From: Vladimir Oltean vladimir.oltean@nxp.com
[ Upstream commit a398b9ea0c3b791b7a0f4c6029a62cf628f97f22 ]
There was a regression introduced by the blamed commit, where pinging to a VLAN-unaware bridge would fail with the repeated message "Couldn't decode source port" coming from the tagging protocol driver.
When receiving packets with a bridge_vid as determined by dsa_tag_8021q_bridge_join(), dsa_8021q_rcv() will decode: - source_port = 0 (which isn't really valid, more like "don't know") - switch_id = 0 (which isn't really valid, more like "don't know") - vbid = value in range 1-7
Since the blamed patch has reversed the order of the checks, we are now going to believe that source_port != -1 and switch_id != -1, so they're valid, but they aren't.
The minimal solution to the problem is to only populate source_port and switch_id with what dsa_8021q_rcv() came up with, if the vbid is zero, i.e. the source port information is trustworthy.
Fixes: c1ae02d87689 ("net: dsa: tag_sja1105: always prefer source port information from INCL_SRCPT") Signed-off-by: Vladimir Oltean vladimir.oltean@nxp.com Reviewed-by: Simon Horman simon.horman@corigine.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/dsa/tag_sja1105.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/net/dsa/tag_sja1105.c b/net/dsa/tag_sja1105.c index 731dc3a111ef3..6e3699d859dbd 100644 --- a/net/dsa/tag_sja1105.c +++ b/net/dsa/tag_sja1105.c @@ -568,11 +568,14 @@ static struct sk_buff *sja1105_rcv(struct sk_buff *skb, * if available. This allows us to not overwrite a valid source * port and switch ID with zeroes when receiving link-local * frames from a VLAN-unaware bridged port (non-zero vbid) or a - * VLAN-aware bridged port (non-zero vid). + * VLAN-aware bridged port (non-zero vid). Furthermore, the + * tag_8021q source port information is only of trust when the + * vbid is 0 (precise port). Otherwise, tmp_source_port and + * tmp_switch_id will be zeroes. */ - if (source_port == -1) + if (vbid == 0 && source_port == -1) source_port = tmp_source_port; - if (switch_id == -1) + if (vbid == 0 && switch_id == -1) switch_id = tmp_switch_id; } else if (source_port == -1 && switch_id == -1) { /* Packets with no source information have no chance of