From: Florian Westphal fw@strlen.de
[ Upstream commit 9332d27d7918182add34e8043f6a754530fdd022 ]
This WARN can trigger because some of the names fed to the module autoload function can be of arbitrary length.
Remove the WARN and add limits for all NLA_STRING attributes.
Reported-by: syzbot+0e63ae76d117ae1c3a01@syzkaller.appspotmail.com Fixes: 452238e8d5ffd8 ("netfilter: nf_tables: add and use helper for module autoload") Signed-off-by: Florian Westphal fw@strlen.de Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/netfilter/nf_tables_api.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index b0cd1cee412b2..6fa315b73a66a 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -22,6 +22,8 @@ #include <net/net_namespace.h> #include <net/sock.h>
+#define NFT_MODULE_AUTOLOAD_LIMIT (MODULE_NAME_LEN - sizeof("nft-expr-255-")) + static LIST_HEAD(nf_tables_expressions); static LIST_HEAD(nf_tables_objects); static LIST_HEAD(nf_tables_flowtables); @@ -519,7 +521,7 @@ static void nft_request_module(struct net *net, const char *fmt, ...) va_start(args, fmt); ret = vsnprintf(module_name, MODULE_NAME_LEN, fmt, args); va_end(args); - if (WARN(ret >= MODULE_NAME_LEN, "truncated: '%s' (len %d)", module_name, ret)) + if (ret >= MODULE_NAME_LEN) return;
mutex_unlock(&net->nft.commit_mutex); @@ -1175,7 +1177,8 @@ static const struct nla_policy nft_chain_policy[NFTA_CHAIN_MAX + 1] = { .len = NFT_CHAIN_MAXNAMELEN - 1 }, [NFTA_CHAIN_HOOK] = { .type = NLA_NESTED }, [NFTA_CHAIN_POLICY] = { .type = NLA_U32 }, - [NFTA_CHAIN_TYPE] = { .type = NLA_STRING }, + [NFTA_CHAIN_TYPE] = { .type = NLA_STRING, + .len = NFT_MODULE_AUTOLOAD_LIMIT }, [NFTA_CHAIN_COUNTERS] = { .type = NLA_NESTED }, [NFTA_CHAIN_FLAGS] = { .type = NLA_U32 }, }; @@ -2089,7 +2092,8 @@ static const struct nft_expr_type *nft_expr_type_get(struct net *net, }
static const struct nla_policy nft_expr_policy[NFTA_EXPR_MAX + 1] = { - [NFTA_EXPR_NAME] = { .type = NLA_STRING }, + [NFTA_EXPR_NAME] = { .type = NLA_STRING, + .len = NFT_MODULE_AUTOLOAD_LIMIT }, [NFTA_EXPR_DATA] = { .type = NLA_NESTED }, };
@@ -3932,7 +3936,8 @@ static const struct nla_policy nft_set_elem_policy[NFTA_SET_ELEM_MAX + 1] = { [NFTA_SET_ELEM_USERDATA] = { .type = NLA_BINARY, .len = NFT_USERDATA_MAXLEN }, [NFTA_SET_ELEM_EXPR] = { .type = NLA_NESTED }, - [NFTA_SET_ELEM_OBJREF] = { .type = NLA_STRING }, + [NFTA_SET_ELEM_OBJREF] = { .type = NLA_STRING, + .len = NFT_OBJ_MAXNAMELEN - 1 }, };
static const struct nla_policy nft_set_elem_list_policy[NFTA_SET_ELEM_LIST_MAX + 1] = {