From patchwork Tue May 7 06:21:54 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Duoming Zhou X-Patchwork-Id: 13656313 X-Patchwork-Delegate: kuba@kernel.org Received: from azure-sdnproxy.icoremail.net (azure-sdnproxy.icoremail.net [207.46.229.174]) by smtp.subspace.kernel.org (Postfix) with ESMTP id A29EF73165; Tue, 7 May 2024 06:22:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=207.46.229.174 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715062929; cv=none; b=mkma6Pkpn2QhCUYrWdmTGvcu09IF1ounjmUCxZWzeD9QWDuzYaPtkPYQJEa5BnQkTV/wmttC1J51CUzHyAdpWc5P1qMcN7JT/upTIBgwAgTTFV/nqRc3PeDLXb12g+UZRKSDF9t4uSdsmilHOmbrieA9W4hEekzrt40E6onsP3U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715062929; c=relaxed/simple; bh=5eM5W6ze1j1mLPSQUbYA7MyvceG+JiOuYyGAGTYb/88=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References; b=FOuKN6SxtENBONW2xUgfBMoW2LsSgpsgiGtkvShAiR1Gdvf+20HexZFHIk0rkL1u7/3cRJWqqTM+yEayHOo3lamCp+xl3w8eKAWzo3XzXSq/9wKPClJUmkwTA3BOxrQ0uk2XoKyaXiZOs8OmVGNhSJ1bh7mAMa4EpXsOIZSvBe4= 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=207.46.229.174 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 [221.192.179.90]) by mail-app4 (Coremail) with SMTP id cS_KCgBX5bKCyDlmv4YzAA--.26135S2; Tue, 07 May 2024 14:21:56 +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, horms@kernel.org, Markus.Elfring@web.de, dan.carpenter@linaro.org, lars@oddbit.com, Duoming Zhou Subject: [PATCH RESEND net v4 3/4] ax25: Fix reference count leak issues of net_device Date: Tue, 7 May 2024 14:21:54 +0800 Message-Id: <02697d01b0d95859a9caf45f6b37af2d2b9959d8.1715062582.git.duoming@zju.edu.cn> X-Mailer: git-send-email 2.17.1 In-Reply-To: References: X-CM-TRANSID: cS_KCgBX5bKCyDlmv4YzAA--.26135S2 X-Coremail-Antispam: 1UD129KBjvJXoW7WFyxZry8AFy8Gry3XF18Xwb_yoW8GrWUpF W2gFW3ArZ7Jr1DGr4DWr97Wr10vryq93yrur15u3WIk3s5X3sxJryrKrWDXry7KrW3ZF18 u347Wrs5uF1kZaDanT9S1TB71UUUUUDqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUGm14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26w1j6s0DM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26rxl 6s0DM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s 0DM2vj628EF7xvwVC0I7IYx2IY6xkF7I0E14v26rxl6s0q628EF7xvwVC0I7IYx2IY67AK xVWDJVCq3VCjxxvEa2IrM2vj628EF7xvwVC0I7IYx2IY6xkF7I0E14v26rxl6s0q628EF7 xvwVC2z280aVAFwI0_GcCE3s0E7I0Y6sxI4wAa7VA2z4x0Y4vE2Ix0cI8IcVCY1x0267AK xVW0oVCq3VCjxxvEa2IrM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c 02F40Ex7xfMcIj6xIIjxv20xvE14v26r1Y6r17McIj6I8E87Iv67AKxVW8JVWxJwAm72CE 4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7M4 IIrI8v6xkF7I0E8cxan2IY04v7MxkF7I0En4kS14v26r4a6rW5MxkIecxEwVAFwVW8AwCF 04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r 18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vI r41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Cr0_Gr 1UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVW8JVWxJwCI42IY 6I8E87Iv6xkF7I0E14v26r4UJVWxJrUvcSsGvfC2KfnxnUUI43ZEXa7VUUxwIDUUUUU== X-CM-SenderInfo: qssqjiasttq6lmxovvfxof0/1tbiAwMOAWY4-AkEPQBWsL Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: X-Patchwork-Delegate: kuba@kernel.org 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 --- Changes in v4: - Make the fix procedure of net_device as a separate update steps. 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 6a572fe1046..05e556cdc2b 100644 --- a/net/ax25/ax25_dev.c +++ b/net/ax25/ax25_dev.c @@ -120,15 +120,9 @@ void ax25_dev_device_down(struct net_device *dev) list_for_each_entry(s, &ax25_dev_list, list) { if (s == ax25_dev) { list_del(&s->list); - goto unlock_put; + break; } } - dev->ax25_ptr = NULL; - spin_unlock_bh(&ax25_dev_lock); - ax25_dev_put(ax25_dev); - return; - -unlock_put: dev->ax25_ptr = NULL; spin_unlock_bh(&ax25_dev_lock); netdev_put(dev, &ax25_dev->dev_tracker);