We need to explicitly check the length, else we may pass non-null terminated string to request_module(). Cc: stable@vger.kernel.org Fixes: bcf493428840 ("netfilter: ebtables: Fix extension lookup with identical name") Signed-off-by: Florian Westphal --- net/bridge/netfilter/ebtables.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c index 48187598cdd0..96c9a8f57c87 100644 --- a/net/bridge/netfilter/ebtables.c +++ b/net/bridge/netfilter/ebtables.c @@ -403,6 +403,9 @@ ebt_check_match(struct ebt_entry_match *m, struct xt_mtchk_param *par, left - sizeof(struct ebt_entry_match) < m->match_size) return -EINVAL; + if (strnlen(m->u.name, XT_EXTENSION_MAXNAMELEN) == XT_EXTENSION_MAXNAMELEN) + return -EINVAL; + match = xt_find_match(NFPROTO_BRIDGE, m->u.name, m->u.revision); if (IS_ERR(match) || match->family != NFPROTO_BRIDGE) { if (!IS_ERR(match)) -- 2.54.0