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 65638C282DE for ; Wed, 22 May 2019 19:22:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3A944206BA for ; Wed, 22 May 2019 19:22:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558552945; bh=YzezW2Fba2Qpg5me27N4CVgznmETrqoWlEbAAN6ufFg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=hff70aXnVYX/kGfylGzKV72XoslZodZGxEk6h8IaKs3f6EJB6OpjV29tk0PyBgFOx yPpmbguhtTXqQMHsYYfzMRaaI92/o+arockhlqZ3hTAaPzPEl8jqJoMxTikWI7zNx2 /7hAnasF6g+PWHmBmFKkEUwQW580UTfZAihas+pI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730451AbfEVTWY (ORCPT ); Wed, 22 May 2019 15:22:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:43010 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730425AbfEVTWW (ORCPT ); Wed, 22 May 2019 15:22:22 -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 62724217F9; Wed, 22 May 2019 19:22:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558552941; bh=YzezW2Fba2Qpg5me27N4CVgznmETrqoWlEbAAN6ufFg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pwTMZgk6ttZZMmW8JGU6yTrDktklu8NQ8uWJm7tAtLBVtCtEmA4E/FulirrAVtHuK sLO/M27MT6BN9zzRiC86JfGys/rzGgsJ4L6Ihfgyz0tP0mQkDYS+ahpaR38bFf7t7X gm5b2DWnzFOKM+Nwc/SZAf6ITdfHNsGHk1TAxl3A= 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 5.1 041/375] brcm80211: potential NULL dereference in brcmf_cfg80211_vndr_cmds_dcmd_handler() Date: Wed, 22 May 2019 15:15:41 -0400 Message-Id: <20190522192115.22666-41-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190522192115.22666-1-sashal@kernel.org> References: <20190522192115.22666-1-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