[PATCH 5.10 178/199] net: dsa: b53: fix an off by one in checking "vlan->vid"

Greg Kroah-Hartman
2021-01-26T10:05:52Z

From: Dan Carpenter <dan.carpenter@oracle.com>

commit 8e4052c32d6b4b39c1e13c652c7e33748d447409 upstream.

The > comparison should be >= to prevent accessing one element beyond
the end of the dev->vlans[] array in the caller function, b53_vlan_add().
The "dev->vlans" array is allocated in the b53_switch_init() function
and it has "dev->num_vlans" elements.

Fixes: a2482d2ce349 ("net: dsa: b53: Plug in VLAN support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/YAbxI97Dl/pmBy5V@mwanda
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/net/dsa/b53/b53_common.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/dsa/b53/b53_common.c
+++ b/drivers/net/dsa/b53/b53_common.c
@@ -1404,7 +1404,7 @@ int b53_vlan_prepare(struct dsa_switch *
!(vlan->flags & BRIDGE_VLAN_INFO_UNTAGGED))
return -EINVAL;

- if (vlan->vid_end > dev->num_vlans)
+ if (vlan->vid_end >= dev->num_vlans)
return -ERANGE;

b53_enable_vlan(dev, true, ds->vlan_filtering);