From 378bbd58311f38d926c8bad7deff288b41f4ac20 Mon Sep 17 00:00:00 2001 From: Andrea Claudi Date: Fri, 10 Sep 2021 18:08:39 +0200 Subject: [PATCH] ipvs: check that ip_vs_conn_tab_bits is between 8 and 20 ip_vs_conn_tab_bits may be provided by the user through the conn_tab_bits module parameter. If this value is greater than 31, or less than 0, the shift operator used to derive tab_size causes undefined behaviour. Fix this checking ip_vs_conn_tab_bits value to be in the range specified in ipvs Kconfig. If not, simply use default value. Fixes: 471a7f10380a ("IPVS: Allow boot time change of hash size") Reported-by: Yi Chen Signed-off-by: Andrea Claudi Acked-by: Julian Anastasov Acked-by: Simon Horman Signed-off-by: Pablo Neira Ayuso --- net/netfilter/ipvs/ip_vs_conn.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/netfilter/ipvs/ip_vs_conn.c b/net/netfilter/ipvs/ip_vs_conn.c index c100c6b112c81..2c467c422dc63 100644 --- a/net/netfilter/ipvs/ip_vs_conn.c +++ b/net/netfilter/ipvs/ip_vs_conn.c @@ -1468,6 +1468,10 @@ int __init ip_vs_conn_init(void) int idx; /* Compute size and mask */ + if (ip_vs_conn_tab_bits < 8 || ip_vs_conn_tab_bits > 20) { + pr_info("conn_tab_bits not in [8, 20]. Using default value\n"); + ip_vs_conn_tab_bits = CONFIG_IP_VS_TAB_BITS; + } ip_vs_conn_tab_size = 1 << ip_vs_conn_tab_bits; ip_vs_conn_tab_mask = ip_vs_conn_tab_size - 1; -- 2.39.5