to reserve the WARN_ON_ONCE, just
remove it.

Link: https://lore.kernel.org/netdev/20250820043329.2902014-1-wangliang74@huawei.com/
Fixes: 62e7151ae3eb ("netfilter: bridge: confirm multicast packets before passing them up the stack")
Suggested-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Wang Liang &lt;wangliang74@huawei.com&gt;
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: bridge: fix soft lockup in br_multicast_query_expired()</title>
<updated>2025-08-28T14:26:17+00:00</updated>
<author>
<name>Wang Liang</name>
<email>wangliang74@huawei.com</email>
</author>
<published>2025-08-13T02:10:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=43e281fde5e76a866a4d10780c35023f16c0e432'/>
<id>43e281fde5e76a866a4d10780c35023f16c0e432</id>
<content type='text'>
[ Upstream commit d1547bf460baec718b3398365f8de33d25c5f36f ]

When set multicast_query_interval to a large value, the local variable
'time' in br_multicast_send_query() may overflow. If the time is smaller
than jiffies, the timer will expire immediately, and then call mod_timer()
again, which creates a loop and may trigger the following soft lockup
issue.

  watchdog: BUG: soft lockup - CPU#1 stuck for 221s! [rb_consumer:66]
  CPU: 1 UID: 0 PID: 66 Comm: rb_consumer Not tainted 6.16.0+ #259 PREEMPT(none)
  Call Trace:
   &lt;IRQ&gt;
   __netdev_alloc_skb+0x2e/0x3a0
   br_ip6_multicast_alloc_query+0x212/0x1b70
   __br_multicast_send_query+0x376/0xac0
   br_multicast_send_query+0x299/0x510
   br_multicast_query_expired.constprop.0+0x16d/0x1b0
   call_timer_fn+0x3b/0x2a0
   __run_timers+0x619/0x950
   run_timer_softirq+0x11c/0x220
   handle_softirqs+0x18e/0x560
   __irq_exit_rcu+0x158/0x1a0
   sysvec_apic_timer_interrupt+0x76/0x90
   &lt;/IRQ&gt;

This issue can be reproduced with:
  ip link add br0 type bridge
  echo 1 &gt; /sys/class/net/br0/bridge/multicast_querier
  echo 0xffffffffffffffff &gt;
  	/sys/class/net/br0/bridge/multicast_query_interval
  ip link set dev br0 up

The multicast_startup_query_interval can also cause this issue. Similar to
the commit 99b40610956a ("net: bridge: mcast: add and enforce query
interval minimum"), add check for the query interval maximum to fix this
issue.

Link: https://lore.kernel.org/netdev/20250806094941.1285944-1-wangliang74@huawei.com/
Link: https://lore.kernel.org/netdev/20250812091818.542238-1-wangliang74@huawei.com/
Fixes: d902eee43f19 ("bridge: Add multicast count/interval sysfs entries")
Suggested-by: Nikolay Aleksandrov &lt;razor@blackwall.org&gt;
Signed-off-by: Wang Liang &lt;wangliang74@huawei.com&gt;
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Acked-by: Nikolay Aleksandrov &lt;razor@blackwall.org&gt;
Link: https://patch.msgid.link/20250813021054.1643649-1-wangliang74@huawei.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit d1547bf460baec718b3398365f8de33d25c5f36f ]

When set multicast_query_interval to a large value, the local variable
'time' in br_multicast_send_query() may overflow. If the time is smaller
than jiffies, the timer will expire immediately, and then call mod_timer()
again, which creates a loop and may trigger the following soft lockup
issue.

  watchdog: BUG: soft lockup - CPU#1 stuck for 221s! [rb_consumer:66]
  CPU: 1 UID: 0 PID: 66 Comm: rb_consumer Not tainted 6.16.0+ #259 PREEMPT(none)
  Call Trace:
   &lt;IRQ&gt;
   __netdev_alloc_skb+0x2e/0x3a0
   br_ip6_multicast_alloc_query+0x212/0x1b70
   __br_multicast_send_query+0x376/0xac0
   br_multicast_send_query+0x299/0x510
   br_multicast_query_expired.constprop.0+0x16d/0x1b0
   call_timer_fn+0x3b/0x2a0
   __run_timers+0x619/0x950
   run_timer_softirq+0x11c/0x220
   handle_softirqs+0x18e/0x560
   __irq_exit_rcu+0x158/0x1a0
   sysvec_apic_timer_interrupt+0x76/0x90
   &lt;/IRQ&gt;

This issue can be reproduced with:
  ip link add br0 type bridge
  echo 1 &gt; /sys/class/net/br0/bridge/multicast_querier
  echo 0xffffffffffffffff &gt;
  	/sys/class/net/br0/bridge/multicast_query_interval
  ip link set dev br0 up

The multicast_startup_query_interval can also cause this issue. Similar to
the commit 99b40610956a ("net: bridge: mcast: add and enforce query
interval minimum"), add check for the query interval maximum to fix this
issue.

Link: https://lore.kernel.org/netdev/20250806094941.1285944-1-wangliang74@huawei.com/
Link: https://lore.kernel.org/netdev/20250812091818.542238-1-wangliang74@huawei.com/
Fixes: d902eee43f19 ("bridge: Add multicast count/interval sysfs entries")
Suggested-by: Nikolay Aleksandrov &lt;razor@blackwall.org&gt;
Signed-off-by: Wang Liang &lt;wangliang74@huawei.com&gt;
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Acked-by: Nikolay Aleksandrov &lt;razor@blackwall.org&gt;
Link: https://patch.msgid.link/20250813021054.1643649-1-wangliang74@huawei.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: bridge: Do not offload IGMP/MLD messages</title>
<updated>2025-07-24T06:51:53+00:00</updated>
<author>
<name>Joseph Huang</name>
<email>Joseph.Huang@garmin.com</email>
</author>
<published>2025-07-16T15:35:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ca0072c58ffef9f1c8af7f1e921c777f1525a2eb'/>
<id>ca0072c58ffef9f1c8af7f1e921c777f1525a2eb</id>
<content type='text'>
[ Upstream commit 683dc24da8bf199bb7446e445ad7f801c79a550e ]

Do not offload IGMP/MLD messages as it could lead to IGMP/MLD Reports
being unintentionally flooded to Hosts. Instead, let the bridge decide
where to send these IGMP/MLD messages.

Consider the case where the local host is sending out reports in response
to a remote querier like the following:

       mcast-listener-process (IP_ADD_MEMBERSHIP)
          \
          br0
         /   \
      swp1   swp2
        |     |
  QUERIER     SOME-OTHER-HOST

In the above setup, br0 will want to br_forward() reports for
mcast-listener-process's group(s) via swp1 to QUERIER; but since the
source hwdom is 0, the report is eligible for tx offloading, and is
flooded by hardware to both swp1 and swp2, reaching SOME-OTHER-HOST as
well. (Example and illustration provided by Tobias.)

Fixes: 472111920f1c ("net: bridge: switchdev: allow the TX data plane forwarding to be offloaded")
Signed-off-by: Joseph Huang &lt;Joseph.Huang@garmin.com&gt;
Acked-by: Nikolay Aleksandrov &lt;razor@blackwall.org&gt;
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Link: https://patch.msgid.link/20250716153551.1830255-1-Joseph.Huang@garmin.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 683dc24da8bf199bb7446e445ad7f801c79a550e ]

Do not offload IGMP/MLD messages as it could lead to IGMP/MLD Reports
being unintentionally flooded to Hosts. Instead, let the bridge decide
where to send these IGMP/MLD messages.

Consider the case where the local host is sending out reports in response
to a remote querier like the following:

       mcast-listener-process (IP_ADD_MEMBERSHIP)
          \
          br0
         /   \
      swp1   swp2
        |     |
  QUERIER     SOME-OTHER-HOST

In the above setup, br0 will want to br_forward() reports for
mcast-listener-process's group(s) via swp1 to QUERIER; but since the
source hwdom is 0, the report is eligible for tx offloading, and is
flooded by hardware to both swp1 and swp2, reaching SOME-OTHER-HOST as
well. (Example and illustration provided by Tobias.)

Fixes: 472111920f1c ("net: bridge: switchdev: allow the TX data plane forwarding to be offloaded")
Signed-off-by: Joseph Huang &lt;Joseph.Huang@garmin.com&gt;
Acked-by: Nikolay Aleksandrov &lt;razor@blackwall.org&gt;
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Link: https://patch.msgid.link/20250716153551.1830255-1-Joseph.Huang@garmin.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: bridge: mcast: re-implement br_multicast_{enable, disable}_port functions</title>
<updated>2025-06-27T10:07:35+00:00</updated>
<author>
<name>Yong Wang</name>
<email>yongwang@nvidia.com</email>
</author>
<published>2025-04-17T13:43:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c6d16eab122744df698f18b47cf771945cd55066'/>
<id>c6d16eab122744df698f18b47cf771945cd55066</id>
<content type='text'>
[ Upstream commit 4b30ae9adb047dd0a7982975ec3933c529537026 ]

When a bridge port STP state is changed from BLOCKING/DISABLED to
FORWARDING, the port's igmp query timer will NOT re-arm itself if the
bridge has been configured as per-VLAN multicast snooping.

Solve this by choosing the correct multicast context(s) to enable/disable
port multicast based on whether per-VLAN multicast snooping is enabled or
not, i.e. using per-{port, VLAN} context in case of per-VLAN multicast
snooping by re-implementing br_multicast_enable_port() and
br_multicast_disable_port() functions.

Before the patch, the IGMP query does not happen in the last step of the
following test sequence, i.e. no growth for tx counter:
 # ip link add name br1 up type bridge vlan_filtering 1 mcast_snooping 1 mcast_vlan_snooping 1 mcast_querier 1 mcast_stats_enabled 1
 # bridge vlan global set vid 1 dev br1 mcast_snooping 1 mcast_querier 1 mcast_query_interval 100 mcast_startup_query_count 0
 # ip link add name swp1 up master br1 type dummy
 # bridge link set dev swp1 state 0
 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]'
1
 # sleep 1
 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]'
1
 # bridge link set dev swp1 state 3
 # sleep 2
 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]'
1

After the patch, the IGMP query happens in the last step of the test:
 # ip link add name br1 up type bridge vlan_filtering 1 mcast_snooping 1 mcast_vlan_snooping 1 mcast_querier 1 mcast_stats_enabled 1
 # bridge vlan global set vid 1 dev br1 mcast_snooping 1 mcast_querier 1 mcast_query_interval 100 mcast_startup_query_count 0
 # ip link add name swp1 up master br1 type dummy
 # bridge link set dev swp1 state 0
 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]'
1
 # sleep 1
 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]'
1
 # bridge link set dev swp1 state 3
 # sleep 2
 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]'
3

Signed-off-by: Yong Wang &lt;yongwang@nvidia.com&gt;
Reviewed-by: Andy Roulin &lt;aroulin@nvidia.com&gt;
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Signed-off-by: Petr Machata &lt;petrm@nvidia.com&gt;
Acked-by: Nikolay Aleksandrov &lt;razor@blackwall.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 4b30ae9adb047dd0a7982975ec3933c529537026 ]

When a bridge port STP state is changed from BLOCKING/DISABLED to
FORWARDING, the port's igmp query timer will NOT re-arm itself if the
bridge has been configured as per-VLAN multicast snooping.

Solve this by choosing the correct multicast context(s) to enable/disable
port multicast based on whether per-VLAN multicast snooping is enabled or
not, i.e. using per-{port, VLAN} context in case of per-VLAN multicast
snooping by re-implementing br_multicast_enable_port() and
br_multicast_disable_port() functions.

Before the patch, the IGMP query does not happen in the last step of the
following test sequence, i.e. no growth for tx counter:
 # ip link add name br1 up type bridge vlan_filtering 1 mcast_snooping 1 mcast_vlan_snooping 1 mcast_querier 1 mcast_stats_enabled 1
 # bridge vlan global set vid 1 dev br1 mcast_snooping 1 mcast_querier 1 mcast_query_interval 100 mcast_startup_query_count 0
 # ip link add name swp1 up master br1 type dummy
 # bridge link set dev swp1 state 0
 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]'
1
 # sleep 1
 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]'
1
 # bridge link set dev swp1 state 3
 # sleep 2
 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]'
1

After the patch, the IGMP query happens in the last step of the test:
 # ip link add name br1 up type bridge vlan_filtering 1 mcast_snooping 1 mcast_vlan_snooping 1 mcast_querier 1 mcast_stats_enabled 1
 # bridge vlan global set vid 1 dev br1 mcast_snooping 1 mcast_querier 1 mcast_query_interval 100 mcast_startup_query_count 0
 # ip link add name swp1 up master br1 type dummy
 # bridge link set dev swp1 state 0
 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]'
1
 # sleep 1
 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]'
1
 # bridge link set dev swp1 state 3
 # sleep 2
 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]'
3

Signed-off-by: Yong Wang &lt;yongwang@nvidia.com&gt;
Reviewed-by: Andy Roulin &lt;aroulin@nvidia.com&gt;
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Signed-off-by: Petr Machata &lt;petrm@nvidia.com&gt;
Acked-by: Nikolay Aleksandrov &lt;razor@blackwall.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: bridge: mcast: update multicast contex when vlan state is changed</title>
<updated>2025-06-27T10:07:34+00:00</updated>
<author>
<name>Yong Wang</name>
<email>yongwang@nvidia.com</email>
</author>
<published>2025-04-17T13:43:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c5327af6e0ed5a58023d49f7211723cb6f5c9e94'/>
<id>c5327af6e0ed5a58023d49f7211723cb6f5c9e94</id>
<content type='text'>
[ Upstream commit 6c131043eaf1be2a6cc2d228f92ceb626fbcc0f3 ]

When the vlan STP state is changed, which could be manipulated by
"bridge vlan" commands, similar to port STP state, this also impacts
multicast behaviors such as igmp query. In the scenario of per-VLAN
snooping, there's a need to update the corresponding multicast context
to re-arm the port query timer when vlan state becomes "forwarding" etc.

Update br_vlan_set_state() function to enable vlan multicast context
in such scenario.

Before the patch, the IGMP query does not happen in the last step of the
following test sequence, i.e. no growth for tx counter:
 # ip link add name br1 up type bridge vlan_filtering 1 mcast_snooping 1 mcast_vlan_snooping 1 mcast_querier 1 mcast_stats_enabled 1
 # bridge vlan global set vid 1 dev br1 mcast_snooping 1 mcast_querier 1 mcast_query_interval 100 mcast_startup_query_count 0
 # ip link add name swp1 up master br1 type dummy
 # sleep 1
 # bridge vlan set vid 1 dev swp1 state 4
 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]'
1
 # sleep 1
 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]'
1
 # bridge vlan set vid 1 dev swp1 state 3
 # sleep 2
 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]'
1

After the patch, the IGMP query happens in the last step of the test:
 # ip link add name br1 up type bridge vlan_filtering 1 mcast_snooping 1 mcast_vlan_snooping 1 mcast_querier 1 mcast_stats_enabled 1
 # bridge vlan global set vid 1 dev br1 mcast_snooping 1 mcast_querier 1 mcast_query_interval 100 mcast_startup_query_count 0
 # ip link add name swp1 up master br1 type dummy
 # sleep 1
 # bridge vlan set vid 1 dev swp1 state 4
 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]'
1
 # sleep 1
 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]'
1
 # bridge vlan set vid 1 dev swp1 state 3
 # sleep 2
 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]'
3

Signed-off-by: Yong Wang &lt;yongwang@nvidia.com&gt;
Reviewed-by: Andy Roulin &lt;aroulin@nvidia.com&gt;
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Signed-off-by: Petr Machata &lt;petrm@nvidia.com&gt;
Acked-by: Nikolay Aleksandrov &lt;razor@blackwall.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 6c131043eaf1be2a6cc2d228f92ceb626fbcc0f3 ]

When the vlan STP state is changed, which could be manipulated by
"bridge vlan" commands, similar to port STP state, this also impacts
multicast behaviors such as igmp query. In the scenario of per-VLAN
snooping, there's a need to update the corresponding multicast context
to re-arm the port query timer when vlan state becomes "forwarding" etc.

Update br_vlan_set_state() function to enable vlan multicast context
in such scenario.

Before the patch, the IGMP query does not happen in the last step of the
following test sequence, i.e. no growth for tx counter:
 # ip link add name br1 up type bridge vlan_filtering 1 mcast_snooping 1 mcast_vlan_snooping 1 mcast_querier 1 mcast_stats_enabled 1
 # bridge vlan global set vid 1 dev br1 mcast_snooping 1 mcast_querier 1 mcast_query_interval 100 mcast_startup_query_count 0
 # ip link add name swp1 up master br1 type dummy
 # sleep 1
 # bridge vlan set vid 1 dev swp1 state 4
 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]'
1
 # sleep 1
 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]'
1
 # bridge vlan set vid 1 dev swp1 state 3
 # sleep 2
 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]'
1

After the patch, the IGMP query happens in the last step of the test:
 # ip link add name br1 up type bridge vlan_filtering 1 mcast_snooping 1 mcast_vlan_snooping 1 mcast_querier 1 mcast_stats_enabled 1
 # bridge vlan global set vid 1 dev br1 mcast_snooping 1 mcast_querier 1 mcast_query_interval 100 mcast_startup_query_count 0
 # ip link add name swp1 up master br1 type dummy
 # sleep 1
 # bridge vlan set vid 1 dev swp1 state 4
 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]'
1
 # sleep 1
 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]'
1
 # bridge vlan set vid 1 dev swp1 state 3
 # sleep 2
 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]'
3

Signed-off-by: Yong Wang &lt;yongwang@nvidia.com&gt;
Reviewed-by: Andy Roulin &lt;aroulin@nvidia.com&gt;
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Signed-off-by: Petr Machata &lt;petrm@nvidia.com&gt;
Acked-by: Nikolay Aleksandrov &lt;razor@blackwall.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: bridge: Move specific fragmented packet to slow_path instead of dropping it</title>
<updated>2025-06-27T10:07:10+00:00</updated>
<author>
<name>Huajian Yang</name>
<email>huajianyang@asrmicro.com</email>
</author>
<published>2025-04-17T09:29:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=260cbb00910f96f83874ca846285f71ae1dff097'/>
<id>260cbb00910f96f83874ca846285f71ae1dff097</id>
<content type='text'>
[ Upstream commit aa04c6f45b9224b949aa35d4fa5f8d0ba07b23d4 ]

The config NF_CONNTRACK_BRIDGE will change the bridge forwarding for
fragmented packets.

The original bridge does not know that it is a fragmented packet and
forwards it directly, after NF_CONNTRACK_BRIDGE is enabled, function
nf_br_ip_fragment and br_ip6_fragment will check the headroom.

In original br_forward, insufficient headroom of skb may indeed exist,
but there's still a way to save the skb in the device driver after
dev_queue_xmit.So droping the skb will change the original bridge
forwarding in some cases.

Fixes: 3c171f496ef5 ("netfilter: bridge: add connection tracking system")
Signed-off-by: Huajian Yang &lt;huajianyang@asrmicro.com&gt;
Reviewed-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit aa04c6f45b9224b949aa35d4fa5f8d0ba07b23d4 ]

The config NF_CONNTRACK_BRIDGE will change the bridge forwarding for
fragmented packets.

The original bridge does not know that it is a fragmented packet and
forwards it directly, after NF_CONNTRACK_BRIDGE is enabled, function
nf_br_ip_fragment and br_ip6_fragment will check the headroom.

In original br_forward, insufficient headroom of skb may indeed exist,
but there's still a way to save the skb in the device driver after
dev_queue_xmit.So droping the skb will change the original bridge
forwarding in some cases.

Fixes: 3c171f496ef5 ("netfilter: bridge: add connection tracking system")
Signed-off-by: Huajian Yang &lt;huajianyang@asrmicro.com&gt;
Reviewed-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bridge: netfilter: Fix forwarding of fragmented packets</title>
<updated>2025-06-04T12:40:19+00:00</updated>
<author>
<name>Ido Schimmel</name>
<email>idosch@nvidia.com</email>
</author>
<published>2025-05-15T08:48:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2cee71a1a2738f39b09ddaec24d434572ce2c91a'/>
<id>2cee71a1a2738f39b09ddaec24d434572ce2c91a</id>
<content type='text'>
[ Upstream commit 91b6dbced0ef1d680afdd69b14fc83d50ebafaf3 ]

When netfilter defrag hooks are loaded (due to the presence of conntrack
rules, for example), fragmented packets entering the bridge will be
defragged by the bridge's pre-routing hook (br_nf_pre_routing() -&gt;
ipv4_conntrack_defrag()).

Later on, in the bridge's post-routing hook, the defragged packet will
be fragmented again. If the size of the largest fragment is larger than
what the kernel has determined as the destination MTU (using
ip_skb_dst_mtu()), the defragged packet will be dropped.

Before commit ac6627a28dbf ("net: ipv4: Consolidate ipv4_mtu and
ip_dst_mtu_maybe_forward"), ip_skb_dst_mtu() would return dst_mtu() as
the destination MTU. Assuming the dst entry attached to the packet is
the bridge's fake rtable one, this would simply be the bridge's MTU (see
fake_mtu()).

However, after above mentioned commit, ip_skb_dst_mtu() ends up
returning the route's MTU stored in the dst entry's metrics. Ideally, in
case the dst entry is the bridge's fake rtable one, this should be the
bridge's MTU as the bridge takes care of updating this metric when its
MTU changes (see br_change_mtu()).

Unfortunately, the last operation is a no-op given the metrics attached
to the fake rtable entry are marked as read-only. Therefore,
ip_skb_dst_mtu() ends up returning 1500 (the initial MTU value) and
defragged packets are dropped during fragmentation when dealing with
large fragments and high MTU (e.g., 9k).

Fix by moving the fake rtable entry's metrics to be per-bridge (in a
similar fashion to the fake rtable entry itself) and marking them as
writable, thereby allowing MTU changes to be reflected.

Fixes: 62fa8a846d7d ("net: Implement read-only protection and COW'ing of metrics.")
Fixes: 33eb9873a283 ("bridge: initialize fake_rtable metrics")
Reported-by: Venkat Venkatsubra &lt;venkat.x.venkatsubra@oracle.com&gt;
Closes: https://lore.kernel.org/netdev/PH0PR10MB4504888284FF4CBA648197D0ACB82@PH0PR10MB4504.namprd10.prod.outlook.com/
Tested-by: Venkat Venkatsubra &lt;venkat.x.venkatsubra@oracle.com&gt;
Signed-off-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Acked-by: Nikolay Aleksandrov &lt;razor@blackwall.org&gt;
Link: https://patch.msgid.link/20250515084848.727706-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 91b6dbced0ef1d680afdd69b14fc83d50ebafaf3 ]

When netfilter defrag hooks are loaded (due to the presence of conntrack
rules, for example), fragmented packets entering the bridge will be
defragged by the bridge's pre-routing hook (br_nf_pre_routing() -&gt;
ipv4_conntrack_defrag()).

Later on, in the bridge's post-routing hook, the defragged packet will
be fragmented again. If the size of the largest fragment is larger than
what the kernel has determined as the destination MTU (using
ip_skb_dst_mtu()), the defragged packet will be dropped.

Before commit ac6627a28dbf ("net: ipv4: Consolidate ipv4_mtu and
ip_dst_mtu_maybe_forward"), ip_skb_dst_mtu() would return dst_mtu() as
the destination MTU. Assuming the dst entry attached to the packet is
the bridge's fake rtable one, this would simply be the bridge's MTU (see
fake_mtu()).

However, after above mentioned commit, ip_skb_dst_mtu() ends up
returning the route's MTU stored in the dst entry's metrics. Ideally, in
case the dst entry is the bridge's fake rtable one, this should be the
bridge's MTU as the bridge takes care of updating this metric when its
MTU changes (see br_change_mtu()).

Unfortunately, the last operation is a no-op given the metrics attached
to the fake rtable entry are marked as read-only. Therefore,
ip_skb_dst_mtu() ends up returning 1500 (the initial MTU value) and
defragged packets are dropped during fragmentation when dealing with
large fragments and high MTU (e.g., 9k).

Fix by moving the fake rtable entry's metrics to be per-bridge (in a
similar fashion to the fake rtable entry itself) and marking them as
writable, thereby allowing MTU changes to be reflected.

Fixes: 62fa8a846d7d ("net: Implement read-only protection and COW'ing of metrics.")
Fixes: 33eb9873a283 ("bridge: initialize fake_rtable metrics")
Reported-by: Venkat Venkatsubra &lt;venkat.x.venkatsubra@oracle.com&gt;
Closes: https://lore.kernel.org/netdev/PH0PR10MB4504888284FF4CBA648197D0ACB82@PH0PR10MB4504.namprd10.prod.outlook.com/
Tested-by: Venkat Venkatsubra &lt;venkat.x.venkatsubra@oracle.com&gt;
Signed-off-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Acked-by: Nikolay Aleksandrov &lt;razor@blackwall.org&gt;
Link: https://patch.msgid.link/20250515084848.727706-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: bridge: switchdev: do not notify new brentries as changed</title>
<updated>2025-04-25T08:43:50+00:00</updated>
<author>
<name>Jonas Gorski</name>
<email>jonas.gorski@gmail.com</email>
</author>
<published>2025-04-14T20:00:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f06b5b4225b869a881e930bf24303adefb98aa78'/>
<id>f06b5b4225b869a881e930bf24303adefb98aa78</id>
<content type='text'>
[ Upstream commit eb25de13bd9cf025413a04f25e715d0e99847e30 ]

When adding a bridge vlan that is pvid or untagged after the vlan has
already been added to any other switchdev backed port, the vlan change
will be propagated as changed, since the flags change.

This causes the vlan to not be added to the hardware for DSA switches,
since the DSA handler ignores any vlans for the CPU or DSA ports that
are changed.

E.g. the following order of operations would work:

$ ip link add swbridge type bridge vlan_filtering 1 vlan_default_pvid 0
$ ip link set lan1 master swbridge
$ bridge vlan add dev swbridge vid 1 pvid untagged self
$ bridge vlan add dev lan1 vid 1 pvid untagged

but this order would break:

$ ip link add swbridge type bridge vlan_filtering 1 vlan_default_pvid 0
$ ip link set lan1 master swbridge
$ bridge vlan add dev lan1 vid 1 pvid untagged
$ bridge vlan add dev swbridge vid 1 pvid untagged self

Additionally, the vlan on the bridge itself would become undeletable:

$ bridge vlan
port              vlan-id
lan1              1 PVID Egress Untagged
swbridge          1 PVID Egress Untagged
$ bridge vlan del dev swbridge vid 1 self
$ bridge vlan
port              vlan-id
lan1              1 PVID Egress Untagged
swbridge          1 Egress Untagged

since the vlan was never added to DSA's vlan list, so deleting it will
cause an error, causing the bridge code to not remove it.

Fix this by checking if flags changed only for vlans that are already
brentry and pass changed as false for those that become brentries, as
these are a new vlan (member) from the switchdev point of view.

Since *changed is set to true for becomes_brentry = true regardless of
would_change's value, this will not change any rtnetlink notification
delivery, just the value passed on to switchdev in vlan-&gt;changed.

Fixes: 8d23a54f5bee ("net: bridge: switchdev: differentiate new VLANs from changed ones")
Reviewed-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Signed-off-by: Jonas Gorski &lt;jonas.gorski@gmail.com&gt;
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Acked-by: Nikolay Aleksandrov &lt;razor@blackwall.org&gt;
Link: https://patch.msgid.link/20250414200020.192715-1-jonas.gorski@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit eb25de13bd9cf025413a04f25e715d0e99847e30 ]

When adding a bridge vlan that is pvid or untagged after the vlan has
already been added to any other switchdev backed port, the vlan change
will be propagated as changed, since the flags change.

This causes the vlan to not be added to the hardware for DSA switches,
since the DSA handler ignores any vlans for the CPU or DSA ports that
are changed.

E.g. the following order of operations would work:

$ ip link add swbridge type bridge vlan_filtering 1 vlan_default_pvid 0
$ ip link set lan1 master swbridge
$ bridge vlan add dev swbridge vid 1 pvid untagged self
$ bridge vlan add dev lan1 vid 1 pvid untagged

but this order would break:

$ ip link add swbridge type bridge vlan_filtering 1 vlan_default_pvid 0
$ ip link set lan1 master swbridge
$ bridge vlan add dev lan1 vid 1 pvid untagged
$ bridge vlan add dev swbridge vid 1 pvid untagged self

Additionally, the vlan on the bridge itself would become undeletable:

$ bridge vlan
port              vlan-id
lan1              1 PVID Egress Untagged
swbridge          1 PVID Egress Untagged
$ bridge vlan del dev swbridge vid 1 self
$ bridge vlan
port              vlan-id
lan1              1 PVID Egress Untagged
swbridge          1 Egress Untagged

since the vlan was never added to DSA's vlan list, so deleting it will
cause an error, causing the bridge code to not remove it.

Fix this by checking if flags changed only for vlans that are already
brentry and pass changed as false for those that become brentries, as
these are a new vlan (member) from the switchdev point of view.

Since *changed is set to true for becomes_brentry = true regardless of
would_change's value, this will not change any rtnetlink notification
delivery, just the value passed on to switchdev in vlan-&gt;changed.

Fixes: 8d23a54f5bee ("net: bridge: switchdev: differentiate new VLANs from changed ones")
Reviewed-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Signed-off-by: Jonas Gorski &lt;jonas.gorski@gmail.com&gt;
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Acked-by: Nikolay Aleksandrov &lt;razor@blackwall.org&gt;
Link: https://patch.msgid.link/20250414200020.192715-1-jonas.gorski@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipv4: Convert ip_route_input() to dscp_t.</title>
<updated>2025-03-07T15:56:44+00:00</updated>
<author>
<name>Guillaume Nault</name>
<email>gnault@redhat.com</email>
</author>
<published>2024-10-01T19:28:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3e8520bca50199b3e5fcc4c569bb7b7033ba7d8a'/>
<id>3e8520bca50199b3e5fcc4c569bb7b7033ba7d8a</id>
<content type='text'>
[ Upstream commit 7e863e5db6185b1add0df4cb01b31a4ed1c4b738 ]

Pass a dscp_t variable to ip_route_input(), instead of a plain u8, to
prevent accidental setting of ECN bits in -&gt;flowi4_tos.

Callers of ip_route_input() to consider are:

  * input_action_end_dx4_finish() and input_action_end_dt4() in
    net/ipv6/seg6_local.c. These functions set the tos parameter to 0,
    which is already a valid dscp_t value, so they don't need to be
    adjusted for the new prototype.

  * icmp_route_lookup(), which already has a dscp_t variable to pass as
    parameter. We just need to remove the inet_dscp_to_dsfield()
    conversion.

  * br_nf_pre_routing_finish(), ip_options_rcv_srr() and ip4ip6_err(),
    which get the DSCP directly from IPv4 headers. Define a helper to
    read the .tos field of struct iphdr as dscp_t, so that these
    function don't have to do the conversion manually.

While there, declare *iph as const in br_nf_pre_routing_finish(),
declare its local variables in reverse-christmas-tree order and move
the "err = ip_route_input()" assignment out of the conditional to avoid
checkpatch warning.

Signed-off-by: Guillaume Nault &lt;gnault@redhat.com&gt;
Reviewed-by: David Ahern &lt;dsahern@kernel.org&gt;
Link: https://patch.msgid.link/e9d40781d64d3d69f4c79ac8a008b8d67a033e8d.1727807926.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Stable-dep-of: 27843ce6ba3d ("ipvlan: ensure network headers are in skb linear part")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 7e863e5db6185b1add0df4cb01b31a4ed1c4b738 ]

Pass a dscp_t variable to ip_route_input(), instead of a plain u8, to
prevent accidental setting of ECN bits in -&gt;flowi4_tos.

Callers of ip_route_input() to consider are:

  * input_action_end_dx4_finish() and input_action_end_dt4() in
    net/ipv6/seg6_local.c. These functions set the tos parameter to 0,
    which is already a valid dscp_t value, so they don't need to be
    adjusted for the new prototype.

  * icmp_route_lookup(), which already has a dscp_t variable to pass as
    parameter. We just need to remove the inet_dscp_to_dsfield()
    conversion.

  * br_nf_pre_routing_finish(), ip_options_rcv_srr() and ip4ip6_err(),
    which get the DSCP directly from IPv4 headers. Define a helper to
    read the .tos field of struct iphdr as dscp_t, so that these
    function don't have to do the conversion manually.

While there, declare *iph as const in br_nf_pre_routing_finish(),
declare its local variables in reverse-christmas-tree order and move
the "err = ip_route_input()" assignment out of the conditional to avoid
checkpatch warning.

Signed-off-by: Guillaume Nault &lt;gnault@redhat.com&gt;
Reviewed-by: David Ahern &lt;dsahern@kernel.org&gt;
Link: https://patch.msgid.link/e9d40781d64d3d69f4c79ac8a008b8d67a033e8d.1727807926.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Stable-dep-of: 27843ce6ba3d ("ipvlan: ensure network headers are in skb linear part")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: br_netfilter: fix panic with metadata_dst skb</title>
<updated>2024-10-17T13:22:19+00:00</updated>
<author>
<name>Andy Roulin</name>
<email>aroulin@nvidia.com</email>
</author>
<published>2024-10-01T15:43:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=78ed917133b118661e1fe62d4a85d5d428ee9568'/>
<id>78ed917133b118661e1fe62d4a85d5d428ee9568</id>
<content type='text'>
[ Upstream commit f9ff7665cd128012868098bbd07e28993e314fdb ]

Fix a kernel panic in the br_netfilter module when sending untagged
traffic via a VxLAN device.
This happens during the check for fragmentation in br_nf_dev_queue_xmit.

It is dependent on:
1) the br_netfilter module being loaded;
2) net.bridge.bridge-nf-call-iptables set to 1;
3) a bridge with a VxLAN (single-vxlan-device) netdevice as a bridge port;
4) untagged frames with size higher than the VxLAN MTU forwarded/flooded

When forwarding the untagged packet to the VxLAN bridge port, before
the netfilter hooks are called, br_handle_egress_vlan_tunnel is called and
changes the skb_dst to the tunnel dst. The tunnel_dst is a metadata type
of dst, i.e., skb_valid_dst(skb) is false, and metadata-&gt;dst.dev is NULL.

Then in the br_netfilter hooks, in br_nf_dev_queue_xmit, there's a check
for frames that needs to be fragmented: frames with higher MTU than the
VxLAN device end up calling br_nf_ip_fragment, which in turns call
ip_skb_dst_mtu.

The ip_dst_mtu tries to use the skb_dst(skb) as if it was a valid dst
with valid dst-&gt;dev, thus the crash.

This case was never supported in the first place, so drop the packet
instead.

PING 10.0.0.2 (10.0.0.2) from 0.0.0.0 h1-eth0: 2000(2028) bytes of data.
[  176.291791] Unable to handle kernel NULL pointer dereference at
virtual address 0000000000000110
[  176.292101] Mem abort info:
[  176.292184]   ESR = 0x0000000096000004
[  176.292322]   EC = 0x25: DABT (current EL), IL = 32 bits
[  176.292530]   SET = 0, FnV = 0
[  176.292709]   EA = 0, S1PTW = 0
[  176.292862]   FSC = 0x04: level 0 translation fault
[  176.293013] Data abort info:
[  176.293104]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[  176.293488]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[  176.293787]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[  176.293995] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000043ef5000
[  176.294166] [0000000000000110] pgd=0000000000000000,
p4d=0000000000000000
[  176.294827] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
[  176.295252] Modules linked in: vxlan ip6_udp_tunnel udp_tunnel veth
br_netfilter bridge stp llc ipv6 crct10dif_ce
[  176.295923] CPU: 0 PID: 188 Comm: ping Not tainted
6.8.0-rc3-g5b3fbd61b9d1 #2
[  176.296314] Hardware name: linux,dummy-virt (DT)
[  176.296535] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS
BTYPE=--)
[  176.296808] pc : br_nf_dev_queue_xmit+0x390/0x4ec [br_netfilter]
[  176.297382] lr : br_nf_dev_queue_xmit+0x2ac/0x4ec [br_netfilter]
[  176.297636] sp : ffff800080003630
[  176.297743] x29: ffff800080003630 x28: 0000000000000008 x27:
ffff6828c49ad9f8
[  176.298093] x26: ffff6828c49ad000 x25: 0000000000000000 x24:
00000000000003e8
[  176.298430] x23: 0000000000000000 x22: ffff6828c4960b40 x21:
ffff6828c3b16d28
[  176.298652] x20: ffff6828c3167048 x19: ffff6828c3b16d00 x18:
0000000000000014
[  176.298926] x17: ffffb0476322f000 x16: ffffb7e164023730 x15:
0000000095744632
[  176.299296] x14: ffff6828c3f1c880 x13: 0000000000000002 x12:
ffffb7e137926a70
[  176.299574] x11: 0000000000000001 x10: ffff6828c3f1c898 x9 :
0000000000000000
[  176.300049] x8 : ffff6828c49bf070 x7 : 0008460f18d5f20e x6 :
f20e0100bebafeca
[  176.300302] x5 : ffff6828c7f918fe x4 : ffff6828c49bf070 x3 :
0000000000000000
[  176.300586] x2 : 0000000000000000 x1 : ffff6828c3c7ad00 x0 :
ffff6828c7f918f0
[  176.300889] Call trace:
[  176.301123]  br_nf_dev_queue_xmit+0x390/0x4ec [br_netfilter]
[  176.301411]  br_nf_post_routing+0x2a8/0x3e4 [br_netfilter]
[  176.301703]  nf_hook_slow+0x48/0x124
[  176.302060]  br_forward_finish+0xc8/0xe8 [bridge]
[  176.302371]  br_nf_hook_thresh+0x124/0x134 [br_netfilter]
[  176.302605]  br_nf_forward_finish+0x118/0x22c [br_netfilter]
[  176.302824]  br_nf_forward_ip.part.0+0x264/0x290 [br_netfilter]
[  176.303136]  br_nf_forward+0x2b8/0x4e0 [br_netfilter]
[  176.303359]  nf_hook_slow+0x48/0x124
[  176.303803]  __br_forward+0xc4/0x194 [bridge]
[  176.304013]  br_flood+0xd4/0x168 [bridge]
[  176.304300]  br_handle_frame_finish+0x1d4/0x5c4 [bridge]
[  176.304536]  br_nf_hook_thresh+0x124/0x134 [br_netfilter]
[  176.304978]  br_nf_pre_routing_finish+0x29c/0x494 [br_netfilter]
[  176.305188]  br_nf_pre_routing+0x250/0x524 [br_netfilter]
[  176.305428]  br_handle_frame+0x244/0x3cc [bridge]
[  176.305695]  __netif_receive_skb_core.constprop.0+0x33c/0xecc
[  176.306080]  __netif_receive_skb_one_core+0x40/0x8c
[  176.306197]  __netif_receive_skb+0x18/0x64
[  176.306369]  process_backlog+0x80/0x124
[  176.306540]  __napi_poll+0x38/0x17c
[  176.306636]  net_rx_action+0x124/0x26c
[  176.306758]  __do_softirq+0x100/0x26c
[  176.307051]  ____do_softirq+0x10/0x1c
[  176.307162]  call_on_irq_stack+0x24/0x4c
[  176.307289]  do_softirq_own_stack+0x1c/0x2c
[  176.307396]  do_softirq+0x54/0x6c
[  176.307485]  __local_bh_enable_ip+0x8c/0x98
[  176.307637]  __dev_queue_xmit+0x22c/0xd28
[  176.307775]  neigh_resolve_output+0xf4/0x1a0
[  176.308018]  ip_finish_output2+0x1c8/0x628
[  176.308137]  ip_do_fragment+0x5b4/0x658
[  176.308279]  ip_fragment.constprop.0+0x48/0xec
[  176.308420]  __ip_finish_output+0xa4/0x254
[  176.308593]  ip_finish_output+0x34/0x130
[  176.308814]  ip_output+0x6c/0x108
[  176.308929]  ip_send_skb+0x50/0xf0
[  176.309095]  ip_push_pending_frames+0x30/0x54
[  176.309254]  raw_sendmsg+0x758/0xaec
[  176.309568]  inet_sendmsg+0x44/0x70
[  176.309667]  __sys_sendto+0x110/0x178
[  176.309758]  __arm64_sys_sendto+0x28/0x38
[  176.309918]  invoke_syscall+0x48/0x110
[  176.310211]  el0_svc_common.constprop.0+0x40/0xe0
[  176.310353]  do_el0_svc+0x1c/0x28
[  176.310434]  el0_svc+0x34/0xb4
[  176.310551]  el0t_64_sync_handler+0x120/0x12c
[  176.310690]  el0t_64_sync+0x190/0x194
[  176.311066] Code: f9402e61 79402aa2 927ff821 f9400023 (f9408860)
[  176.315743] ---[ end trace 0000000000000000 ]---
[  176.316060] Kernel panic - not syncing: Oops: Fatal exception in
interrupt
[  176.316371] Kernel Offset: 0x37e0e3000000 from 0xffff800080000000
[  176.316564] PHYS_OFFSET: 0xffff97d780000000
[  176.316782] CPU features: 0x0,88000203,3c020000,0100421b
[  176.317210] Memory Limit: none
[  176.317527] ---[ end Kernel panic - not syncing: Oops: Fatal
Exception in interrupt ]---\

Fixes: 11538d039ac6 ("bridge: vlan dst_metadata hooks in ingress and egress paths")
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Signed-off-by: Andy Roulin &lt;aroulin@nvidia.com&gt;
Acked-by: Nikolay Aleksandrov &lt;razor@blackwall.org&gt;
Link: https://patch.msgid.link/20241001154400.22787-2-aroulin@nvidia.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit f9ff7665cd128012868098bbd07e28993e314fdb ]

Fix a kernel panic in the br_netfilter module when sending untagged
traffic via a VxLAN device.
This happens during the check for fragmentation in br_nf_dev_queue_xmit.

It is dependent on:
1) the br_netfilter module being loaded;
2) net.bridge.bridge-nf-call-iptables set to 1;
3) a bridge with a VxLAN (single-vxlan-device) netdevice as a bridge port;
4) untagged frames with size higher than the VxLAN MTU forwarded/flooded

When forwarding the untagged packet to the VxLAN bridge port, before
the netfilter hooks are called, br_handle_egress_vlan_tunnel is called and
changes the skb_dst to the tunnel dst. The tunnel_dst is a metadata type
of dst, i.e., skb_valid_dst(skb) is false, and metadata-&gt;dst.dev is NULL.

Then in the br_netfilter hooks, in br_nf_dev_queue_xmit, there's a check
for frames that needs to be fragmented: frames with higher MTU than the
VxLAN device end up calling br_nf_ip_fragment, which in turns call
ip_skb_dst_mtu.

The ip_dst_mtu tries to use the skb_dst(skb) as if it was a valid dst
with valid dst-&gt;dev, thus the crash.

This case was never supported in the first place, so drop the packet
instead.

PING 10.0.0.2 (10.0.0.2) from 0.0.0.0 h1-eth0: 2000(2028) bytes of data.
[  176.291791] Unable to handle kernel NULL pointer dereference at
virtual address 0000000000000110
[  176.292101] Mem abort info:
[  176.292184]   ESR = 0x0000000096000004
[  176.292322]   EC = 0x25: DABT (current EL), IL = 32 bits
[  176.292530]   SET = 0, FnV = 0
[  176.292709]   EA = 0, S1PTW = 0
[  176.292862]   FSC = 0x04: level 0 translation fault
[  176.293013] Data abort info:
[  176.293104]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[  176.293488]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[  176.293787]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[  176.293995] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000043ef5000
[  176.294166] [0000000000000110] pgd=0000000000000000,
p4d=0000000000000000
[  176.294827] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
[  176.295252] Modules linked in: vxlan ip6_udp_tunnel udp_tunnel veth
br_netfilter bridge stp llc ipv6 crct10dif_ce
[  176.295923] CPU: 0 PID: 188 Comm: ping Not tainted
6.8.0-rc3-g5b3fbd61b9d1 #2
[  176.296314] Hardware name: linux,dummy-virt (DT)
[  176.296535] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS
BTYPE=--)
[  176.296808] pc : br_nf_dev_queue_xmit+0x390/0x4ec [br_netfilter]
[  176.297382] lr : br_nf_dev_queue_xmit+0x2ac/0x4ec [br_netfilter]
[  176.297636] sp : ffff800080003630
[  176.297743] x29: ffff800080003630 x28: 0000000000000008 x27:
ffff6828c49ad9f8
[  176.298093] x26: ffff6828c49ad000 x25: 0000000000000000 x24:
00000000000003e8
[  176.298430] x23: 0000000000000000 x22: ffff6828c4960b40 x21:
ffff6828c3b16d28
[  176.298652] x20: ffff6828c3167048 x19: ffff6828c3b16d00 x18:
0000000000000014
[  176.298926] x17: ffffb0476322f000 x16: ffffb7e164023730 x15:
0000000095744632
[  176.299296] x14: ffff6828c3f1c880 x13: 0000000000000002 x12:
ffffb7e137926a70
[  176.299574] x11: 0000000000000001 x10: ffff6828c3f1c898 x9 :
0000000000000000
[  176.300049] x8 : ffff6828c49bf070 x7 : 0008460f18d5f20e x6 :
f20e0100bebafeca
[  176.300302] x5 : ffff6828c7f918fe x4 : ffff6828c49bf070 x3 :
0000000000000000
[  176.300586] x2 : 0000000000000000 x1 : ffff6828c3c7ad00 x0 :
ffff6828c7f918f0
[  176.300889] Call trace:
[  176.301123]  br_nf_dev_queue_xmit+0x390/0x4ec [br_netfilter]
[  176.301411]  br_nf_post_routing+0x2a8/0x3e4 [br_netfilter]
[  176.301703]  nf_hook_slow+0x48/0x124
[  176.302060]  br_forward_finish+0xc8/0xe8 [bridge]
[  176.302371]  br_nf_hook_thresh+0x124/0x134 [br_netfilter]
[  176.302605]  br_nf_forward_finish+0x118/0x22c [br_netfilter]
[  176.302824]  br_nf_forward_ip.part.0+0x264/0x290 [br_netfilter]
[  176.303136]  br_nf_forward+0x2b8/0x4e0 [br_netfilter]
[  176.303359]  nf_hook_slow+0x48/0x124
[  176.303803]  __br_forward+0xc4/0x194 [bridge]
[  176.304013]  br_flood+0xd4/0x168 [bridge]
[  176.304300]  br_handle_frame_finish+0x1d4/0x5c4 [bridge]
[  176.304536]  br_nf_hook_thresh+0x124/0x134 [br_netfilter]
[  176.304978]  br_nf_pre_routing_finish+0x29c/0x494 [br_netfilter]
[  176.305188]  br_nf_pre_routing+0x250/0x524 [br_netfilter]
[  176.305428]  br_handle_frame+0x244/0x3cc [bridge]
[  176.305695]  __netif_receive_skb_core.constprop.0+0x33c/0xecc
[  176.306080]  __netif_receive_skb_one_core+0x40/0x8c
[  176.306197]  __netif_receive_skb+0x18/0x64
[  176.306369]  process_backlog+0x80/0x124
[  176.306540]  __napi_poll+0x38/0x17c
[  176.306636]  net_rx_action+0x124/0x26c
[  176.306758]  __do_softirq+0x100/0x26c
[  176.307051]  ____do_softirq+0x10/0x1c
[  176.307162]  call_on_irq_stack+0x24/0x4c
[  176.307289]  do_softirq_own_stack+0x1c/0x2c
[  176.307396]  do_softirq+0x54/0x6c
[  176.307485]  __local_bh_enable_ip+0x8c/0x98
[  176.307637]  __dev_queue_xmit+0x22c/0xd28
[  176.307775]  neigh_resolve_output+0xf4/0x1a0
[  176.308018]  ip_finish_output2+0x1c8/0x628
[  176.308137]  ip_do_fragment+0x5b4/0x658
[  176.308279]  ip_fragment.constprop.0+0x48/0xec
[  176.308420]  __ip_finish_output+0xa4/0x254
[  176.308593]  ip_finish_output+0x34/0x130
[  176.308814]  ip_output+0x6c/0x108
[  176.308929]  ip_send_skb+0x50/0xf0
[  176.309095]  ip_push_pending_frames+0x30/0x54
[  176.309254]  raw_sendmsg+0x758/0xaec
[  176.309568]  inet_sendmsg+0x44/0x70
[  176.309667]  __sys_sendto+0x110/0x178
[  176.309758]  __arm64_sys_sendto+0x28/0x38
[  176.309918]  invoke_syscall+0x48/0x110
[  176.310211]  el0_svc_common.constprop.0+0x40/0xe0
[  176.310353]  do_el0_svc+0x1c/0x28
[  176.310434]  el0_svc+0x34/0xb4
[  176.310551]  el0t_64_sync_handler+0x120/0x12c
[  176.310690]  el0t_64_sync+0x190/0x194
[  176.311066] Code: f9402e61 79402aa2 927ff821 f9400023 (f9408860)
[  176.315743] ---[ end trace 0000000000000000 ]---
[  176.316060] Kernel panic - not syncing: Oops: Fatal exception in
interrupt
[  176.316371] Kernel Offset: 0x37e0e3000000 from 0xffff800080000000
[  176.316564] PHYS_OFFSET: 0xffff97d780000000
[  176.316782] CPU features: 0x0,88000203,3c020000,0100421b
[  176.317210] Memory Limit: none
[  176.317527] ---[ end Kernel panic - not syncing: Oops: Fatal
Exception in interrupt ]---\

Fixes: 11538d039ac6 ("bridge: vlan dst_metadata hooks in ingress and egress paths")
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Signed-off-by: Andy Roulin &lt;aroulin@nvidia.com&gt;
Acked-by: Nikolay Aleksandrov &lt;razor@blackwall.org&gt;
Link: https://patch.msgid.link/20241001154400.22787-2-aroulin@nvidia.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
