Re: [PATCH] net/mlx4: fix MAC table total count corruption in __mlx4_unregister_mac()
From: Tariq Toukan
Date: Tue Jan 27 2026 - 01:28:30 EST
On 22/01/2026 20:39, Kery Qi wrote:
In __mlx4_unregister_mac(), when operating in mf_bonded mode
(SR-IOV with bonding), it appears that the code might be incorrectly
decrementing table->total instead of dup_table->total when cleaning
up the duplicate table entry.
If this is the case, it would cause the primary table's total counter
to be decremented twice (once for itself and once when it should
decrement the duplicate table), leading to counter corruption.
Over time, table->total could become negative, which would
break the "table->total == table->max" fullness check in
__mlx4_register_mac().
The registration path correctly increments both counters:
++table->total;
if (dup) {
...
++dup_table->total;
}
However, the unregistration path seems to have a typo:
--table->total;
if (dup) {
...
--table->total; // Should this be --dup_table->total?
Fixes: 5f61385d2ebc2 ("net/mlx4_core: Keep VLAN/MAC tables mirrored in multifunc HA mode")
Signed-off-by: Kery Qi <qikeyu2017@xxxxxxxxx>
---
Hi Kery,
1. Commit message is phrased as an RFC, with questions and uncertainty.
Please re-phrase.
2. Do you hit an actual failure here? What are the steps? What error do you see?
Other than that, code LGTM.
drivers/net/ethernet/mellanox/mlx4/port.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/mellanox/mlx4/port.c b/drivers/net/ethernet/mellanox/mlx4/port.c
index e3d0b13c1610..6d0295c471da 100644
--- a/drivers/net/ethernet/mellanox/mlx4/port.c
+++ b/drivers/net/ethernet/mellanox/mlx4/port.c
@@ -410,7 +410,7 @@ void __mlx4_unregister_mac(struct mlx4_dev *dev, u8 port, u64 mac)
if (mlx4_set_port_mac_table(dev, dup_port, dup_table->entries))
mlx4_warn(dev, "Fail to set mac in duplicate port %d during unregister\n", dup_port);
- --table->total;
+ --dup_table->total;
}
out:
if (dup) {