From cf2d347fe9cc384d4453a2a379e0dde8b97d081f Mon Sep 17 00:00:00 2001 From: Phil Sutter Date: Thu, 28 Jan 2021 01:09:56 +0100 Subject: [PATCH] ebtables: Exit gracefully on invalid table names 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 (cherry picked from commit 30c1d443896311e69762d6b51b63908ec602574f) --- 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; -- 2.31.1