5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Hangyu Hua <hbh25y@xxxxxxxxx> [ Upstream commit 51fe0a470543f345e3c62b6798929de3ddcedc1d ] rules is allocated in ethtool_get_rxnfc and the size is determined by rule_cnt from user space. So rule_cnt needs to be check before using rules to avoid OOB writing or NULL pointer dereference. Fixes: 90b509b39ac9 ("net: mvpp2: cls: Add Classification offload support") Signed-off-by: Hangyu Hua <hbh25y@xxxxxxxxx> Reviewed-by: Marcin Wojtas <mw@xxxxxxxxxxxx> Reviewed-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c index 31dde6fbdbdca..7a2293a5bcc9f 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c @@ -4233,6 +4233,11 @@ static int mvpp2_ethtool_get_rxnfc(struct net_device *dev, break; case ETHTOOL_GRXCLSRLALL: for (i = 0; i < MVPP2_N_RFS_ENTRIES_PER_FLOW; i++) { + if (loc == info->rule_cnt) { + ret = -EMSGSIZE; + break; + } + if (port->rfs_rules[i]) rules[loc++] = i; } -- 2.40.1