[PATCH 07/11] netfilter: xt_RATEEST: acquire xt_rateest_mutex for hash insert
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: 2018-02-07 17:42:43
Also in:
netfilter-devel
Subsystem:
netfilter, networking [general], the rest · Maintainers:
Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Cong Wang <redacted>
rateest_hash is supposed to be protected by xt_rateest_mutex,
and, as suggested by Eric, lookup and insert should be atomic,
so we should acquire the xt_rateest_mutex once for both.
So introduce a non-locking helper for internal use and keep the
locking one for external.
Reported-by: <redacted>
Fixes: 5859034d7eb8 ("[NETFILTER]: x_tables: add RATEEST target")
Signed-off-by: Cong Wang <redacted>
Reviewed-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
net/netfilter/xt_RATEEST.c | 22 +++++++++++++++++-----
1 file changed, 17 insertions(+), 5 deletions(-)
diff --git a/net/netfilter/xt_RATEEST.c b/net/netfilter/xt_RATEEST.c
index 498b54fd04d7..141c295191f6 100644
--- a/net/netfilter/xt_RATEEST.c
+++ b/net/netfilter/xt_RATEEST.c@@ -39,23 +39,31 @@ static void xt_rateest_hash_insert(struct xt_rateest *est) hlist_add_head(&est->list, &rateest_hash[h]); } -struct xt_rateest *xt_rateest_lookup(const char *name) +static struct xt_rateest *__xt_rateest_lookup(const char *name) { struct xt_rateest *est; unsigned int h; h = xt_rateest_hash(name); - mutex_lock(&xt_rateest_mutex); hlist_for_each_entry(est, &rateest_hash[h], list) { if (strcmp(est->name, name) == 0) { est->refcnt++; - mutex_unlock(&xt_rateest_mutex); return est; } } - mutex_unlock(&xt_rateest_mutex); + return NULL; } + +struct xt_rateest *xt_rateest_lookup(const char *name) +{ + struct xt_rateest *est; + + mutex_lock(&xt_rateest_mutex); + est = __xt_rateest_lookup(name); + mutex_unlock(&xt_rateest_mutex); + return est; +} EXPORT_SYMBOL_GPL(xt_rateest_lookup); void xt_rateest_put(struct xt_rateest *est)
@@ -100,8 +108,10 @@ static int xt_rateest_tg_checkentry(const struct xt_tgchk_param *par) net_get_random_once(&jhash_rnd, sizeof(jhash_rnd)); - est = xt_rateest_lookup(info->name); + mutex_lock(&xt_rateest_mutex); + est = __xt_rateest_lookup(info->name); if (est) { + mutex_unlock(&xt_rateest_mutex); /* * If estimator parameters are specified, they must match the * existing estimator.
@@ -139,11 +149,13 @@ static int xt_rateest_tg_checkentry(const struct xt_tgchk_param *par) info->est = est; xt_rateest_hash_insert(est); + mutex_unlock(&xt_rateest_mutex); return 0; err2: kfree(est); err1: + mutex_unlock(&xt_rateest_mutex); return ret; }
--
2.11.0