This Linux kernel change "net: dsa: bcm_sf2: fix buffer overflow doing set_rxnfc" is included in the Linux 5.1 release. This change is authored by Dan Carpenter <dan.carpenter [at] oracle.com> on Tue Apr 30 13:44:19 2019 +0300. The commit for this change in Linux stable tree is f949a12 (patch).
net: dsa: bcm_sf2: fix buffer overflow doing set_rxnfc 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 <[email protected]> Signed-off-by: David S. Miller <[email protected]>
There are 6 lines of Linux source code added/deleted in this change. Code changes to Linux kernel are as follows.
drivers/net/dsa/bcm_sf2_cfp.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/net/dsa/bcm_sf2_cfp.c b/drivers/net/dsa/bcm_sf2_cfp.c index e6234d2..4212bc4 100644 --- a/drivers/net/dsa/bcm_sf2_cfp.c +++ b/drivers/net/dsa/bcm_sf2_cfp.c @@ -886,6 +886,9 @@ static int bcm_sf2_cfp_rule_set(struct dsa_switch *ds, int port, fs->m_ext.data)) 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; @@ -974,6 +977,9 @@ static int bcm_sf2_cfp_rule_del(struct bcm_sf2_priv *priv, int port, u32 loc) 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.