When we let the kernel pick up a rule location with RX_CLS_LOC_ANY, we would be able to overwrite the last rules because of a number of issues:
- the IPv4 code path would not be checking that rule_index is within bounds, the IPv6 code path would only be checking the second index and not the first one - find_first_zero_bit() needs to operate on the full bitmap size (priv->num_cfp_rules) otherwise it would be off by one in the results it returns and the checks against bcm_sf2_cfp_rule_size() would be non functioning Fixes: 3306145866b6 ("net: dsa: bcm_sf2: Move IPv4 CFP processing to specific functions") Fixes: ba0696c22e7c ("net: dsa: bcm_sf2: Add support for IPv6 CFP rules") Signed-off-by: Florian Fainelli <f.faine...@gmail.com> --- drivers/net/dsa/bcm_sf2_cfp.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/net/dsa/bcm_sf2_cfp.c b/drivers/net/dsa/bcm_sf2_cfp.c index 23b45da784cb..ade5fa3d747d 100644 --- a/drivers/net/dsa/bcm_sf2_cfp.c +++ b/drivers/net/dsa/bcm_sf2_cfp.c @@ -354,10 +354,13 @@ static int bcm_sf2_cfp_ipv4_rule_set(struct bcm_sf2_priv *priv, int port, /* Locate the first rule available */ if (fs->location == RX_CLS_LOC_ANY) rule_index = find_first_zero_bit(priv->cfp.used, - bcm_sf2_cfp_rule_size(priv)); + priv->num_cfp_rules); else rule_index = fs->location; + if (rule_index > bcm_sf2_cfp_rule_size(priv)) + return -ENOSPC; + layout = &udf_tcpip4_layout; /* We only use one UDF slice for now */ slice_num = bcm_sf2_get_slice_number(layout, 0); @@ -563,9 +566,11 @@ static int bcm_sf2_cfp_ipv6_rule_set(struct bcm_sf2_priv *priv, int port, */ if (fs->location == RX_CLS_LOC_ANY) rule_index[0] = find_first_zero_bit(priv->cfp.used, - bcm_sf2_cfp_rule_size(priv)); + priv->num_cfp_rules); else rule_index[0] = fs->location; + if (rule_index[0] > bcm_sf2_cfp_rule_size(priv)) + return -ENOSPC; /* Flag it as used (cleared on error path) such that we can immediately * obtain a second one to chain from. @@ -573,7 +578,7 @@ static int bcm_sf2_cfp_ipv6_rule_set(struct bcm_sf2_priv *priv, int port, set_bit(rule_index[0], priv->cfp.used); rule_index[1] = find_first_zero_bit(priv->cfp.used, - bcm_sf2_cfp_rule_size(priv)); + priv->num_cfp_rules); if (rule_index[1] > bcm_sf2_cfp_rule_size(priv)) { ret = -ENOSPC; goto out_err; -- 2.14.1