From 2964e5fe855b060dcc153a50605f79b5d424f934 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Fri, 6 Sep 2019 17:12:30 +0200
Git-commit: b44492afd2b123f605c3aa2cbeee3398d9ebbcc5
Patch-mainline: v5.4-rc1
References: git-fixes
Subject: [PATCH] netfilter: nf_tables_offload: avoid excessive stack usage
The nft_offload_ctx structure is much too large to put on the
stack:
net/netfilter/nf_tables_offload.c:31:23: error: stack frame size of 1200 bytes in function 'nft_flow_rule_create' [-Werror,-Wframe-larger-than=]
Use dynamic allocation here, as we do elsewhere in the same
function.
Fixes: c9626a2cbdb2 ("netfilter: nf_tables: add hardware offload support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Denis Kirjanov <denis.kirjanov@suse.com>
---
net/netfilter/nf_tables_offload.c | 20 +++++++++++++-------
1 file changed, 13 insertions(+), 7 deletions(-)
diff --git a/net/netfilter/nf_tables_offload.c b/net/netfilter/nf_tables_offload.c
index 04fbab60e808..006cdb0f5900 100644
--- a/net/netfilter/nf_tables_offload.c
+++ b/net/netfilter/nf_tables_offload.c
@@ -30,11 +30,7 @@ static struct nft_flow_rule *nft_flow_rule_alloc(int num_actions)
struct nft_flow_rule *nft_flow_rule_create(const struct nft_rule *rule)
{
- struct nft_offload_ctx ctx = {
- .dep = {
- .type = NFT_OFFLOAD_DEP_UNSPEC,
- },
- };
+ struct nft_offload_ctx *ctx;
struct nft_flow_rule *flow;
int num_actions = 0, err;
struct nft_expr *expr;
@@ -52,21 +48,31 @@ struct nft_flow_rule *nft_flow_rule_create(const struct nft_rule *rule)
return ERR_PTR(-ENOMEM);
expr = nft_expr_first(rule);
+
+ ctx = kzalloc(sizeof(struct nft_offload_ctx), GFP_KERNEL);
+ if (!ctx) {
+ err = -ENOMEM;
+ goto err_out;
+ }
+ ctx->dep.type = NFT_OFFLOAD_DEP_UNSPEC;
+
while (expr->ops && expr != nft_expr_last(rule)) {
if (!expr->ops->offload) {
err = -EOPNOTSUPP;
goto err_out;
}
- err = expr->ops->offload(&ctx, flow, expr);
+ err = expr->ops->offload(ctx, flow, expr);
if (err < 0)
goto err_out;
expr = nft_expr_next(expr);
}
- flow->proto = ctx.dep.l3num;
+ flow->proto = ctx->dep.l3num;
+ kfree(ctx);
return flow;
err_out:
+ kfree(ctx);
nft_flow_rule_destroy(flow);
return ERR_PTR(err);
--
2.16.4