<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/net/dsa, branch v6.17</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>net: s/dev_close_many/netif_close_many/</title>
<updated>2025-07-19T00:27:47+00:00</updated>
<author>
<name>Stanislav Fomichev</name>
<email>sdf@fomichev.me</email>
</author>
<published>2025-07-17T17:23:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=88d3cec28274f9c15355835466c0c694e313680e'/>
<id>88d3cec28274f9c15355835466c0c694e313680e</id>
<content type='text'>
Commit cc34acd577f1 ("docs: net: document new locking reality")
introduced netif_ vs dev_ function semantics: the former expects locked
netdev, the latter takes care of the locking. We don't strictly
follow this semantics on either side, but there are more dev_xxx handlers
now that don't fit. Rename them to netif_xxx where appropriate.

netif_close_many is used only by vlan/dsa and one mtk driver, so move it into
NETDEV_INTERNAL namespace.

Signed-off-by: Stanislav Fomichev &lt;sdf@fomichev.me&gt;
Link: https://patch.msgid.link/20250717172333.1288349-8-sdf@fomichev.me
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit cc34acd577f1 ("docs: net: document new locking reality")
introduced netif_ vs dev_ function semantics: the former expects locked
netdev, the latter takes care of the locking. We don't strictly
follow this semantics on either side, but there are more dev_xxx handlers
now that don't fit. Rename them to netif_xxx where appropriate.

netif_close_many is used only by vlan/dsa and one mtk driver, so move it into
NETDEV_INTERNAL namespace.

Signed-off-by: Stanislav Fomichev &lt;sdf@fomichev.me&gt;
Link: https://patch.msgid.link/20250717172333.1288349-8-sdf@fomichev.me
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: dsa: tag_brcm: add support for legacy FCS tags</title>
<updated>2025-06-18T00:52:01+00:00</updated>
<author>
<name>Álvaro Fernández Rojas</name>
<email>noltari@gmail.com</email>
</author>
<published>2025-06-14T07:59:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ef07df397a621707903ef0d294a7df11f80cf206'/>
<id>ef07df397a621707903ef0d294a7df11f80cf206</id>
<content type='text'>
Add support for legacy Broadcom FCS tags, which are similar to
DSA_TAG_PROTO_BRCM_LEGACY.
BCM5325 and BCM5365 switches require including the original FCS value and
length, as opposed to BCM63xx switches.
Adding the original FCS value and length to DSA_TAG_PROTO_BRCM_LEGACY would
impact performance of BCM63xx switches, so it's better to create a new tag.

Signed-off-by: Álvaro Fernández Rojas &lt;noltari@gmail.com&gt;
Reviewed-by: Florian Fainelli &lt;florian.fainelli@broadcom.com&gt;
Link: https://patch.msgid.link/20250614080000.1884236-3-noltari@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>
Add support for legacy Broadcom FCS tags, which are similar to
DSA_TAG_PROTO_BRCM_LEGACY.
BCM5325 and BCM5365 switches require including the original FCS value and
length, as opposed to BCM63xx switches.
Adding the original FCS value and length to DSA_TAG_PROTO_BRCM_LEGACY would
impact performance of BCM63xx switches, so it's better to create a new tag.

Signed-off-by: Álvaro Fernández Rojas &lt;noltari@gmail.com&gt;
Reviewed-by: Florian Fainelli &lt;florian.fainelli@broadcom.com&gt;
Link: https://patch.msgid.link/20250614080000.1884236-3-noltari@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: dsa: tag_brcm: legacy: reorganize functions</title>
<updated>2025-06-18T00:51:59+00:00</updated>
<author>
<name>Álvaro Fernández Rojas</name>
<email>noltari@gmail.com</email>
</author>
<published>2025-06-14T07:59:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a4daaf063f8269a5881154c5b77c5ef6639d65d3'/>
<id>a4daaf063f8269a5881154c5b77c5ef6639d65d3</id>
<content type='text'>
Move brcm_leg_tag_rcv() definition to top.
This function is going to be shared between two different tags.

Reviewed-by: Florian Fainelli &lt;florian.fainelli@broadcom.com&gt;
Signed-off-by: Álvaro Fernández Rojas &lt;noltari@gmail.com&gt;
Link: https://patch.msgid.link/20250614080000.1884236-2-noltari@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>
Move brcm_leg_tag_rcv() definition to top.
This function is going to be shared between two different tags.

Reviewed-by: Florian Fainelli &lt;florian.fainelli@broadcom.com&gt;
Signed-off-by: Álvaro Fernández Rojas &lt;noltari@gmail.com&gt;
Link: https://patch.msgid.link/20250614080000.1884236-2-noltari@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: dsa: tag_brcm: legacy: fix pskb_may_pull length</title>
<updated>2025-05-31T02:20:18+00:00</updated>
<author>
<name>Álvaro Fernández Rojas</name>
<email>noltari@gmail.com</email>
</author>
<published>2025-05-29T12:44:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=efdddc4484859082da6c7877ed144c8121c8ea55'/>
<id>efdddc4484859082da6c7877ed144c8121c8ea55</id>
<content type='text'>
BRCM_LEG_PORT_ID was incorrectly used for pskb_may_pull length.
The correct check is BRCM_LEG_TAG_LEN + VLAN_HLEN, or 10 bytes.

Fixes: 964dbf186eaa ("net: dsa: tag_brcm: add support for legacy tags")
Signed-off-by: Álvaro Fernández Rojas &lt;noltari@gmail.com&gt;
Reviewed-by: Florian Fainelli &lt;florian.fainelli@broadcom.com&gt;
Link: https://patch.msgid.link/20250529124406.2513779-1-noltari@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>
BRCM_LEG_PORT_ID was incorrectly used for pskb_may_pull length.
The correct check is BRCM_LEG_TAG_LEN + VLAN_HLEN, or 10 bytes.

Fixes: 964dbf186eaa ("net: dsa: tag_brcm: add support for legacy tags")
Signed-off-by: Álvaro Fernández Rojas &lt;noltari@gmail.com&gt;
Reviewed-by: Florian Fainelli &lt;florian.fainelli@broadcom.com&gt;
Link: https://patch.msgid.link/20250529124406.2513779-1-noltari@gmail.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/netdev/net</title>
<updated>2025-05-22T16:42:41+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2025-05-22T16:42:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=33e1b1b3991ba8c0d02b2324a582e084272205d6'/>
<id>33e1b1b3991ba8c0d02b2324a582e084272205d6</id>
<content type='text'>
Cross-merge networking fixes after downstream PR (net-6.15-rc8).

Conflicts:
  80f2ab46c2ee ("irdma: free iwdev-&gt;rf after removing MSI-X")
  4bcc063939a5 ("ice, irdma: fix an off by one in error handling code")
  c24a65b6a27c ("iidc/ice/irdma: Update IDC to support multiple consumers")
https://lore.kernel.org/20250513130630.280ee6c5@canb.auug.org.au

No extra adjacent changes.

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Cross-merge networking fixes after downstream PR (net-6.15-rc8).

Conflicts:
  80f2ab46c2ee ("irdma: free iwdev-&gt;rf after removing MSI-X")
  4bcc063939a5 ("ice, irdma: fix an off by one in error handling code")
  c24a65b6a27c ("iidc/ice/irdma: Update IDC to support multiple consumers")
https://lore.kernel.org/20250513130630.280ee6c5@canb.auug.org.au

No extra adjacent changes.

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: dsa: microchip: linearize skb for tail-tagging switches</title>
<updated>2025-05-16T23:00:17+00:00</updated>
<author>
<name>Jakob Unterwurzacher</name>
<email>jakobunt@gmail.com</email>
</author>
<published>2025-05-15T07:29:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ba54bce747fa9e07896c1abd9b48545f7b4b31d2'/>
<id>ba54bce747fa9e07896c1abd9b48545f7b4b31d2</id>
<content type='text'>
The pointer arithmentic for accessing the tail tag only works
for linear skbs.

For nonlinear skbs, it reads uninitialized memory inside the
skb headroom, essentially randomizing the tag. I have observed
it gets set to 6 most of the time.

Example where ksz9477_rcv thinks that the packet from port 1 comes from port 6
(which does not exist for the ksz9896 that's in use), dropping the packet.
Debug prints added by me (not included in this patch):

	[  256.645337] ksz9477_rcv:323 tag0=6
	[  256.645349] skb len=47 headroom=78 headlen=0 tailroom=0
	               mac=(64,14) mac_len=14 net=(78,0) trans=78
	               shinfo(txflags=0 nr_frags=1 gso(size=0 type=0 segs=0))
	               csum(0x0 start=0 offset=0 ip_summed=0 complete_sw=0 valid=0 level=0)
	               hash(0x0 sw=0 l4=0) proto=0x00f8 pkttype=1 iif=3
	               priority=0x0 mark=0x0 alloc_cpu=0 vlan_all=0x0
	               encapsulation=0 inner(proto=0x0000, mac=0, net=0, trans=0)
	[  256.645377] dev name=end1 feat=0x0002e10200114bb3
	[  256.645386] skb headroom: 00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	[  256.645395] skb headroom: 00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	[  256.645403] skb headroom: 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	[  256.645411] skb headroom: 00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	[  256.645420] skb headroom: 00000040: ff ff ff ff ff ff 00 1c 19 f2 e2 db 08 06
	[  256.645428] skb frag:     00000000: 00 01 08 00 06 04 00 01 00 1c 19 f2 e2 db 0a 02
	[  256.645436] skb frag:     00000010: 00 83 00 00 00 00 00 00 0a 02 a0 2f 00 00 00 00
	[  256.645444] skb frag:     00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01
	[  256.645452] ksz_common_rcv:92 dsa_conduit_find_user returned NULL

Call skb_linearize before trying to access the tag.

This patch fixes ksz9477_rcv which is used by the ksz9896 I have at
hand, and also applies the same fix to ksz8795_rcv which seems to have
the same problem.

Signed-off-by: Jakob Unterwurzacher &lt;jakob.unterwurzacher@cherry.de&gt;
CC: stable@vger.kernel.org
Fixes: 016e43a26bab ("net: dsa: ksz: Add KSZ8795 tag code")
Fixes: 8b8010fb7876 ("dsa: add support for Microchip KSZ tail tagging")
Reviewed-by: Vladimir Oltean &lt;olteanv@gmail.com&gt;
Link: https://patch.msgid.link/20250515072920.2313014-1-jakob.unterwurzacher@cherry.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 pointer arithmentic for accessing the tail tag only works
for linear skbs.

For nonlinear skbs, it reads uninitialized memory inside the
skb headroom, essentially randomizing the tag. I have observed
it gets set to 6 most of the time.

Example where ksz9477_rcv thinks that the packet from port 1 comes from port 6
(which does not exist for the ksz9896 that's in use), dropping the packet.
Debug prints added by me (not included in this patch):

	[  256.645337] ksz9477_rcv:323 tag0=6
	[  256.645349] skb len=47 headroom=78 headlen=0 tailroom=0
	               mac=(64,14) mac_len=14 net=(78,0) trans=78
	               shinfo(txflags=0 nr_frags=1 gso(size=0 type=0 segs=0))
	               csum(0x0 start=0 offset=0 ip_summed=0 complete_sw=0 valid=0 level=0)
	               hash(0x0 sw=0 l4=0) proto=0x00f8 pkttype=1 iif=3
	               priority=0x0 mark=0x0 alloc_cpu=0 vlan_all=0x0
	               encapsulation=0 inner(proto=0x0000, mac=0, net=0, trans=0)
	[  256.645377] dev name=end1 feat=0x0002e10200114bb3
	[  256.645386] skb headroom: 00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	[  256.645395] skb headroom: 00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	[  256.645403] skb headroom: 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	[  256.645411] skb headroom: 00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
	[  256.645420] skb headroom: 00000040: ff ff ff ff ff ff 00 1c 19 f2 e2 db 08 06
	[  256.645428] skb frag:     00000000: 00 01 08 00 06 04 00 01 00 1c 19 f2 e2 db 0a 02
	[  256.645436] skb frag:     00000010: 00 83 00 00 00 00 00 00 0a 02 a0 2f 00 00 00 00
	[  256.645444] skb frag:     00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01
	[  256.645452] ksz_common_rcv:92 dsa_conduit_find_user returned NULL

Call skb_linearize before trying to access the tag.

This patch fixes ksz9477_rcv which is used by the ksz9896 I have at
hand, and also applies the same fix to ksz8795_rcv which seems to have
the same problem.

Signed-off-by: Jakob Unterwurzacher &lt;jakob.unterwurzacher@cherry.de&gt;
CC: stable@vger.kernel.org
Fixes: 016e43a26bab ("net: dsa: ksz: Add KSZ8795 tag code")
Fixes: 8b8010fb7876 ("dsa: add support for Microchip KSZ tail tagging")
Reviewed-by: Vladimir Oltean &lt;olteanv@gmail.com&gt;
Link: https://patch.msgid.link/20250515072920.2313014-1-jakob.unterwurzacher@cherry.de
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: dsa: convert to ndo_hwtstamp_get() and ndo_hwtstamp_set()</title>
<updated>2025-05-09T23:34:09+00:00</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2025-05-08T09:52:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6c14058edfd01cdc0d3018b9069643b0da7c3e80'/>
<id>6c14058edfd01cdc0d3018b9069643b0da7c3e80</id>
<content type='text'>
New timestamping API was introduced in commit 66f7223039c0 ("net: add
NDOs for configuring hardware timestamping") from kernel v6.6. It is
time to convert DSA to the new API, so that the ndo_eth_ioctl() path can
be removed completely.

Move the ds-&gt;ops-&gt;port_hwtstamp_get() and ds-&gt;ops-&gt;port_hwtstamp_set()
calls from dsa_user_ioctl() to dsa_user_hwtstamp_get() and
dsa_user_hwtstamp_set().

Due to the fact that the underlying ifreq type changes to
kernel_hwtstamp_config, the drivers and the Ocelot switchdev front-end,
all hooked up directly or indirectly, must also be converted all at once.

The conversion also updates the comment from dsa_port_supports_hwtstamp(),
which is no longer true because kernel_hwtstamp_config is kernel memory
and does not need copy_to_user(). I've deliberated whether it is
necessary to also update "err != -EOPNOTSUPP" to a more general "!err",
but all drivers now either return 0 or -EOPNOTSUPP.

The existing logic from the ocelot_ioctl() function, to avoid
configuring timestamping if the PHY supports the operation, is obsoleted
by more advanced core logic in dev_set_hwtstamp_phylib().

This is only a partial preparation for proper PHY timestamping support.
None of these switch driver currently sets up PTP traps for PHY
timestamping, so setting dev-&gt;see_all_hwtstamp_requests is not yet
necessary and the conversion is relatively trivial.

Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Tested-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt; # felix, sja1105, mv88e6xxx
Reviewed-by: Vadim Fedorenko &lt;vadim.fedorenko@linux.dev&gt;
Link: https://patch.msgid.link/20250508095236.887789-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
New timestamping API was introduced in commit 66f7223039c0 ("net: add
NDOs for configuring hardware timestamping") from kernel v6.6. It is
time to convert DSA to the new API, so that the ndo_eth_ioctl() path can
be removed completely.

Move the ds-&gt;ops-&gt;port_hwtstamp_get() and ds-&gt;ops-&gt;port_hwtstamp_set()
calls from dsa_user_ioctl() to dsa_user_hwtstamp_get() and
dsa_user_hwtstamp_set().

Due to the fact that the underlying ifreq type changes to
kernel_hwtstamp_config, the drivers and the Ocelot switchdev front-end,
all hooked up directly or indirectly, must also be converted all at once.

The conversion also updates the comment from dsa_port_supports_hwtstamp(),
which is no longer true because kernel_hwtstamp_config is kernel memory
and does not need copy_to_user(). I've deliberated whether it is
necessary to also update "err != -EOPNOTSUPP" to a more general "!err",
but all drivers now either return 0 or -EOPNOTSUPP.

The existing logic from the ocelot_ioctl() function, to avoid
configuring timestamping if the PHY supports the operation, is obsoleted
by more advanced core logic in dev_set_hwtstamp_phylib().

This is only a partial preparation for proper PHY timestamping support.
None of these switch driver currently sets up PTP traps for PHY
timestamping, so setting dev-&gt;see_all_hwtstamp_requests is not yet
necessary and the conversion is relatively trivial.

Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Tested-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt; # felix, sja1105, mv88e6xxx
Reviewed-by: Vadim Fedorenko &lt;vadim.fedorenko@linux.dev&gt;
Link: https://patch.msgid.link/20250508095236.887789-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: dsa: avoid refcount warnings when ds-&gt;ops-&gt;tag_8021q_vlan_del() fails</title>
<updated>2025-04-17T01:14:44+00:00</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2025-04-14T21:30:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=514eff7b0aa1c5eb645ddbb8676ef3e2d88a8b99'/>
<id>514eff7b0aa1c5eb645ddbb8676ef3e2d88a8b99</id>
<content type='text'>
This is very similar to the problem and solution from commit
232deb3f9567 ("net: dsa: avoid refcount warnings when
-&gt;port_{fdb,mdb}_del returns error"), except for the
dsa_port_do_tag_8021q_vlan_del() operation.

Fixes: c64b9c05045a ("net: dsa: tag_8021q: add proper cross-chip notifier support")
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Link: https://patch.msgid.link/20250414213020.2959021-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This is very similar to the problem and solution from commit
232deb3f9567 ("net: dsa: avoid refcount warnings when
-&gt;port_{fdb,mdb}_del returns error"), except for the
dsa_port_do_tag_8021q_vlan_del() operation.

Fixes: c64b9c05045a ("net: dsa: tag_8021q: add proper cross-chip notifier support")
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Link: https://patch.msgid.link/20250414213020.2959021-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: dsa: free routing table on probe failure</title>
<updated>2025-04-17T01:14:44+00:00</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2025-04-14T21:30:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8bf108d7161ffc6880ad13a0cc109de3cf631727'/>
<id>8bf108d7161ffc6880ad13a0cc109de3cf631727</id>
<content type='text'>
If complete = true in dsa_tree_setup(), it means that we are the last
switch of the tree which is successfully probing, and we should be
setting up all switches from our probe path.

After "complete" becomes true, dsa_tree_setup_cpu_ports() or any
subsequent function may fail. If that happens, the entire tree setup is
in limbo: the first N-1 switches have successfully finished probing
(doing nothing but having allocated persistent memory in the tree's
dst-&gt;ports, and maybe dst-&gt;rtable), and switch N failed to probe, ending
the tree setup process before anything is tangible from the user's PoV.

If switch N fails to probe, its memory (ports) will be freed and removed
from dst-&gt;ports. However, the dst-&gt;rtable elements pointing to its ports,
as created by dsa_link_touch(), will remain there, and will lead to
use-after-free if dereferenced.

If dsa_tree_setup_switches() returns -EPROBE_DEFER, which is entirely
possible because that is where ds-&gt;ops-&gt;setup() is, we get a kasan
report like this:

==================================================================
BUG: KASAN: slab-use-after-free in mv88e6xxx_setup_upstream_port+0x240/0x568
Read of size 8 at addr ffff000004f56020 by task kworker/u8:3/42

Call trace:
 __asan_report_load8_noabort+0x20/0x30
 mv88e6xxx_setup_upstream_port+0x240/0x568
 mv88e6xxx_setup+0xebc/0x1eb0
 dsa_register_switch+0x1af4/0x2ae0
 mv88e6xxx_register_switch+0x1b8/0x2a8
 mv88e6xxx_probe+0xc4c/0xf60
 mdio_probe+0x78/0xb8
 really_probe+0x2b8/0x5a8
 __driver_probe_device+0x164/0x298
 driver_probe_device+0x78/0x258
 __device_attach_driver+0x274/0x350

Allocated by task 42:
 __kasan_kmalloc+0x84/0xa0
 __kmalloc_cache_noprof+0x298/0x490
 dsa_switch_touch_ports+0x174/0x3d8
 dsa_register_switch+0x800/0x2ae0
 mv88e6xxx_register_switch+0x1b8/0x2a8
 mv88e6xxx_probe+0xc4c/0xf60
 mdio_probe+0x78/0xb8
 really_probe+0x2b8/0x5a8
 __driver_probe_device+0x164/0x298
 driver_probe_device+0x78/0x258
 __device_attach_driver+0x274/0x350

Freed by task 42:
 __kasan_slab_free+0x48/0x68
 kfree+0x138/0x418
 dsa_register_switch+0x2694/0x2ae0
 mv88e6xxx_register_switch+0x1b8/0x2a8
 mv88e6xxx_probe+0xc4c/0xf60
 mdio_probe+0x78/0xb8
 really_probe+0x2b8/0x5a8
 __driver_probe_device+0x164/0x298
 driver_probe_device+0x78/0x258
 __device_attach_driver+0x274/0x350

The simplest way to fix the bug is to delete the routing table in its
entirety. dsa_tree_setup_routing_table() has no problem in regenerating
it even if we deleted links between ports other than those of switch N,
because dsa_link_touch() first checks whether the port pair already
exists in dst-&gt;rtable, allocating if not.

The deletion of the routing table in its entirety already exists in
dsa_tree_teardown(), so refactor that into a function that can also be
called from the tree setup error path.

In my analysis of the commit to blame, it is the one which added
dsa_link elements to dst-&gt;rtable. Prior to that, each switch had its own
ds-&gt;rtable which is freed when the switch fails to probe. But the tree
is potentially persistent memory.

Fixes: c5f51765a1f6 ("net: dsa: list DSA links in the fabric")
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Link: https://patch.msgid.link/20250414213001.2957964-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If complete = true in dsa_tree_setup(), it means that we are the last
switch of the tree which is successfully probing, and we should be
setting up all switches from our probe path.

After "complete" becomes true, dsa_tree_setup_cpu_ports() or any
subsequent function may fail. If that happens, the entire tree setup is
in limbo: the first N-1 switches have successfully finished probing
(doing nothing but having allocated persistent memory in the tree's
dst-&gt;ports, and maybe dst-&gt;rtable), and switch N failed to probe, ending
the tree setup process before anything is tangible from the user's PoV.

If switch N fails to probe, its memory (ports) will be freed and removed
from dst-&gt;ports. However, the dst-&gt;rtable elements pointing to its ports,
as created by dsa_link_touch(), will remain there, and will lead to
use-after-free if dereferenced.

If dsa_tree_setup_switches() returns -EPROBE_DEFER, which is entirely
possible because that is where ds-&gt;ops-&gt;setup() is, we get a kasan
report like this:

==================================================================
BUG: KASAN: slab-use-after-free in mv88e6xxx_setup_upstream_port+0x240/0x568
Read of size 8 at addr ffff000004f56020 by task kworker/u8:3/42

Call trace:
 __asan_report_load8_noabort+0x20/0x30
 mv88e6xxx_setup_upstream_port+0x240/0x568
 mv88e6xxx_setup+0xebc/0x1eb0
 dsa_register_switch+0x1af4/0x2ae0
 mv88e6xxx_register_switch+0x1b8/0x2a8
 mv88e6xxx_probe+0xc4c/0xf60
 mdio_probe+0x78/0xb8
 really_probe+0x2b8/0x5a8
 __driver_probe_device+0x164/0x298
 driver_probe_device+0x78/0x258
 __device_attach_driver+0x274/0x350

Allocated by task 42:
 __kasan_kmalloc+0x84/0xa0
 __kmalloc_cache_noprof+0x298/0x490
 dsa_switch_touch_ports+0x174/0x3d8
 dsa_register_switch+0x800/0x2ae0
 mv88e6xxx_register_switch+0x1b8/0x2a8
 mv88e6xxx_probe+0xc4c/0xf60
 mdio_probe+0x78/0xb8
 really_probe+0x2b8/0x5a8
 __driver_probe_device+0x164/0x298
 driver_probe_device+0x78/0x258
 __device_attach_driver+0x274/0x350

Freed by task 42:
 __kasan_slab_free+0x48/0x68
 kfree+0x138/0x418
 dsa_register_switch+0x2694/0x2ae0
 mv88e6xxx_register_switch+0x1b8/0x2a8
 mv88e6xxx_probe+0xc4c/0xf60
 mdio_probe+0x78/0xb8
 really_probe+0x2b8/0x5a8
 __driver_probe_device+0x164/0x298
 driver_probe_device+0x78/0x258
 __device_attach_driver+0x274/0x350

The simplest way to fix the bug is to delete the routing table in its
entirety. dsa_tree_setup_routing_table() has no problem in regenerating
it even if we deleted links between ports other than those of switch N,
because dsa_link_touch() first checks whether the port pair already
exists in dst-&gt;rtable, allocating if not.

The deletion of the routing table in its entirety already exists in
dsa_tree_teardown(), so refactor that into a function that can also be
called from the tree setup error path.

In my analysis of the commit to blame, it is the one which added
dsa_link elements to dst-&gt;rtable. Prior to that, each switch had its own
ds-&gt;rtable which is freed when the switch fails to probe. But the tree
is potentially persistent memory.

Fixes: c5f51765a1f6 ("net: dsa: list DSA links in the fabric")
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Link: https://patch.msgid.link/20250414213001.2957964-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: dsa: clean up FDB, MDB, VLAN entries on unbind</title>
<updated>2025-04-17T01:14:43+00:00</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2025-04-14T21:29:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7afb5fb42d4950f33af2732b8147c552659f79b7'/>
<id>7afb5fb42d4950f33af2732b8147c552659f79b7</id>
<content type='text'>
As explained in many places such as commit b117e1e8a86d ("net: dsa:
delete dsa_legacy_fdb_add and dsa_legacy_fdb_del"), DSA is written given
the assumption that higher layers have balanced additions/deletions.
As such, it only makes sense to be extremely vocal when those
assumptions are violated and the driver unbinds with entries still
present.

But Ido Schimmel points out a very simple situation where that is wrong:
https://lore.kernel.org/netdev/ZDazSM5UsPPjQuKr@shredder/
(also briefly discussed by me in the aforementioned commit).

Basically, while the bridge bypass operations are not something that DSA
explicitly documents, and for the majority of DSA drivers this API
simply causes them to go to promiscuous mode, that isn't the case for
all drivers. Some have the necessary requirements for bridge bypass
operations to do something useful - see dsa_switch_supports_uc_filtering().

Although in tools/testing/selftests/net/forwarding/local_termination.sh,
we made an effort to popularize better mechanisms to manage address
filters on DSA interfaces from user space - namely macvlan for unicast,
and setsockopt(IP_ADD_MEMBERSHIP) - through mtools - for multicast, the
fact is that 'bridge fdb add ... self static local' also exists as
kernel UAPI, and might be useful to someone, even if only for a quick
hack.

It seems counter-productive to block that path by implementing shim
.ndo_fdb_add and .ndo_fdb_del operations which just return -EOPNOTSUPP
in order to prevent the ndo_dflt_fdb_add() and ndo_dflt_fdb_del() from
running, although we could do that.

Accepting that cleanup is necessary seems to be the only option.
Especially since we appear to be coming back at this from a different
angle as well. Russell King is noticing that the WARN_ON() triggers even
for VLANs:
https://lore.kernel.org/netdev/Z_li8Bj8bD4-BYKQ@shell.armlinux.org.uk/

What happens in the bug report above is that dsa_port_do_vlan_del() fails,
then the VLAN entry lingers on, and then we warn on unbind and leak it.

This is not a straight revert of the blamed commit, but we now add an
informational print to the kernel log (to still have a way to see
that bugs exist), and some extra comments gathered from past years'
experience, to justify the logic.

Fixes: 0832cd9f1f02 ("net: dsa: warn if port lists aren't empty in dsa_port_teardown")
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Link: https://patch.msgid.link/20250414212930.2956310-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
As explained in many places such as commit b117e1e8a86d ("net: dsa:
delete dsa_legacy_fdb_add and dsa_legacy_fdb_del"), DSA is written given
the assumption that higher layers have balanced additions/deletions.
As such, it only makes sense to be extremely vocal when those
assumptions are violated and the driver unbinds with entries still
present.

But Ido Schimmel points out a very simple situation where that is wrong:
https://lore.kernel.org/netdev/ZDazSM5UsPPjQuKr@shredder/
(also briefly discussed by me in the aforementioned commit).

Basically, while the bridge bypass operations are not something that DSA
explicitly documents, and for the majority of DSA drivers this API
simply causes them to go to promiscuous mode, that isn't the case for
all drivers. Some have the necessary requirements for bridge bypass
operations to do something useful - see dsa_switch_supports_uc_filtering().

Although in tools/testing/selftests/net/forwarding/local_termination.sh,
we made an effort to popularize better mechanisms to manage address
filters on DSA interfaces from user space - namely macvlan for unicast,
and setsockopt(IP_ADD_MEMBERSHIP) - through mtools - for multicast, the
fact is that 'bridge fdb add ... self static local' also exists as
kernel UAPI, and might be useful to someone, even if only for a quick
hack.

It seems counter-productive to block that path by implementing shim
.ndo_fdb_add and .ndo_fdb_del operations which just return -EOPNOTSUPP
in order to prevent the ndo_dflt_fdb_add() and ndo_dflt_fdb_del() from
running, although we could do that.

Accepting that cleanup is necessary seems to be the only option.
Especially since we appear to be coming back at this from a different
angle as well. Russell King is noticing that the WARN_ON() triggers even
for VLANs:
https://lore.kernel.org/netdev/Z_li8Bj8bD4-BYKQ@shell.armlinux.org.uk/

What happens in the bug report above is that dsa_port_do_vlan_del() fails,
then the VLAN entry lingers on, and then we warn on unbind and leak it.

This is not a straight revert of the blamed commit, but we now add an
informational print to the kernel log (to still have a way to see
that bugs exist), and some extra comments gathered from past years'
experience, to justify the logic.

Fixes: 0832cd9f1f02 ("net: dsa: warn if port lists aren't empty in dsa_port_teardown")
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Link: https://patch.msgid.link/20250414212930.2956310-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
