From patchwork Mon Feb 28 17:24:21 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 546980 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C6B59C4332F for ; Mon, 28 Feb 2022 18:11:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235145AbiB1SLk (ORCPT ); Mon, 28 Feb 2022 13:11:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60124 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241424AbiB1SJx (ORCPT ); Mon, 28 Feb 2022 13:09:53 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8940EB3E7D; Mon, 28 Feb 2022 09:50:01 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E348B6092A; Mon, 28 Feb 2022 17:49:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 08965C340E7; Mon, 28 Feb 2022 17:49:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1646070549; bh=QoV7j+7VjawEmBbE7tClEvzEIsDXiNYm9A4p/HtvrVQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oXCBRba6ckDMM6RmD0K8agfD+r7QWLcl9V1WAzT/p288OivGs5lbPx/AgFebrCK5r KXFJp6E2UunHn3vo4jMIvHZSAe1rqd717/6CWsfkPWnpJydPrIrrhR7oyCXcY4OJVp 7K0tWZ4wGFWzpFJjaFb5S2pPOKOC7RVQvMstOERU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Zhou Qingyang , Mark Brown , Sasha Levin Subject: [PATCH 5.16 099/164] spi: spi-zynq-qspi: Fix a NULL pointer dereference in zynq_qspi_exec_mem_op() Date: Mon, 28 Feb 2022 18:24:21 +0100 Message-Id: <20220228172408.772448140@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220228172359.567256961@linuxfoundation.org> References: <20220228172359.567256961@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Zhou Qingyang [ Upstream commit ab3824427b848da10e9fe2727f035bbeecae6ff4 ] In zynq_qspi_exec_mem_op(), kzalloc() is directly used in memset(), which could lead to a NULL pointer dereference on failure of kzalloc(). Fix this bug by adding a check of tmpbuf. This bug was found by a static analyzer. The analysis employs differential checking to identify inconsistent security operations (e.g., checks or kfrees) between two code paths and confirms that the inconsistent operations are not recovered in the current function or the callers, so they constitute bugs. Note that, as a bug found by static analysis, it can be a false positive or hard to trigger. Multiple researchers have cross-reviewed the bug. Builds with CONFIG_SPI_ZYNQ_QSPI=m show no new warnings, and our static analyzer no longer warns about this code. Fixes: 67dca5e580f1 ("spi: spi-mem: Add support for Zynq QSPI controller") Signed-off-by: Zhou Qingyang Link: https://lore.kernel.org/r/20211130172253.203700-1-zhou1615@umn.edu Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- drivers/spi/spi-zynq-qspi.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/spi/spi-zynq-qspi.c b/drivers/spi/spi-zynq-qspi.c index cfa222c9bd5e7..78f31b61a2aac 100644 --- a/drivers/spi/spi-zynq-qspi.c +++ b/drivers/spi/spi-zynq-qspi.c @@ -570,6 +570,9 @@ static int zynq_qspi_exec_mem_op(struct spi_mem *mem, if (op->dummy.nbytes) { tmpbuf = kzalloc(op->dummy.nbytes, GFP_KERNEL); + if (!tmpbuf) + return -ENOMEM; + memset(tmpbuf, 0xff, op->dummy.nbytes); reinit_completion(&xqspi->data_completion); xqspi->txbuf = tmpbuf;