| Message ID | 20191210202443.2226043-1-arnd@arndb.de |
|---|---|
| State | Accepted |
| Commit | c9b3b8207bc487de02cbca968927ba2c2cb46aaf |
| Headers | show |
| Series | netfilter: nf_flow_table: fix big-endian integer overflow | expand |
On Tue, Dec 10, 2019 at 09:24:28PM +0100, Arnd Bergmann wrote: > 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> Applied, thanks.
diff --git a/net/netfilter/nf_flow_table_offload.c b/net/netfilter/nf_flow_table_offload.c index c54c9a6cc981..24543c45d501 100644 --- a/net/netfilter/nf_flow_table_offload.c +++ b/net/netfilter/nf_flow_table_offload.c @@ -77,7 +77,7 @@ 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:
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> --- I'm not sure if this is the correct fix, please check carefully --- net/netfilter/nf_flow_table_offload.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 2.20.0