Messages in this thread Patch in this message | | | From | Arnd Bergmann <> | Subject | [PATCH] netfilter: nf_flow_table: fix big-endian integer overflow | Date | Tue, 10 Dec 2019 21:24:28 +0100 |
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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(-)
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: -- 2.20.0
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