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Received: from mga04.intel.com ([192.55.52.120]) by merlin.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1csmxZ-0006PG-OT for linux-arm-kernel@lists.infradead.org; Tue, 28 Mar 2017 08:58:38 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=intel.com; i=@intel.com; q=dns/txt; s=intel; t=1490691517; x=1522227517; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=y2+fhvPiPGKFRBFuLn5TI5PrBXBByV41pFbEUJYfDsk=; b=i8krTELXm7i7z0/q3cMYjBn5q6Mb6sXKrG8g0VcuJAIRSwlcCjy3JdV2 c08lZv1niixzljssx9q0Xx9VRAmhtg==; Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 Mar 2017 01:58:16 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.36,236,1486454400"; d="scan'208";a="81798224" Received: from unknown (HELO elena-ThinkPad-X230.ger.corp.intel.com) ([10.249.44.56]) by fmsmga006.fm.intel.com with ESMTP; 28 Mar 2017 01:58:09 -0700 From: Elena Reshetova To: netdev@vger.kernel.org Subject: [PATCH 12/16] drivers, net, ppp: convert asyncppp.refcnt from atomic_t to refcount_t Date: Tue, 28 Mar 2017 11:56:39 +0300 Message-Id: <1490691403-4016-13-git-send-email-elena.reshetova@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1490691403-4016-1-git-send-email-elena.reshetova@intel.com> References: <1490691403-4016-1-git-send-email-elena.reshetova@intel.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170328_045837_991945_784214F7 X-CRM114-Status: GOOD ( 11.65 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: peterz@infradead.org, matanb@mellanox.com, paulus@samba.org, Elena Reshetova , nbd@openwrt.org, linux-rdma@vger.kernel.org, saeedm@mellanox.com, ganeshgr@chelsio.com, Hans Liljestrand , David Windsor , keescook@chromium.org, j@w1.fi, ajk@comnets.uni-bremen.de, leonro@mellanox.com, matthias.bgg@gmail.com, linux-hams@vger.kernel.org, kvalo@codeaurora.org, blogic@openwrt.org, linux-arm-kernel@lists.infradead.org, linux-ppp@vger.kernel.org, yishaih@mellanox.com, linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP 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 --- drivers/net/ppp/ppp_async.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/net/ppp/ppp_async.c b/drivers/net/ppp/ppp_async.c index feb9569..2d08f7e 100644 --- a/drivers/net/ppp/ppp_async.c +++ b/drivers/net/ppp/ppp_async.c @@ -69,7 +69,7 @@ struct asyncppp { struct tasklet_struct tsk; - atomic_t refcnt; + refcount_t refcnt; struct semaphore dead_sem; struct ppp_channel chan; /* interface to generic ppp layer */ unsigned char obuf[OBUFSIZE]; @@ -140,14 +140,14 @@ static struct asyncppp *ap_get(struct tty_struct *tty) read_lock(&disc_data_lock); ap = tty->disc_data; if (ap != NULL) - atomic_inc(&ap->refcnt); + refcount_inc(&ap->refcnt); read_unlock(&disc_data_lock); return ap; } static void ap_put(struct asyncppp *ap) { - if (atomic_dec_and_test(&ap->refcnt)) + if (refcount_dec_and_test(&ap->refcnt)) up(&ap->dead_sem); } @@ -185,7 +185,7 @@ ppp_asynctty_open(struct tty_struct *tty) skb_queue_head_init(&ap->rqueue); tasklet_init(&ap->tsk, ppp_async_process, (unsigned long) ap); - atomic_set(&ap->refcnt, 1); + refcount_set(&ap->refcnt, 1); sema_init(&ap->dead_sem, 0); ap->chan.private = ap; @@ -234,7 +234,7 @@ ppp_asynctty_close(struct tty_struct *tty) * our channel ops (i.e. ppp_async_send/ioctl) are in progress * by the time it returns. */ - if (!atomic_dec_and_test(&ap->refcnt)) + if (!refcount_dec_and_test(&ap->refcnt)) down(&ap->dead_sem); tasklet_kill(&ap->tsk);