[PATCH] netfiler: protect nft_ct_pcpu_template_refcnt with mutex

From: Pavel Skripkin
Date: Mon Aug 09 2021 - 17:13:38 EST


/* .... */

Signed-off-by: Pavel Skripkin <paskripkin@xxxxxxxxx>
---
net/netfilter/nft_ct.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nft_ct.c b/net/netfilter/nft_ct.c
index 337e22d8b40b..99b1de14ff7e 100644
--- a/net/netfilter/nft_ct.c
+++ b/net/netfilter/nft_ct.c
@@ -41,6 +41,7 @@ struct nft_ct_helper_obj {
#ifdef CONFIG_NF_CONNTRACK_ZONES
static DEFINE_PER_CPU(struct nf_conn *, nft_ct_pcpu_template);
static unsigned int nft_ct_pcpu_template_refcnt __read_mostly;
+static DEFINE_MUTEX(nft_ct_pcpu_mutex);
#endif

static u64 nft_ct_get_eval_counter(const struct nf_conn_counter *c,
@@ -525,8 +526,10 @@ static void __nft_ct_set_destroy(const struct nft_ctx *ctx, struct nft_ct *priv)
#endif
#ifdef CONFIG_NF_CONNTRACK_ZONES
case NFT_CT_ZONE:
+ mutex_lock(&nft_ct_pcpu_mutex);
if (--nft_ct_pcpu_template_refcnt == 0)
nft_ct_tmpl_put_pcpu();
+ mutex_unlock(&nft_ct_pcpu_mutex);
break;
#endif
default:
@@ -564,9 +567,13 @@ static int nft_ct_set_init(const struct nft_ctx *ctx,
#endif
#ifdef CONFIG_NF_CONNTRACK_ZONES
case NFT_CT_ZONE:
- if (!nft_ct_tmpl_alloc_pcpu())
+ mutex_lock(&nft_ct_pcpu_mutex);
+ if (!nft_ct_tmpl_alloc_pcpu()) {
+ mutex_unlock(&nft_ct_pcpu_mutex);
return -ENOMEM;
+ }
nft_ct_pcpu_template_refcnt++;
+ mutex_unlock(&nft_ct_pcpu_mutex);
len = sizeof(u16);
break;
#endif
--
2.32.0


--------------21B9763F459AE640797A1F93--