[PATCH 5.0 08/32] net: dsa: bcm_sf2: fix buffer overflow doing set_rxnfc

Greg Kroah-Hartman
2019-05-04T10:26:58Z

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

[ Upstream commit f949a12fd697479f68d99dc65e9bbab68ee49043 ]

The "fs->location" is a u32 that comes from the user in ethtool_set_rxnfc().
We can't pass unclamped values to test_bit() or it results in an out of
bounds access beyond the end of the bitmap.

Fixes: 7318166cacad ("net: dsa: bcm_sf2: Add support for ethtool::rxnfc")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/dsa/bcm_sf2_cfp.c | 6 ++++++
1 file changed, 6 insertions(+)

--- a/drivers/net/dsa/bcm_sf2_cfp.c
+++ b/drivers/net/dsa/bcm_sf2_cfp.c
@@ -854,6 +854,9 @@ static int bcm_sf2_cfp_rule_set(struct d
fs->m_ext.data[1]))
return -EINVAL;

+ if (fs->location != RX_CLS_LOC_ANY && fs->location >= CFP_NUM_RULES)
+ return -EINVAL;
+
if (fs->location != RX_CLS_LOC_ANY &&
test_bit(fs->location, priv->cfp.used))
return -EBUSY;
@@ -942,6 +945,9 @@ static int bcm_sf2_cfp_rule_del(struct b
struct cfp_rule *rule;
int ret;

+ if (loc >= CFP_NUM_RULES)
+ return -EINVAL;
+
/* Refuse deleting unused rules, and those that are not unique since
* that could leave IPv6 rules with one of the chained rule in the
* table.