From c9b3b8207bc487de02cbca968927ba2c2cb46aaf Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 10 Dec 2019 21:24:28 +0100 Subject: netfilter: nf_flow_table: fix big-endian integer overflow 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 Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_flow_table_offload.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/netfilter/nf_flow_table_offload.c') diff --git a/net/netfilter/nf_flow_table_offload.c b/net/netfilter/nf_flow_table_offload.c index de7a0d1e15c8..0d72e5ccb47b 100644 --- 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_flow_match *match, 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: -- cgit v1.2.3