From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:43078 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1164244AbeE1KyD (ORCPT ); Mon, 28 May 2018 06:54:03 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Arnd Bergmann , Philipp Zabel , Sasha Levin Subject: [PATCH 4.14 250/496] gpu: ipu-v3: prg: avoid possible array underflow Date: Mon, 28 May 2018 12:00:35 +0200 Message-Id: <20180528100330.420599863@linuxfoundation.org> In-Reply-To: <20180528100319.498712256@linuxfoundation.org> References: <20180528100319.498712256@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Arnd Bergmann [ Upstream commit 746d024c3211813946b319411aeb2b47767f8fb0 ] gcc-8 reports that we access an array with a negative index in an error case: drivers/gpu/ipu-v3/ipu-prg.c: In function 'ipu_prg_channel_disable': drivers/gpu/ipu-v3/ipu-prg.c:252:43: error: array subscript -22 is below array bounds of 'struct ipu_prg_channel[3]' [-Werror=array-bounds] This moves the range check in front of the first time that variable gets used. Signed-off-by: Arnd Bergmann Signed-off-by: Philipp Zabel Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/ipu-v3/ipu-prg.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) --- a/drivers/gpu/ipu-v3/ipu-prg.c +++ b/drivers/gpu/ipu-v3/ipu-prg.c @@ -252,10 +252,14 @@ void ipu_prg_channel_disable(struct ipuv { int prg_chan = ipu_prg_ipu_to_prg_chan(ipu_chan->num); struct ipu_prg *prg = ipu_chan->ipu->prg_priv; - struct ipu_prg_channel *chan = &prg->chan[prg_chan]; + struct ipu_prg_channel *chan; u32 val; - if (!chan->enabled || prg_chan < 0) + if (prg_chan < 0) + return; + + chan = &prg->chan[prg_chan]; + if (!chan->enabled) return; clk_prepare_enable(prg->clk_ipg); @@ -282,13 +286,15 @@ int ipu_prg_channel_configure(struct ipu { int prg_chan = ipu_prg_ipu_to_prg_chan(ipu_chan->num); struct ipu_prg *prg = ipu_chan->ipu->prg_priv; - struct ipu_prg_channel *chan = &prg->chan[prg_chan]; + struct ipu_prg_channel *chan; u32 val; int ret; if (prg_chan < 0) return prg_chan; + chan = &prg->chan[prg_chan]; + if (chan->enabled) { ipu_pre_update(prg->pres[chan->used_pre], *eba); return 0;