path: root/iptables
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authorJan Engelhardt <>2011-08-27 17:59:52 +0200
committerJan Engelhardt <>2011-08-27 18:36:12 +0200
commitfdb2a27825e558393fb715374c07873830d4d149 (patch)
tree8c5cceb56cb199013147609e818f132539100ccf /iptables
parentdebcf48f6a72914a9c06e99b175ad64ef1f6f1cb (diff)
xtoptions: fill in fallback value for nvals
Parsing for libxt_conntrack rev 2 is done by using rev 2's option structure, which specifies XTTYPE_PORT, and using rev 3's parser skeleton, which uses cb->nvals. Reading cb->nvals when not using XTTYPE_PORTRC (or any other multi-value type) is undefined behavior. Make it defined. Since XTTYPE_NONE is the only type that can take void, nvals logically ought to be 1. References: Signed-off-by: Jan Engelhardt <>
Diffstat (limited to 'iptables')
1 files changed, 6 insertions, 0 deletions
diff --git a/iptables/xtoptions.c b/iptables/xtoptions.c
index 04344af4..5f617a42 100644
--- a/iptables/xtoptions.c
+++ b/iptables/xtoptions.c
@@ -826,6 +826,12 @@ void xtables_option_parse(struct xt_option_call *cb)
"%s: option \"--%s\" requires an argument.\n",
cb->ext_name, entry->name);
+ /*
+ * Fill in fallback value for "nvals", in case an extension (as it
+ * happened with libxt_conntrack.2) tries to read it, despite not using
+ * a *RC option type.
+ */
+ cb->nvals = 1;
if (entry->type <= ARRAY_SIZE(xtopt_subparse) &&
xtopt_subparse[entry->type] != NULL)