From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2E6E31EEF7; Mon, 27 May 2024 19:30:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716838251; cv=none; b=X8y0e/0H2QnZN2T6bBoEVS7gEWzCnMqGwUzxSLExORgZ9AVqTQawuN6yPP7VaA/0cB7/gllxbxPYiLLKojbZoMQJA7C0KLCtY14p7aeegNcW7ssukzKhsz45Z4u9R8XmIgz61RQMUf4loLh5SsigmKAmR+gM50KKED3a31tOza8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716838251; c=relaxed/simple; bh=Fo0p1+PxisyUQ8V6tiOS5ddmRzV8q5kIo6NaOdbNza8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jQO677zFABqQYaPPkLmv1Cl1SjeB0N6+8Hvj9sbAwdhkI4sUjHSKAu+DvnHBDKYRt+ji/eAp9DQzK2RXvVl1lxUlai8UUHr0TObMZir9yh08QOtgivzQWJkQahub7BTVvagFYw1uOl7ghEbCCPuRt+T2AR0jGPzP3s0+Gs6BSbA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=W0T2+EV/; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="W0T2+EV/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 28289C2BBFC; Mon, 27 May 2024 19:30:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1716838250; bh=Fo0p1+PxisyUQ8V6tiOS5ddmRzV8q5kIo6NaOdbNza8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=W0T2+EV/bH8oJk9TW5Jtf84LYrBXMOfkk9Rj95uLixM319boWcLLnwfFyiQ99lN2E Z1HJ3H278X4KHjdsTYHpZsRDy3YZx89dMpVEM4XOHnPahQ694nv3TxO4vCkF9ugzax hz4KuwGDsyjW1vmkZTzHsU8bpw4PmNbu6KTsbeTM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dan Carpenter , Duoming Zhou , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.8 323/493] ax25: Fix reference count leak issue of net_device Date: Mon, 27 May 2024 20:55:25 +0200 Message-ID: <20240527185640.835474924@linuxfoundation.org> X-Mailer: git-send-email 2.45.1 In-Reply-To: <20240527185626.546110716@linuxfoundation.org> References: <20240527185626.546110716@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Duoming Zhou [ Upstream commit 36e56b1b002bb26440403053f19f9e1a8bc075b2 ] There is a reference count leak issue of the object "net_device" in ax25_dev_device_down(). 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 Reviewed-by: Dan Carpenter Link: https://lore.kernel.org/r/7ce3b23a40d9084657ba1125432f0ecc380cbc80.1715247018.git.duoming@zju.edu.cn Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ax25/ax25_dev.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/net/ax25/ax25_dev.c b/net/ax25/ax25_dev.c index 52ccc37d5687a..c9d55b99a7a57 100644 --- a/net/ax25/ax25_dev.c +++ b/net/ax25/ax25_dev.c @@ -118,15 +118,10 @@ 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); -- 2.43.0