From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-pf0-f176.google.com ([209.85.192.176]:36025 "EHLO mail-pf0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750780AbdEIXXg (ORCPT ); Tue, 9 May 2017 19:23:36 -0400 Received: by mail-pf0-f176.google.com with SMTP id m17so7007583pfg.3 for ; Tue, 09 May 2017 16:23:36 -0700 (PDT) Date: Tue, 9 May 2017 16:23:34 -0700 From: Kees Cook To: netdev@vger.kernel.org Cc: Kalle Valo , libertas-dev@lists.infradead.org, linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, Daniel Micay Subject: [PATCH] libertas: Avoid reading past end of buffer Message-ID: <20170509232334.GA55070@beast> (sfid-20170510_012412_402148_35A9A28C) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-wireless-owner@vger.kernel.org List-ID: Using memcpy() from a string that is shorter than the length copied means the destination buffer is being filled with arbitrary data from the kernel rodata segment. Instead, use strncpy() which will fill the trailing bytes with zeros. Additionally adjust indentation to keep checkpatch.pl happy. This was found with the future CONFIG_FORTIFY_SOURCE feature. Cc: Daniel Micay Signed-off-by: Kees Cook --- drivers/net/wireless/marvell/libertas/mesh.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/marvell/libertas/mesh.c b/drivers/net/wireless/marvell/libertas/mesh.c index d0c881dd5846..d0b1948ca242 100644 --- a/drivers/net/wireless/marvell/libertas/mesh.c +++ b/drivers/net/wireless/marvell/libertas/mesh.c @@ -1177,9 +1177,9 @@ void lbs_mesh_ethtool_get_strings(struct net_device *dev, switch (stringset) { case ETH_SS_STATS: for (i = 0; i < MESH_STATS_NUM; i++) { - memcpy(s + i * ETH_GSTRING_LEN, - mesh_stat_strings[i], - ETH_GSTRING_LEN); + strncpy(s + i * ETH_GSTRING_LEN, + mesh_stat_strings[i], + ETH_GSTRING_LEN); } break; } -- 2.7.4 -- Kees Cook Pixel Security