[PATCH net 2/2] selftests: forwarding: bridge: add a state bypass with disabled VLAN filtering test
From: Nikolay Aleksandrov <razor@blackwall.org>
Date: 2025-11-04 12:03:23
Also in:
bridge
Subsystem:
kernel selftest framework, networking [general], networking [ipv4/ipv6], the rest · Maintainers:
Shuah Khan, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
Add a test which checks that port state bypass cannot happen if we have VLAN filtering disabled and MST enabled. Such bypass could lead to race condition when deleting a port because learning may happen after its state has been toggled to disabled while it's being deleted, leading to a use after free. Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org> --- .../net/forwarding/bridge_vlan_unaware.sh | 35 ++++++++++++++++++- 1 file changed, 34 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/net/forwarding/bridge_vlan_unaware.sh b/tools/testing/selftests/net/forwarding/bridge_vlan_unaware.sh
index 2b5700b61ffa..20769793310e 100755
--- a/tools/testing/selftests/net/forwarding/bridge_vlan_unaware.sh
+++ b/tools/testing/selftests/net/forwarding/bridge_vlan_unaware.sh@@ -1,7 +1,7 @@ #!/bin/bash # SPDX-License-Identifier: GPL-2.0 -ALL_TESTS="ping_ipv4 ping_ipv6 learning flooding pvid_change" +ALL_TESTS="ping_ipv4 ping_ipv6 learning flooding pvid_change mst_state_no_bypass" NUM_NETIFS=4 source lib.sh
@@ -114,6 +114,39 @@ pvid_change() ping_ipv6 " with bridge port $swp1 PVID deleted" } +mst_state_no_bypass() +{ + local mac=de:ad:be:ef:13:37 + + # Test that port state isn't bypassed when MST is enabled and VLAN + # filtering is disabled + RET=0 + + # MST can be enabled only when there are no VLANs + bridge vlan del vid 1 dev $swp1 + bridge vlan del vid 1 dev $swp2 + bridge vlan del vid 1 dev br0 self + + ip link set br0 type bridge mst_enabled 1 + check_err $? "Could not enable MST" + + bridge link set dev $swp1 state disabled + check_err $? "Could not set port state" + + $MZ $h1 -c 1 -p 64 -a $mac -t ip -q + + bridge fdb show brport $swp1 | grep -q de:ad:be:ef:13:37 + check_fail $? "FDB entry found when it shouldn't be" + + log_test "VLAN filtering disabled and MST enabled port state no bypass" + + ip link set br0 type bridge mst_enabled 0 + bridge link set dev $swp1 state forwarding + bridge vlan add vid 1 dev $swp1 pvid untagged + bridge vlan add vid 1 dev $swp2 pvid untagged + bridge vlan add vid 1 dev br0 self +} + trap cleanup EXIT setup_prepare
--
2.51.0