kernel/linux.git/net/dsa, branch v5.15.209

net: dsa: free routing table on probe failure

2026-02-19T15:21:45+00:00

[ Upstream commit 8bf108d7161ffc6880ad13a0cc109de3cf631727 ] 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->ports, and maybe dst->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->ports. However, the dst->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->ops->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->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->rtable. Prior to that, each switch had its own ds->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 Link: https://patch.msgid.link/20250414213001.2957964-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski [ Backport the fix to net/dsa/dsa2.c in v5.15.y for dsa2.c was renamed back into dsa.c by commit 47d2ce03dcfb ("net: dsa: rename dsa2.c back into dsa.c and create its header") since v6.2. ] Signed-off-by: Bin Lan Signed-off-by: Greg Kroah-Hartman

net: dsa: tag_brcm: legacy: fix untagged rx on unbridged ports for bcm63xx

2025-12-06T21:09:25+00:00

[ Upstream commit 3d18a84eddde169d6dbf3c72cc5358b988c347d0 ] The internal switch on BCM63XX SoCs will unconditionally add 802.1Q VLAN tags on egress to CPU when 802.1Q mode is enabled. We do this unconditionally since commit ed409f3bbaa5 ("net: dsa: b53: Configure VLANs while not filtering"). This is fine for VLAN aware bridges, but for standalone ports and vlan unaware bridges this means all packets are tagged with the default VID, which is 0. While the kernel will treat that like untagged, this can break userspace applications processing raw packets, expecting untagged traffic, like STP daemons. This also breaks several bridge tests, where the tcpdump output then does not match the expected output anymore. Since 0 isn't a valid VID, just strip out the VLAN tag if we encounter it, unless the priority field is set, since that would be a valid tag again. Fixes: 964dbf186eaa ("net: dsa: tag_brcm: add support for legacy tags") Signed-off-by: Jonas Gorski Reviewed-by: Vladimir Oltean Link: https://patch.msgid.link/20251027194621.133301-1-jonas.gorski@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: dsa: microchip: linearize skb for tail-tagging switches

2025-09-09T16:50:23+00:00

[ Upstream commit ba54bce747fa9e07896c1abd9b48545f7b4b31d2 ] 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 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 Link: https://patch.msgid.link/20250515072920.2313014-1-jakob.unterwurzacher@cherry.de Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

net: dsa: microchip: update tag_ksz masks for KSZ9477 family

2025-09-09T16:50:23+00:00

[ Upstream commit 3f464b193d40e49299dcd087b10cc3b77cbbea68 ] Remove magic number 7 by introducing a GENMASK macro instead. Remove magic number 0x80 by using the BIT macro instead. Signed-off-by: Pieter Van Trappen Reviewed-by: Florian Fainelli Link: https://patch.msgid.link/20240909134301.75448-1-vtpieter@gmail.com Signed-off-by: Jakub Kicinski Stable-dep-of: ba54bce747fa ("net: dsa: microchip: linearize skb for tail-tagging switches") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

net: dsa: tag_brcm: legacy: fix pskb_may_pull length

2025-06-27T10:05:17+00:00

[ Upstream commit efdddc4484859082da6c7877ed144c8121c8ea55 ] 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 Reviewed-by: Florian Fainelli Link: https://patch.msgid.link/20250529124406.2513779-1-noltari@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: dsa: avoid refcount warnings when ds->ops->tag_8021q_vlan_del() fails

2025-05-02T05:44:11+00:00

[ Upstream commit 514eff7b0aa1c5eb645ddbb8676ef3e2d88a8b99 ] This is very similar to the problem and solution from commit 232deb3f9567 ("net: dsa: avoid refcount warnings when ->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 Link: https://patch.msgid.link/20250414213020.2959021-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: dsa: improve shutdown sequence

2025-01-09T12:28:42+00:00

commit 6c24a03a61a245fe34d47582898331fa034b6ccd upstream. Alexander Sverdlin presents 2 problems during shutdown with the lan9303 driver. One is specific to lan9303 and the other just happens to reproduce there. The first problem is that lan9303 is unique among DSA drivers in that it calls dev_get_drvdata() at "arbitrary runtime" (not probe, not shutdown, not remove): phy_state_machine() -> ... -> dsa_user_phy_read() -> ds->ops->phy_read() -> lan9303_phy_read() -> chip->ops->phy_read() -> lan9303_mdio_phy_read() -> dev_get_drvdata() But we never stop the phy_state_machine(), so it may continue to run after dsa_switch_shutdown(). Our common pattern in all DSA drivers is to set drvdata to NULL to suppress the remove() method that may come afterwards. But in this case it will result in an NPD. The second problem is that the way in which we set dp->conduit->dsa_ptr = NULL; is concurrent with receive packet processing. dsa_switch_rcv() checks once whether dev->dsa_ptr is NULL, but afterwards, rather than continuing to use that non-NULL value, dev->dsa_ptr is dereferenced again and again without NULL checks: dsa_conduit_find_user() and many other places. In between dereferences, there is no locking to ensure that what was valid once continues to be valid. Both problems have the common aspect that closing the conduit interface solves them. In the first case, dev_close(conduit) triggers the NETDEV_GOING_DOWN event in dsa_user_netdevice_event() which closes user ports as well. dsa_port_disable_rt() calls phylink_stop(), which synchronously stops the phylink state machine, and ds->ops->phy_read() will thus no longer call into the driver after this point. In the second case, dev_close(conduit) should do this, as per Documentation/networking/driver.rst: | Quiescence | ---------- | | After the ndo_stop routine has been called, the hardware must | not receive or transmit any data. All in flight packets must | be aborted. If necessary, poll or wait for completion of | any reset commands. So it should be sufficient to ensure that later, when we zeroize conduit->dsa_ptr, there will be no concurrent dsa_switch_rcv() call on this conduit. The addition of the netif_device_detach() function is to ensure that ioctls, rtnetlinks and ethtool requests on the user ports no longer propagate down to the driver - we're no longer prepared to handle them. The race condition actually did not exist when commit 0650bf52b31f ("net: dsa: be compatible with masters which unregister on shutdown") first introduced dsa_switch_shutdown(). It was created later, when we stopped unregistering the user interfaces from a bad spot, and we just replaced that sequence with a racy zeroization of conduit->dsa_ptr (one which doesn't ensure that the interfaces aren't up). Reported-by: Alexander Sverdlin Closes: https://lore.kernel.org/netdev/2d2e3bba17203c14a5ffdabc174e3b6bbb9ad438.camel@siemens.com/ Closes: https://lore.kernel.org/netdev/c1bf4de54e829111e0e4a70e7bd1cf523c9550ff.camel@siemens.com/ Fixes: ee534378f005 ("net: dsa: fix panic when DSA master device unbinds on shutdown") Reviewed-by: Alexander Sverdlin Tested-by: Alexander Sverdlin Signed-off-by: Vladimir Oltean Link: https://patch.msgid.link/20240913203549.3081071-1-vladimir.oltean@nxp.com Signed-off-by: Paolo Abeni Suggested-by: Vladimir Oltean Signed-off-by: Peilin He Reviewed-by: xu xin Signed-off-by: Kun Jiang Cc: Fan Yu Cc: Yutan Qiu Cc: Yaxin Wang Cc: tuqiang Cc: Yang Yang Cc: ye xingchen Cc: Yunkai Zhang Signed-off-by: Greg Kroah-Hartman

net: dsa: tag_sja1105: always prefer source port information from INCL_SRCPT

2024-06-16T11:39:54+00:00

commit c1ae02d876898b1b8ca1e12c6f84d7b406263800 upstream. Currently the sja1105 tagging protocol prefers using the source port information from the VLAN header if that is available, falling back to the INCL_SRCPT option if it isn't. The VLAN header is available for all frames except for META frames initiated by the switch (containing RX timestamps), and thus, the "if (is_link_local)" branch is practically dead. The tag_8021q source port identification has become more loose ("imprecise") and will report a plausible rather than exact bridge port, when under a bridge (be it VLAN-aware or VLAN-unaware). But link-local traffic always needs to know the precise source port. With incorrect source port reporting, for example PTP traffic over 2 bridged ports will all be seen on sockets opened on the first such port, which is incorrect. Now that the tagging protocol has been changed to make link-local frames always contain source port information, we can reverse the order of the checks so that we always give precedence to that information (which is always precise) in lieu of the tag_8021q VID which is only precise for a standalone port. Fixes: d7f9787a763f ("net: dsa: tag_8021q: add support for imprecise RX based on the VBID") Fixes: 91495f21fcec ("net: dsa: tag_8021q: replace the SVL bridging with VLAN-unaware IVL bridging") Signed-off-by: Vladimir Oltean Reviewed-by: Simon Horman Signed-off-by: Paolo Abeni [ Replaced the 2 original Fixes: tags with the correct one. Respun the change around the lack of a "vbid", corresponding to DSA FDB isolation, which appeared only in v5.18. ] Signed-off-by: Vladimir Oltean Signed-off-by: Greg Kroah-Hartman

net: dsa: introduce preferred_default_local_cpu_port and use on MT7530

2024-04-27T15:05:29+00:00

commit b79d7c14f48083abb3fb061370c0c64a569edf4c upstream. Since the introduction of the OF bindings, DSA has always had a policy that in case multiple CPU ports are present in the device tree, the numerically smallest one is always chosen. The MT7530 switch family, except the switch on the MT7988 SoC, has 2 CPU ports, 5 and 6, where port 6 is preferable on the MT7531BE switch because it has higher bandwidth. The MT7530 driver developers had 3 options: - to modify DSA when the MT7531 switch support was introduced, such as to prefer the better port - to declare both CPU ports in device trees as CPU ports, and live with the sub-optimal performance resulting from not preferring the better port - to declare just port 6 in the device tree as a CPU port Of course they chose the path of least resistance (3rd option), kicking the can down the road. The hardware description in the device tree is supposed to be stable - developers are not supposed to adopt the strategy of piecemeal hardware description, where the device tree is updated in lockstep with the features that the kernel currently supports. Now, as a result of the fact that they did that, any attempts to modify the device tree and describe both CPU ports as CPU ports would make DSA change its default selection from port 6 to 5, effectively resulting in a performance degradation visible to users with the MT7531BE switch as can be seen below. Without preferring port 6: [ ID][Role] Interval Transfer Bitrate Retr [ 5][TX-C] 0.00-20.00 sec 374 MBytes 157 Mbits/sec 734 sender [ 5][TX-C] 0.00-20.00 sec 373 MBytes 156 Mbits/sec receiver [ 7][RX-C] 0.00-20.00 sec 1.81 GBytes 778 Mbits/sec 0 sender [ 7][RX-C] 0.00-20.00 sec 1.81 GBytes 777 Mbits/sec receiver With preferring port 6: [ ID][Role] Interval Transfer Bitrate Retr [ 5][TX-C] 0.00-20.00 sec 1.99 GBytes 856 Mbits/sec 273 sender [ 5][TX-C] 0.00-20.00 sec 1.99 GBytes 855 Mbits/sec receiver [ 7][RX-C] 0.00-20.00 sec 1.72 GBytes 737 Mbits/sec 15 sender [ 7][RX-C] 0.00-20.00 sec 1.71 GBytes 736 Mbits/sec receiver Using one port for WAN and the other ports for LAN is a very popular use case which is what this test emulates. As such, this change proposes that we retroactively modify stable kernels (which don't support the modification of the CPU port assignments, so as to let user space fix the problem and restore the throughput) to keep the mt7530 driver preferring port 6 even with device trees where the hardware is more fully described. Fixes: c288575f7810 ("net: dsa: mt7530: Add the support of MT7531 switch") Signed-off-by: Vladimir Oltean Signed-off-by: Arınç ÜNAL Reviewed-by: Russell King (Oracle) Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller Signed-off-by: Arınç ÜNAL Signed-off-by: Greg Kroah-Hartman

net: dsa: fix panic when DSA master device unbinds on shutdown

2024-04-13T11:01:42+00:00

commit ee534378f00561207656663d93907583958339ae upstream. Rafael reports that on a system with LX2160A and Marvell DSA switches, if a reboot occurs while the DSA master (dpaa2-eth) is up, the following panic can be seen: systemd-shutdown[1]: Rebooting. Unable to handle kernel paging request at virtual address 00a0000800000041 [00a0000800000041] address between user and kernel address ranges Internal error: Oops: 96000004 [#1] PREEMPT SMP CPU: 6 PID: 1 Comm: systemd-shutdow Not tainted 5.16.5-00042-g8f5585009b24 #32 pc : dsa_slave_netdevice_event+0x130/0x3e4 lr : raw_notifier_call_chain+0x50/0x6c Call trace: dsa_slave_netdevice_event+0x130/0x3e4 raw_notifier_call_chain+0x50/0x6c call_netdevice_notifiers_info+0x54/0xa0 __dev_close_many+0x50/0x130 dev_close_many+0x84/0x120 unregister_netdevice_many+0x130/0x710 unregister_netdevice_queue+0x8c/0xd0 unregister_netdev+0x20/0x30 dpaa2_eth_remove+0x68/0x190 fsl_mc_driver_remove+0x20/0x5c __device_release_driver+0x21c/0x220 device_release_driver_internal+0xac/0xb0 device_links_unbind_consumers+0xd4/0x100 __device_release_driver+0x94/0x220 device_release_driver+0x28/0x40 bus_remove_device+0x118/0x124 device_del+0x174/0x420 fsl_mc_device_remove+0x24/0x40 __fsl_mc_device_remove+0xc/0x20 device_for_each_child+0x58/0xa0 dprc_remove+0x90/0xb0 fsl_mc_driver_remove+0x20/0x5c __device_release_driver+0x21c/0x220 device_release_driver+0x28/0x40 bus_remove_device+0x118/0x124 device_del+0x174/0x420 fsl_mc_bus_remove+0x80/0x100 fsl_mc_bus_shutdown+0xc/0x1c platform_shutdown+0x20/0x30 device_shutdown+0x154/0x330 __do_sys_reboot+0x1cc/0x250 __arm64_sys_reboot+0x20/0x30 invoke_syscall.constprop.0+0x4c/0xe0 do_el0_svc+0x4c/0x150 el0_svc+0x24/0xb0 el0t_64_sync_handler+0xa8/0xb0 el0t_64_sync+0x178/0x17c It can be seen from the stack trace that the problem is that the deregistration of the master causes a dev_close(), which gets notified as NETDEV_GOING_DOWN to dsa_slave_netdevice_event(). But dsa_switch_shutdown() has already run, and this has unregistered the DSA slave interfaces, and yet, the NETDEV_GOING_DOWN handler attempts to call dev_close_many() on those slave interfaces, leading to the problem. The previous attempt to avoid the NETDEV_GOING_DOWN on the master after dsa_switch_shutdown() was called seems improper. Unregistering the slave interfaces is unnecessary and unhelpful. Instead, after the slaves have stopped being uppers of the DSA master, we can now reset to NULL the master->dsa_ptr pointer, which will make DSA start ignoring all future notifier events on the master. Fixes: 0650bf52b31f ("net: dsa: be compatible with masters which unregister on shutdown") Reported-by: Rafael Richter Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller Cc: xu.xin16@zte.com.cn Cc: Vladimir Oltean Cc: Paolo Abeni Signed-off-by: Greg Kroah-Hartman