From: Pablo Neira Ayuso <pablo@netfilter.org>
To: netfilter-devel@vger.kernel.org
Cc: davem@davemloft.net, netdev@vger.kernel.org
Subject: [PATCH 1/9] netfilter: xt_hashlimit: reduce hashlimit_mutex scope for htable_put()
Date: Tue, 18 Feb 2020 23:20:53 +0100 [thread overview]
Message-ID: <20200218222101.635808-2-pablo@netfilter.org> (raw)
In-Reply-To: <20200218222101.635808-1-pablo@netfilter.org>
From: Cong Wang <xiyou.wangcong@gmail.com>
It is unnecessary to hold hashlimit_mutex for htable_destroy()
as it is already removed from the global hashtable and its
refcount is already zero.
Also, switch hinfo->use to refcount_t so that we don't have
to hold the mutex until it reaches zero in htable_put().
Reported-and-tested-by: syzbot+adf6c6c2be1c3a718121@syzkaller.appspotmail.com
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
net/netfilter/xt_hashlimit.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c
index bccd47cd7190..cc475a608f81 100644
--- a/net/netfilter/xt_hashlimit.c
+++ b/net/netfilter/xt_hashlimit.c
@@ -36,6 +36,7 @@
#include <linux/netfilter_ipv6/ip6_tables.h>
#include <linux/mutex.h>
#include <linux/kernel.h>
+#include <linux/refcount.h>
#include <uapi/linux/netfilter/xt_hashlimit.h>
#define XT_HASHLIMIT_ALL (XT_HASHLIMIT_HASH_DIP | XT_HASHLIMIT_HASH_DPT | \
@@ -114,7 +115,7 @@ struct dsthash_ent {
struct xt_hashlimit_htable {
struct hlist_node node; /* global list of all htables */
- int use;
+ refcount_t use;
u_int8_t family;
bool rnd_initialized;
@@ -315,7 +316,7 @@ static int htable_create(struct net *net, struct hashlimit_cfg3 *cfg,
for (i = 0; i < hinfo->cfg.size; i++)
INIT_HLIST_HEAD(&hinfo->hash[i]);
- hinfo->use = 1;
+ refcount_set(&hinfo->use, 1);
hinfo->count = 0;
hinfo->family = family;
hinfo->rnd_initialized = false;
@@ -420,7 +421,7 @@ static struct xt_hashlimit_htable *htable_find_get(struct net *net,
hlist_for_each_entry(hinfo, &hashlimit_net->htables, node) {
if (!strcmp(name, hinfo->name) &&
hinfo->family == family) {
- hinfo->use++;
+ refcount_inc(&hinfo->use);
return hinfo;
}
}
@@ -429,12 +430,11 @@ static struct xt_hashlimit_htable *htable_find_get(struct net *net,
static void htable_put(struct xt_hashlimit_htable *hinfo)
{
- mutex_lock(&hashlimit_mutex);
- if (--hinfo->use == 0) {
+ if (refcount_dec_and_mutex_lock(&hinfo->use, &hashlimit_mutex)) {
hlist_del(&hinfo->node);
+ mutex_unlock(&hashlimit_mutex);
htable_destroy(hinfo);
}
- mutex_unlock(&hashlimit_mutex);
}
/* The algorithm used is the Simple Token Bucket Filter (TBF)
--
2.11.0
next prev parent reply other threads:[~2020-02-18 22:21 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-18 22:20 [PATCH 0/9] Netfilter fixes for net Pablo Neira Ayuso
2020-02-18 22:20 ` Pablo Neira Ayuso [this message]
2020-02-18 22:20 ` [PATCH 2/9] netfilter: xt_hashlimit: limit the max size of hashtable Pablo Neira Ayuso
2020-02-18 22:20 ` [PATCH 3/9] netfilter: flowtable: skip offload setup if disabled Pablo Neira Ayuso
2020-02-18 22:20 ` [PATCH 4/9] netfilter: conntrack: remove two args from resolve_clash Pablo Neira Ayuso
2020-02-18 22:20 ` [PATCH 5/9] netfilter: conntrack: place confirm-bit setting in a helper Pablo Neira Ayuso
2020-02-18 22:20 ` [PATCH 6/9] netfilter: conntrack: split resolve_clash function Pablo Neira Ayuso
2020-02-18 22:20 ` [PATCH 7/9] netfilter: conntrack: allow insertion of clashing entries Pablo Neira Ayuso
2020-02-18 22:21 ` [PATCH 8/9] netfilter: nft_set_pipapo: Fix mapping table example in comments Pablo Neira Ayuso
2020-02-18 22:21 ` [PATCH 9/9] netfilter: nft_set_pipapo: Don't abuse unlikely() in pipapo_refill() Pablo Neira Ayuso
2020-02-18 23:45 ` [PATCH 0/9] Netfilter fixes for net David Miller
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200218222101.635808-2-pablo@netfilter.org \
--to=pablo@netfilter.org \
--cc=davem@davemloft.net \
--cc=netdev@vger.kernel.org \
--cc=netfilter-devel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).