diff mbox series

[iptables] ebtables: Exit gracefully on invalid table names

Message ID 20210128001705.13967-1-phil@nwl.cc
State Accepted
Delegated to: Pablo Neira
Headers show
Series [iptables] ebtables: Exit gracefully on invalid table names | expand

Commit Message

Phil Sutter Jan. 28, 2021, 12:17 a.m. UTC
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@nwl.cc>
---
 iptables/xtables-eb.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
diff mbox series

Patch

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;