From nobody Wed Dec 17 05:50:12 2025 Received: from zg8tmtyylji0my4xnjeumjiw.icoremail.net (zg8tmtyylji0my4xnjeumjiw.icoremail.net [162.243.161.220]) by smtp.subspace.kernel.org (Postfix) with ESMTP id B023E13CF83; Thu, 9 May 2024 01:56:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=162.243.161.220 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715219817; cv=none; b=gNZhCAa7F9EfEWYD3VSZ8iec/+agD5igCu8SgOR21z33Te5qaFFaNhpCJ2EfM7UOpGrCdO56uXzomyoLfMw4zrguo38T5SirAmOZ5QWOiLL1qODq9i6a2VVq/LKLa9MWZ6U6Yt6DDt51GBFVE33P0ElTprcNNkDhcRZXjCXe98g= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715219817; c=relaxed/simple; bh=Lli1kLaNsVAUfmSU8DR3wNA4Occs19lWcrVhE1EaVvs=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References; b=dghimGXJvMT/yMLQZoiI4LOpERdQONS93D57MpK/ulEJWUevVV5X4pkW3MZPVsW/p0LV2VRpi3NMc1JOgP6FYzJeIOFrZALfPIuGeGEBw7A+iD6B1mUns/d60ynotGB8O7d4weQd/vZuIgbJ/+YIq+XVvpzxe9l2mwftHkjNsnc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=zju.edu.cn; spf=pass smtp.mailfrom=zju.edu.cn; arc=none smtp.client-ip=162.243.161.220 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=zju.edu.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zju.edu.cn Received: from ubuntu.localdomain (unknown [221.192.180.131]) by mail-app4 (Coremail) with SMTP id cS_KCgDnc7FWLTxmNkpMAA--.45924S2; Thu, 09 May 2024 09:56:40 +0800 (CST) From: Duoming Zhou To: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-hams@vger.kernel.org, pabeni@redhat.com, kuba@kernel.org, edumazet@google.com, davem@davemloft.net, jreuter@yaina.de, dan.carpenter@linaro.org, Duoming Zhou Subject: [PATCH net v6 3/3] ax25: Fix reference count leak issues of net_device Date: Thu, 9 May 2024 09:56:36 +0800 Message-Id: <4890e260622ae06922a838f063d5dfd385931cda.1715219007.git.duoming@zju.edu.cn> X-Mailer: git-send-email 2.17.1 In-Reply-To: References: X-CM-TRANSID: cS_KCgDnc7FWLTxmNkpMAA--.45924S2 X-Coremail-Antispam: 1UD129KBjvJXoW7WFyxZry8AFy8Gry3XF18Xwb_yoW8JFyrpF W2gFW3ArZ7Jr1DJr4DWr97Wr15Zryq93yrCr15u3WSk3s5X3sxJryrKrWUXry7KrWfZF18 u347Wrs8uF4kZaUanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUU9C14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26w1j6s0DM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26F4U JVW0owA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oV Cq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0 I7IYx2IY67AKxVWUAVWUtwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r 4UM4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628v n2kIc2xKxwCY1x0262kKe7AKxVWUtVW8ZwCY02Avz4vE14v_KwCF04k20xvY0x0EwIxGrw CFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE 14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2 IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxK x2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI 0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x0JUlYL9UUUUU= X-CM-SenderInfo: qssqjiasttq6lmxovvfxof0/1tbiAwIQAWY7nwoGrwANs8 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" The ax25_dev_device_down() exists reference count leak issues of the object "net_device". When the ax25 device is shutting down. The ax25_dev_device_down() drops the reference count of net_device one or zero times depending on if we goto unlock_put or not, which will cause memory leak. In order to solve the above issue, decrease the reference count of net_device after dev->ax25_ptr is set to null. Fixes: d01ffb9eee4a ("ax25: add refcount in ax25_dev to avoid UAF bugs") Suggested-by: Dan Carpenter Signed-off-by: Duoming Zhou --- net/ax25/ax25_dev.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) diff --git a/net/ax25/ax25_dev.c b/net/ax25/ax25_dev.c index 37150f766a0..f37b143d69b 100644 --- a/net/ax25/ax25_dev.c +++ b/net/ax25/ax25_dev.c @@ -121,15 +121,9 @@ void ax25_dev_device_down(struct net_device *dev) list_for_each_entry(s, &ax25_dev_list, list) { if (s =3D=3D ax25_dev) { list_del(&s->list); - goto unlock_put; + break; } } - dev->ax25_ptr =3D NULL; - spin_unlock_bh(&ax25_dev_lock); - ax25_dev_put(ax25_dev); - return; - -unlock_put: dev->ax25_ptr =3D NULL; spin_unlock_bh(&ax25_dev_lock); netdev_put(dev, &ax25_dev->dev_tracker); --=20 2.17.1