[PATCH net v2 07/10] net: systemport: Fix out-of-bounds array accesses in DSA queue mapping
From: Florian Fainelli <florian.fainelli@broadcom.com>
Date: 2026-09-22 23:24:54
Also in:
lkml
Subsystem:
broadcom systemport ethernet driver, networking drivers, the rest · Maintainers:
Florian Fainelli, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
The priv->ring_map array has a fixed size of (DSA_MAX_PORTS * 8). In
bcm_sysport_select_queue(), bcm_sysport_map_queues(), and
bcm_sysport_unmap_queues(), indices calculated as
(qp + port * num_tx_queues) were accessed without checking against
ARRAY_SIZE(priv->ring_map). If unusual port or queue configurations are
encountered, this could lead to out-of-bounds array accesses.
Additionally, on SYSTEMPORT Lite, netif_set_real_num_tx_queues() was
called with slave_dev->num_tx_queues / 2, which could evaluate to 0 if
slave_dev->num_tx_queues is 1, causing netif_set_real_num_tx_queues() to
fail with -EINVAL.
Fix these by clamping the real number of queues to at least 1 and adding
bounds checks on priv->ring_map.
Fixes: d156576362c0 ("net: systemport: Establish lower/upper queue mapping")
Assisted-by: LLM
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
---
drivers/net/ethernet/broadcom/bcmsysport.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c
index ed4337af58da..4efcefd33b78 100644
--- a/drivers/net/ethernet/broadcom/bcmsysport.c
+++ b/drivers/net/ethernet/broadcom/bcmsysport.c@@ -2273,7 +2273,7 @@ static u16 bcm_sysport_select_queue(struct net_device *dev, struct sk_buff *skb, struct bcm_sysport_priv *priv = netdev_priv(dev); u16 queue = skb_get_queue_mapping(skb); struct bcm_sysport_tx_ring *tx_ring; - unsigned int q, port; + unsigned int q, port, index; if (!netdev_uses_dsa(dev)) return netdev_pick_tx(dev, skb, NULL);
@@ -2281,8 +2281,11 @@ static u16 bcm_sysport_select_queue(struct net_device *dev, struct sk_buff *skb, /* DSA tagging layer will have configured the correct queue */ q = BRCM_TAG_GET_QUEUE(queue); port = BRCM_TAG_GET_PORT(queue); - tx_ring = priv->ring_map[q + port * priv->per_port_num_tx_queues]; + index = q + port * priv->per_port_num_tx_queues; + if (unlikely(index >= ARRAY_SIZE(priv->ring_map))) + return netdev_pick_tx(dev, skb, NULL); + tx_ring = priv->ring_map[index]; if (unlikely(!tx_ring)) return netdev_pick_tx(dev, skb, NULL);
@@ -2329,7 +2332,8 @@ static int bcm_sysport_map_queues(struct net_device *dev, */ if (priv->is_lite) netif_set_real_num_tx_queues(slave_dev, - slave_dev->num_tx_queues / 2); + max_t(unsigned int, 1, + slave_dev->num_tx_queues / 2)); num_tx_queues = slave_dev->real_num_tx_queues;
@@ -2352,7 +2356,8 @@ static int bcm_sysport_map_queues(struct net_device *dev, ring->switch_queue = qp; ring->switch_port = port; ring->inspect = true; - priv->ring_map[qp + port * num_tx_queues] = ring; + if (qp + port * num_tx_queues < ARRAY_SIZE(priv->ring_map)) + priv->ring_map[qp + port * num_tx_queues] = ring; qp++; }
@@ -2383,7 +2388,8 @@ static int bcm_sysport_unmap_queues(struct net_device *dev, ring->inspect = false; qp = ring->switch_queue; - priv->ring_map[qp + port * num_tx_queues] = NULL; + if (qp + port * num_tx_queues < ARRAY_SIZE(priv->ring_map)) + priv->ring_map[qp + port * num_tx_queues] = NULL; } return 0;
--
2.34.1