Users are able to cause program abort by passing a table name that doesn't exist: | # ebtables-nft -t dummy -P INPUT ACCEPT | ebtables: nft-cache.c:455: fetch_chain_cache: Assertion `t' failed. | Aborted Avoid this by checking table existence just like iptables-nft does upon parsing '-t' optarg. Since the list of tables is known and fixed, checking the given name's length is pointless. So just drop that check in return. With this patch in place, output looks much better: | # ebtables-nft -t dummy -P INPUT ACCEPT | ebtables v1.8.7 (nf_tables): table 'dummy' does not exist | Perhaps iptables or your kernel needs to be upgraded. Signed-off-by: Phil Sutter <phil@xxxxxx> --- iptables/xtables-eb.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/iptables/xtables-eb.c b/iptables/xtables-eb.c index cfa9317c78e94..5bb34d6d292a9 100644 --- a/iptables/xtables-eb.c +++ b/iptables/xtables-eb.c @@ -914,10 +914,10 @@ print_zero: xtables_error(PARAMETER_PROBLEM, "The -t option (seen in line %u) cannot be used in %s.\n", line, xt_params->program_name); - if (strlen(optarg) > EBT_TABLE_MAXNAMELEN - 1) - xtables_error(PARAMETER_PROBLEM, - "Table name length cannot exceed %d characters", - EBT_TABLE_MAXNAMELEN - 1); + if (!nft_table_builtin_find(h, optarg)) + xtables_error(VERSION_PROBLEM, + "table '%s' does not exist", + optarg); *table = optarg; table_set = true; break; -- 2.28.0
