From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELvh0tezxpyp10eKKYUx07jHUkSrDDCnpxlNL+h22x5zColWp74rIxsAJL9vZEVfnlCSRC0/ ARC-Seal: i=1; a=rsa-sha256; t=1519410895; cv=none; d=google.com; s=arc-20160816; b=bEEQmLHMq4p6TquKrFgwmHuJ4vaNYgweXmTDB+Fw1Mkz8se+bo+9psEp1qFA9rBzuX GIVu3MfpEmX7yvh2Z8I5NlwDFQ1lzOMc3ua0W2QwF2BG0H3jnsA4reqN1z4OGDRyUDM3 lpjl+WNm9QtQoFKgVGP/ijRkE+aMJ7xUbkpyH95iHYVjcn/NvyrfOCp5vwREpnuKpzz6 1JaMzXDM/060r+OilTggJgq9YGez5BIpXHGa+SW9VqYCsfQvOP4M7vg29HxwiMyNwMRj C7akPh7TkJYSUEx5+fzBfbkk4UTpHamif7broJ7xfhdL2xA8AqOW5dcHVkK+VXuSq1EP AcQA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=jh0U38cCoQjJu2IZncDFmTKoFM0+2W9vroPhz6vGAos=; b=Dgr/ALgPqJi+X53rsAynyk8FrMATRbuIfhMHd2S96PuF2SBiYs2Jl034B7sDkqW40D 5ZSZ73OuZNaPoZght7YrFYbhPRsltcGMl4sX5NUqv4ROZyx2ZLfcK63MTVzei+v8Uzvj werXjDgkeEWB/UGCb4CjcTMacd+ejmnP3g5KDLIGxxMZEWW9uRcPu98jzrcHeUab5mrR /f+ARdXX7bQ8AaWQNURQ2QOEPny6wG0Cxvi9oBL+n3UrKvPgWguO388eq8fzVPyeGcfK hBeyqu35FUxlgqr/hQiu4Gy4NdeiLhYLHluRJQXY3WsxvEY02M3tVUWPTQOo9anZrp7h NDVQ== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Gustavo A. R. Silva" , Ludovic Desroches , Vinod Koul , Sasha Levin Subject: [PATCH 4.4 051/193] dmaengine: at_hdmac: fix potential NULL pointer dereference in atc_prep_dma_interleaved Date: Fri, 23 Feb 2018 19:24:44 +0100 Message-Id: <20180223170334.016821770@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180223170325.997716448@linuxfoundation.org> References: <20180223170325.997716448@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1593217798955458934?= X-GMAIL-MSGID: =?utf-8?q?1593217798955458934?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Gustavo A. R. Silva" [ Upstream commit 62a277d43d47e74972de44d33bd3763e31992414 ] _xt_ is being dereferenced before it is null checked, hence there is a potential null pointer dereference. Fix this by moving the pointer dereference after _xt_ has been null checked. This issue was detected with the help of Coccinelle. Fixes: 4483320e241c ("dmaengine: Use Pointer xt after NULL check.") Signed-off-by: Gustavo A. R. Silva Acked-by: Ludovic Desroches Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/dma/at_hdmac.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/dma/at_hdmac.c +++ b/drivers/dma/at_hdmac.c @@ -716,7 +716,7 @@ atc_prep_dma_interleaved(struct dma_chan unsigned long flags) { struct at_dma_chan *atchan = to_at_dma_chan(chan); - struct data_chunk *first = xt->sgl; + struct data_chunk *first; struct at_desc *desc = NULL; size_t xfer_count; unsigned int dwidth; @@ -728,6 +728,8 @@ atc_prep_dma_interleaved(struct dma_chan if (unlikely(!xt || xt->numf != 1 || !xt->frame_size)) return NULL; + first = xt->sgl; + dev_info(chan2dev(chan), "%s: src=%pad, dest=%pad, numf=%d, frame_size=%d, flags=0x%lx\n", __func__, &xt->src_start, &xt->dst_start, xt->numf,