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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 E97E9C282DC for ; Wed, 22 May 2019 19:47:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BAD512075B for ; Wed, 22 May 2019 19:47:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558554451; bh=YzezW2Fba2Qpg5me27N4CVgznmETrqoWlEbAAN6ufFg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ndiKrysEGLszgnrXAVKZDJ0WjmBZxRes3yW7Wme4TBcfvl1XIyOi+gBqKRuo9p7u5 fzZKOAk3fiiNV3yotdY+xvXEvh6vzW8xxgzpnTTuunXjLpH5f7RUZvWtfXINsROMS3 0YT+GACksbv1MrWQx18n1TMEgNs65LxV/CuNt/mI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731622AbfEVT1R (ORCPT ); Wed, 22 May 2019 15:27:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:49156 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731414AbfEVT1Q (ORCPT ); Wed, 22 May 2019 15:27:16 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0F65020879; Wed, 22 May 2019 19:27:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558553235; bh=YzezW2Fba2Qpg5me27N4CVgznmETrqoWlEbAAN6ufFg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dlfeFIe7CiVRKG8yYFyBQdUFavZrp1fq0YwpWvTAnwEpqh1r29ygwpljR7yfI7oj+ dcPIuL2hn0CeAOWNInPi4d4g5ZOwwFApT/xGyay+vFOOvLWYlyBymAMv7XtUdWuSSn uGI3M8Rbb6tWtzxhWb2ZnDQmsa8/nNlqcsbqWjZ0= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Dan Carpenter , Kalle Valo , Sasha Levin , linux-wireless@vger.kernel.org, brcm80211-dev-list.pdl@broadcom.com, brcm80211-dev-list@cypress.com, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 027/244] brcm80211: potential NULL dereference in brcmf_cfg80211_vndr_cmds_dcmd_handler() Date: Wed, 22 May 2019 15:22:53 -0400 Message-Id: <20190522192630.24917-27-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190522192630.24917-1-sashal@kernel.org> References: <20190522192630.24917-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Dan Carpenter [ 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/broadcom/brcm80211/brcmfmac/vendor.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/vendor.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/vendor.c index 8eff2753abade..d493021f60318 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/vendor.c +++ b/drivers/net/wireless/broadcom/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