linux/net/dsa
Vladimir Oltean 630fd4822a net: dsa: flush switchdev workqueue on bridge join error path
There is a race between switchdev_bridge_port_offload() and the
dsa_port_switchdev_sync_attrs() call right below it.

When switchdev_bridge_port_offload() finishes, FDB entries have been
replayed by the bridge, but are scheduled for deferred execution later.

However dsa_port_switchdev_sync_attrs -> dsa_port_can_apply_vlan_filtering()
may impose restrictions on the vlan_filtering attribute and refuse
offloading.

When this happens, the delayed FDB entries will dereference dp->bridge,
which is a NULL pointer because we have stopped the process of
offloading this bridge.

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
Workqueue: dsa_ordered dsa_slave_switchdev_event_work
pc : dsa_port_bridge_host_fdb_del+0x64/0x100
lr : dsa_slave_switchdev_event_work+0x130/0x1bc
Call trace:
 dsa_port_bridge_host_fdb_del+0x64/0x100
 dsa_slave_switchdev_event_work+0x130/0x1bc
 process_one_work+0x294/0x670
 worker_thread+0x80/0x460
---[ end trace 0000000000000000 ]---
Error: dsa_core: Must first remove VLAN uppers having VIDs also present in bridge.

Fix the bug by doing what we do on the normal bridge leave path as well,
which is to wait until the deferred FDB entries complete executing, then
exit.

The placement of dsa_flush_workqueue() after switchdev_bridge_port_unoffload()
guarantees that both the FDB additions and deletions on rollback are waited for.

Fixes: d7d0d423db ("net: dsa: flush switchdev workqueue when leaving the bridge")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20220507134550.1849834-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-05-09 18:08:04 -07:00
..
dsa2.c Revert "net: dsa: setup master before ports" 2022-04-13 12:38:06 +01:00
dsa_priv.h net: dsa: Handle MST state changes 2022-03-17 16:49:59 -07:00
dsa.c net: dsa: felix: avoid early deletion of host FDB entries 2022-03-09 11:12:10 +00:00
Kconfig net: dsa: tag_rtl8_4: add realtek 8 byte protocol 4 tag 2021-10-18 14:02:56 +01:00
Makefile net: dsa: tag_rtl8_4: add realtek 8 byte protocol 4 tag 2021-10-18 14:02:56 +01:00
master.c Revert "net: dsa: stop updating master MTU from master.c" 2022-04-01 11:59:01 +01:00
port.c net: dsa: flush switchdev workqueue on bridge join error path 2022-05-09 18:08:04 -07:00
slave.c net: dsa: flood multicast to CPU when slave has IFF_PROMISC 2022-04-25 11:46:24 +01:00
switch.c net: dsa: felix: avoid early deletion of host FDB entries 2022-03-09 11:12:10 +00:00
tag_8021q.c net: dsa: tag_8021q: rename dsa_8021q_bridge_tx_fwd_offload_vid 2022-02-27 11:06:14 +00:00
tag_ar9331.c net: dsa: remove the struct packet_type argument from dsa_device_ops::rcv() 2021-08-02 15:13:15 +01:00
tag_brcm.c net: dsa: create a helper for locating EtherType DSA headers on RX 2021-08-11 14:44:58 +01:00
tag_dsa.c net: dsa: tag_dsa: Fix tx from VLAN uppers on non-filtering bridges 2022-03-08 11:12:28 +01:00
tag_gswip.c net: dsa: remove the struct packet_type argument from dsa_device_ops::rcv() 2021-08-02 15:13:15 +01:00
tag_hellcreek.c net: dsa: hellcreek: Calculate checksums in tagger 2022-04-19 09:49:38 +02:00
tag_ksz.c net/dsa/tag_ksz.c: remove superfluous headers 2021-09-29 11:38:21 +01:00
tag_lan9303.c net: dsa: lan9303: handle hwaccel VLAN tags 2022-02-17 09:32:06 -08:00
tag_mtk.c net: dsa: create a helper for locating EtherType DSA headers on TX 2021-08-11 14:44:58 +01:00
tag_ocelot_8021q.c net: dsa: tag_8021q: merge RX and TX VLANs 2022-02-27 11:06:14 +00:00
tag_ocelot.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-12-23 16:09:58 -08:00
tag_qca.c net: dsa: tag_qca: add support for handling mgmt and MIB Ethernet packet 2022-02-02 14:43:59 +00:00
tag_rtl4_a.c net: dsa: tag_rtl4_a: Drop bit 9 from egress frames 2021-09-14 19:34:03 -07:00
tag_rtl8_4.c net: dsa: tag_rtl8_4: fix typo in modalias name 2022-03-09 20:36:24 -08:00
tag_sja1105.c net: dsa: tag_8021q: rename dsa_8021q_bridge_tx_fwd_offload_vid 2022-02-27 11:06:14 +00:00
tag_trailer.c net: dsa: remove the struct packet_type argument from dsa_device_ops::rcv() 2021-08-02 15:13:15 +01:00
tag_xrs700x.c net: dsa: remove the struct packet_type argument from dsa_device_ops::rcv() 2021-08-02 15:13:15 +01:00