From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753774AbdCPSYS (ORCPT ); Thu, 16 Mar 2017 14:24:18 -0400 Received: from mga11.intel.com ([192.55.52.93]:9412 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753645AbdCPSYQ (ORCPT ); Thu, 16 Mar 2017 14:24:16 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.36,173,1486454400"; d="scan'208";a="76262556" From: Elena Reshetova To: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org, davem@davemloft.net, jmorris@namei.org, kaber@trash.net, yoshfuji@linux-ipv6.org, steffen.klassert@secunet.com, kuznet@ms2.inr.ac.ru, peterz@infradead.org, keescook@chromium.org, Elena Reshetova , Hans Liljestrand , David Windsor Subject: [PATCH 9/9] net, ipv4: convert fib_info.fib_clntref from atomic_t to refcount_t Date: Thu, 16 Mar 2017 20:23:31 +0200 Message-Id: <1489688611-4542-10-git-send-email-elena.reshetova@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1489688611-4542-1-git-send-email-elena.reshetova@intel.com> References: <1489688611-4542-1-git-send-email-elena.reshetova@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor --- include/net/ip_fib.h | 7 ++++--- net/ipv4/fib_semantics.c | 2 +- net/ipv4/fib_trie.c | 2 +- 3 files changed, 6 insertions(+), 5 deletions(-) diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h index 368bb40..55d2694 100644 --- a/include/net/ip_fib.h +++ b/include/net/ip_fib.h @@ -23,6 +23,7 @@ #include #include #include +#include struct fib_config { u8 fc_dst_len; @@ -105,7 +106,7 @@ struct fib_info { struct hlist_node fib_lhash; struct net *fib_net; int fib_treeref; - atomic_t fib_clntref; + refcount_t fib_clntref; unsigned int fib_flags; unsigned char fib_dead; unsigned char fib_protocol; @@ -407,12 +408,12 @@ void free_fib_info(struct fib_info *fi); static inline void fib_info_hold(struct fib_info *fi) { - atomic_inc(&fi->fib_clntref); + refcount_inc(&fi->fib_clntref); } static inline void fib_info_put(struct fib_info *fi) { - if (atomic_dec_and_test(&fi->fib_clntref)) + if (refcount_dec_and_test(&fi->fib_clntref)) free_fib_info(fi); } diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index 317026a..9c361bd 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -1174,7 +1174,7 @@ struct fib_info *fib_create_info(struct fib_config *cfg) } fi->fib_treeref++; - atomic_inc(&fi->fib_clntref); + refcount_set(&fi->fib_clntref, 1); spin_lock_bh(&fib_info_lock); hlist_add_head(&fi->fib_hash, &fib_info_hash[fib_info_hashfn(fi)]); diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c index 2f0d823..d3bbe6e 100644 --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -1543,7 +1543,7 @@ int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, } if (!(fib_flags & FIB_LOOKUP_NOREF)) - atomic_inc(&fi->fib_clntref); + refcount_inc(&fi->fib_clntref); res->prefixlen = KEYLENGTH - fa->fa_slen; res->nh_sel = nhsel; -- 2.7.4