net: dsa: bcm_sf2: Fix overflow checks

commit d0802dc411f469569a537283b6f3833af47aece9 upstream.

Commit f949a12fd697 ("net: dsa: bcm_sf2: fix buffer overflow doing
set_rxnfc") tried to fix the some user controlled buffer overflows in
bcm_sf2_cfp_rule_set() and bcm_sf2_cfp_rule_del() but the fix was using
CFP_NUM_RULES, which while it is correct not to overflow the bitmaps, is
not representative of what the device actually supports. Correct that by
using bcm_sf2_cfp_rule_size() instead.

The latter subtracts the number of rules by 1, so change the checks from
greater than or equal to greater than accordingly.

Fixes: f949a12fd697 ("net: dsa: bcm_sf2: fix buffer overflow doing set_rxnfc")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Florian Fainelli
2020-03-30 14:38:46 -07:00
committed by Greg Kroah-Hartman
parent 3b098eb748
commit c6ca2a6911

View File

@@ -130,17 +130,14 @@ static int bcm_sf2_cfp_rule_set(struct dsa_switch *ds, int port,
(fs->m_ext.vlan_etype || fs->m_ext.data[1]))
return -EINVAL;
if (fs->location != RX_CLS_LOC_ANY && fs->location >= CFP_NUM_RULES)
if (fs->location != RX_CLS_LOC_ANY &&
fs->location > bcm_sf2_cfp_rule_size(priv))
return -EINVAL;
if (fs->location != RX_CLS_LOC_ANY &&
test_bit(fs->location, priv->cfp.used))
return -EBUSY;
if (fs->location != RX_CLS_LOC_ANY &&
fs->location > bcm_sf2_cfp_rule_size(priv))
return -EINVAL;
ip_frag = be32_to_cpu(fs->m_ext.data[0]);
/* We do not support discarding packets, check that the
@@ -333,7 +330,7 @@ static int bcm_sf2_cfp_rule_del(struct bcm_sf2_priv *priv, int port,
int ret;
u32 reg;
if (loc >= CFP_NUM_RULES)
if (loc > bcm_sf2_cfp_rule_size(priv))
return -EINVAL;
/* Refuse deletion of unused rules, and the default reserved rule */