Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756854AbdLVKsZ (ORCPT ); Fri, 22 Dec 2017 05:48:25 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:33592 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756827AbdLVIuN (ORCPT ); Fri, 22 Dec 2017 03:50:13 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Rasesh Mody , "David S. Miller" , Sasha Levin Subject: [PATCH 4.4 24/78] bna: integer overflow bug in debugfs Date: Fri, 22 Dec 2017 09:46:05 +0100 Message-Id: <20171222084559.664427612@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20171222084556.909780563@linuxfoundation.org> References: <20171222084556.909780563@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1255 Lines: 38 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Carpenter [ Upstream commit 13e2d5187f6b965ba3556caedb914baf81b98ed2 ] We could allocate less memory than intended because we do: bnad->regdata = kzalloc(len << 2, GFP_KERNEL); The shift can overflow leading to a crash. This is debugfs code so the impact is very small. Fixes: 7afc5dbde091 ("bna: Add debugfs interface.") Signed-off-by: Dan Carpenter Acked-by: Rasesh Mody Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/brocade/bna/bnad_debugfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/net/ethernet/brocade/bna/bnad_debugfs.c +++ b/drivers/net/ethernet/brocade/bna/bnad_debugfs.c @@ -324,7 +324,7 @@ bnad_debugfs_write_regrd(struct file *fi return PTR_ERR(kern_buf); rc = sscanf(kern_buf, "%x:%x", &addr, &len); - if (rc < 2) { + if (rc < 2 || len > UINT_MAX >> 2) { netdev_warn(bnad->netdev, "failed to read user buffer\n"); kfree(kern_buf); return -EINVAL;