From patchwork Tue May 7 06:21:35 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Duoming Zhou X-Patchwork-Id: 13656312 X-Patchwork-Delegate: kuba@kernel.org Received: from zg8tmja5ljk3lje4ms43mwaa.icoremail.net (zg8tmja5ljk3lje4ms43mwaa.icoremail.net [209.97.181.73]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 8402976EEA; Tue, 7 May 2024 06:21:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.97.181.73 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715062911; cv=none; b=j2hMitbzqrt1RjhJFN2R86UnIAMnY0rLufSA6ZthZz5rfkyP7a9UE+tVU4RVk/mPmNVjnR/gcTQIvMaaCys89ZU6hJf3eFFLW8ajRMxKOUFeFY2UBUOrqKJcVCAQe3BHP639JVW6weDj9aGeQ/fvl1nd1A/UXPryC1H15xSyjAw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715062911; c=relaxed/simple; bh=YjkmmEfXWCaLJD7QxPp6Hwb51t98Ph3yh4aNnsAL6o0=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References; b=grntVDrxgMEdX/b+3FnOZN3RGZify52tD7ibDW9kYFc0wALrRWVnosWO3z6b4n9wMk0aF4IIV2buJ7vfTKsL7G8J+2JXPkTv3BU58JJDPAu2Zk+1ruoOcQfJo5j3zMfOLnrwXOs5B477mzHztBvy7uxEu8sBLIsmf3eNSWxynWo= 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=209.97.181.73 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_KCgAXo7BwyDlmK4UzAA--.6419S2; Tue, 07 May 2024 14:21:38 +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 2/4] ax25: Fix reference count leak issues of ax25_dev Date: Tue, 7 May 2024 14:21:35 +0800 Message-Id: <873a4f366024c151442c7306902b16957f623c11.1715062582.git.duoming@zju.edu.cn> X-Mailer: git-send-email 2.17.1 In-Reply-To: References: X-CM-TRANSID: cS_KCgAXo7BwyDlmK4UzAA--.6419S2 X-Coremail-Antispam: 1UD129KBjvJXoW7ZF4rXr4Utr1rur1UtFykGrg_yoW8KF1kpF Wa9FW5ArWktr4Utr4DWr1xWr1jvryqk393AryUuF1Ikw1rX3sxJr1rtr4DXryUGryfZF48 Xw17Wrs8ZFWkuaDanT9S1TB71UUUUUDqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUGv14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26w1j6s0DM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26rxl 6s0DM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s 0DM2vj628EF7xvwVC0I7IYx2IY6xkF7I0E14v26rxl6s0q628EF7xvwVC0I7IYx2IY67AK xVWDJVCq3VCjxxvEa2IrM2vj628EF7xvwVC0I7IYx2IY6xkF7I0E14v26rxl6s0q628EF7 xvwVC2z280aVAFwI0_GcCE3s0E7I0Y6sxI4wAa7VA2z4x0Y4vE2Ix0cI8IcVCY1x0267AK xVW0oVCq3VCjxxvEa2IrM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c 02F40Ex7xfMcIj6xIIjxv20xvE14v26r1Y6r17McIj6I8E87Iv67AKxVW8JVWxJwAm72CE 4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7M4 IIrI8v6xkF7I0E8cxan2IY04v7MxkF7I0En4kS14v26r4a6rW5MxkIecxEwVAFwVW8AwCF 04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r 18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vI r41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr 1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r4j6F4UMIIF0xvE x4A2jsIEc7CjxVAFwI0_Gr1j6F4UJbIYCTnIWIevJa73UjIFyTuYvjfUj7KsUUUUU X-CM-SenderInfo: qssqjiasttq6lmxovvfxof0/1tbiAwMOAWY4-AkEPQBUsJ Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: X-Patchwork-Delegate: kuba@kernel.org The ax25_addr_ax25dev() and ax25_dev_device_down() exist a reference count leak issue of the object "ax25_dev". Memory leak issue in ax25_addr_ax25dev(): The reference count of the object "ax25_dev" can be increased multiple times in ax25_addr_ax25dev(). This will cause a memory leak so far. Memory leak issues in ax25_dev_device_down(): The reference count of ax25_dev is set to 1 in ax25_dev_device_up() and then increase the reference count when ax25_dev is added to ax25_dev_list. As a result, the reference count of ax25_dev is 2. But when the device is shutting down. The ax25_dev_device_down() drops the reference count once or twice depending on if we goto unlock_put or not, which will cause memory leak. As for the issue of ax25_addr_ax25dev(), it is impossible for one pointer to be on a list twice. So add a break in ax25_addr_ax25dev(). As for the issue of ax25_dev_device_down(), increase the reference count of ax25_dev once in ax25_dev_device_up() and decrease the reference count of ax25_dev after it is removed from the ax25_dev_list. 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 ax25_dev as a separate update steps. net/ax25/ax25_dev.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/net/ax25/ax25_dev.c b/net/ax25/ax25_dev.c index d4e1e36a6a8..6a572fe1046 100644 --- a/net/ax25/ax25_dev.c +++ b/net/ax25/ax25_dev.c @@ -38,6 +38,7 @@ ax25_dev *ax25_addr_ax25dev(ax25_address *addr) if (ax25cmp(addr, (const ax25_address *)ax25_dev->dev->dev_addr) == 0) { res = ax25_dev; ax25_dev_hold(ax25_dev); + break; } spin_unlock_bh(&ax25_dev_lock); @@ -90,7 +91,6 @@ void ax25_dev_device_up(struct net_device *dev) list_add(&ax25_dev->list, &ax25_dev_list); dev->ax25_ptr = ax25_dev; spin_unlock_bh(&ax25_dev_lock); - ax25_dev_hold(ax25_dev); ax25_register_dev_sysctl(ax25_dev); } @@ -131,7 +131,6 @@ void ax25_dev_device_down(struct net_device *dev) unlock_put: dev->ax25_ptr = NULL; spin_unlock_bh(&ax25_dev_lock); - ax25_dev_put(ax25_dev); netdev_put(dev, &ax25_dev->dev_tracker); ax25_dev_put(ax25_dev); }