From: Arnd Bergmann <arnd@arndb.de>
Date: Tue, 10 Dec 2019 21:24:28 +0100
Subject: netfilter: nf_flow_table: fix big-endian integer overflow
Patch-mainline: v5.5-rc5
Git-commit: c9b3b8207bc487de02cbca968927ba2c2cb46aaf
References: bsc#1176447
In some configurations, gcc reports an integer overflow:
net/netfilter/nf_flow_table_offload.c: In function 'nf_flow_rule_match':
net/netfilter/nf_flow_table_offload.c:80:21: error: unsigned conversion from 'int' to '__be16' {aka 'short unsigned int'} changes value from '327680' to '0' [-Werror=overflow]
mask->tcp.flags = TCP_FLAG_RST | TCP_FLAG_FIN;
^~~~~~~~~~~~
From what I can tell, we want the upper 16 bits of these constants,
so they need to be shifted in cpu-endian mode.
Fixes: c29f74e0df7a ("netfilter: nf_flow_table: hardware offload support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
net/netfilter/nf_flow_table_offload.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/netfilter/nf_flow_table_offload.c
+++ b/net/netfilter/nf_flow_table_offload.c
@@ -88,7 +88,7 @@ static int nf_flow_rule_match(struct nf_
switch (tuple->l4proto) {
case IPPROTO_TCP:
key->tcp.flags = 0;
- mask->tcp.flags = TCP_FLAG_RST | TCP_FLAG_FIN;
+ mask->tcp.flags = cpu_to_be16(be32_to_cpu(TCP_FLAG_RST | TCP_FLAG_FIN) >> 16);
match->dissector.used_keys |= BIT(FLOW_DISSECTOR_KEY_TCP);
break;
case IPPROTO_UDP: