From 1f327272e968a72de2d2a56da69124b40aa38744 Mon Sep 17 00:00:00 2001 From: Liping Zhang Date: Sun, 29 May 2016 19:25:37 +0800 Subject: parser: fix crash if we add a chain with an error chain type If we add a chain and specify the nonexistent chain type, chain_type_name_lookup will return a NULL pointer, and meet the assert condition in xstrdup. Fix crash like this: # nft add chain filter input {type none hook input priority 0\;} nft: utils.c:63: xstrdup: Assertion `s != ((void *)0)' failed. Aborted (core dumped) Signed-off-by: Liping Zhang Signed-off-by: Pablo Neira Ayuso --- src/parser_bison.y | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/src/parser_bison.y b/src/parser_bison.y index 0452b8f4..ef10dee2 100644 --- a/src/parser_bison.y +++ b/src/parser_bison.y @@ -1124,12 +1124,14 @@ type_identifier : STRING { $$ = $1; } hook_spec : TYPE STRING HOOK STRING dev_spec PRIORITY prio_spec { - $0->type = xstrdup(chain_type_name_lookup($2)); - if ($0->type == NULL) { + const char *chain_type = chain_type_name_lookup($2); + + if (chain_type == NULL) { erec_queue(error(&@2, "unknown chain type %s", $2), state->msgs); YYERROR; } + $0->type = xstrdup(chain_type); xfree($2); $0->hookstr = chain_hookname_lookup($4); -- cgit v1.2.3