From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DE67AC28EBD for ; Sun, 9 Jun 2019 17:02:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B7982206DF for ; Sun, 9 Jun 2019 17:02:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560099724; bh=lxsZoQAD5/d/XAwBegYHEkjc7o8O926s15fiCs88V0o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=WT1IQGIMirHIEaVkRvXcSvbBsym1XwOSdOlUoJO5SsnKAoSbL7sX1aPRftqyP9Y31 NZOdVGtdJ4y9w0RQw5PTn7tJqsnIM2a9CR+NSeHepetQhOzh1bvyVUxp8ivpuzZm1+ 38lcgJwPIi24+ySkFdduZcXfv/VKQZrSlc3zZuL8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388192AbfFIRCE (ORCPT ); Sun, 9 Jun 2019 13:02:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:39682 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388169AbfFIRCB (ORCPT ); Sun, 9 Jun 2019 13:02:01 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D6A35206DF; Sun, 9 Jun 2019 17:02:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560099721; bh=lxsZoQAD5/d/XAwBegYHEkjc7o8O926s15fiCs88V0o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ozN9H2g5jABcCjCRPbFUqtfvOZBdwFBATjp680BQz7nCHD/BQm7B2tixLvBtS4EBS Q8zsPkcsKY+WdfrCwHQksS8iKkGtfloUyYE3Do+tsnFVbKt2ewjgLr/Y03zcy5hZlD /2yNioWV8oeroqL/T6QDcNJzk+urpvfo1opuH2e0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Kalle Valo , Sasha Levin Subject: [PATCH 4.4 099/241] brcm80211: potential NULL dereference in brcmf_cfg80211_vndr_cmds_dcmd_handler() Date: Sun, 9 Jun 2019 18:40:41 +0200 Message-Id: <20190609164150.652739731@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190609164147.729157653@linuxfoundation.org> References: <20190609164147.729157653@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Upstream commit e025da3d7aa4770bb1d1b3b0aa7cc4da1744852d ] If "ret_len" is negative then it could lead to a NULL dereference. The "ret_len" value comes from nl80211_vendor_cmd(), if it's negative then we don't allocate the "dcmd_buf" buffer. Then we pass "ret_len" to brcmf_fil_cmd_data_set() where it is cast to a very high u32 value. Most of the functions in that call tree check whether the buffer we pass is NULL but there are at least a couple places which don't such as brcmf_dbg_hex_dump() and brcmf_msgbuf_query_dcmd(). We memcpy() to and from the buffer so it would result in a NULL dereference. The fix is to change the types so that "ret_len" can't be negative. (If we memcpy() zero bytes to NULL, that's a no-op and doesn't cause an issue). Fixes: 1bacb0487d0e ("brcmfmac: replace cfg80211 testmode with vendor command") Signed-off-by: Dan Carpenter Signed-off-by: Kalle Valo Signed-off-by: Sasha Levin --- drivers/net/wireless/brcm80211/brcmfmac/vendor.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/brcm80211/brcmfmac/vendor.c b/drivers/net/wireless/brcm80211/brcmfmac/vendor.c index 8eff2753abade..d493021f60318 100644 --- a/drivers/net/wireless/brcm80211/brcmfmac/vendor.c +++ b/drivers/net/wireless/brcm80211/brcmfmac/vendor.c @@ -35,9 +35,10 @@ static int brcmf_cfg80211_vndr_cmds_dcmd_handler(struct wiphy *wiphy, struct brcmf_if *ifp; const struct brcmf_vndr_dcmd_hdr *cmdhdr = data; struct sk_buff *reply; - int ret, payload, ret_len; + unsigned int payload, ret_len; void *dcmd_buf = NULL, *wr_pointer; u16 msglen, maxmsglen = PAGE_SIZE - 0x100; + int ret; if (len < sizeof(*cmdhdr)) { brcmf_err("vendor command too short: %d\n", len); @@ -65,7 +66,7 @@ static int brcmf_cfg80211_vndr_cmds_dcmd_handler(struct wiphy *wiphy, brcmf_err("oversize return buffer %d\n", ret_len); ret_len = BRCMF_DCMD_MAXLEN; } - payload = max(ret_len, len) + 1; + payload = max_t(unsigned int, ret_len, len) + 1; dcmd_buf = vzalloc(payload); if (NULL == dcmd_buf) return -ENOMEM; -- 2.20.1