TCP_FLAG_* are 32-bit big endian constants, not 16-bit. So on big endian machines, you need to shift them down to fit the 16-bit tcp.mask here. This surfaced through ARM allmodconfig, which is big endian: net/netfilter/nf_flow_table_offload.c: In function 'nf_flow_rule_match': net/netfilter/nf_flow_table_offload.c:91:21: warning: unsigned conversion from 'int' to '__be16' {aka 'short unsigned int'} changes value from '327680' to '0' [-Woverflow] Need to convert to/from host word order to keep LE/BE behaving the same. Fixes: c29f74e0df7a ("netfilter: nf_flow_table: hardware offload support") Signed-off-by: Olof Johansson <olof@xxxxxxxxx> --- net/netfilter/nf_flow_table_offload.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/netfilter/nf_flow_table_offload.c b/net/netfilter/nf_flow_table_offload.c index de7a0d1e15c88..e32ff796378c6 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 = htons(ntohl(TCP_FLAG_RST | TCP_FLAG_FIN) >> 16); match->dissector.used_keys |= BIT(FLOW_DISSECTOR_KEY_TCP); break; case IPPROTO_UDP: -- 2.11.0