From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:41514 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754599AbdFLPgC (ORCPT ); Mon, 12 Jun 2017 11:36:02 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thomas Petazzoni , Vinod Koul Subject: [PATCH 4.9 046/119] dmaengine: mv_xor_v2: handle mv_xor_v2_prep_sw_desc() error properly Date: Mon, 12 Jun 2017 17:25:08 +0200 Message-Id: <20170612152559.750297795@linuxfoundation.org> In-Reply-To: <20170612152556.601664278@linuxfoundation.org> References: <20170612152556.601664278@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Petazzoni commit eb8df543e444492328f506adffc7dfe94111f1bd upstream. The mv_xor_v2_prep_sw_desc() is called from a few different places in the driver, but we never take into account the fact that it might return NULL. This commit fixes that, ensuring that we don't panic if there are no more descriptors available. Fixes: 19a340b1a820 ("dmaengine: mv_xor_v2: new driver") Signed-off-by: Thomas Petazzoni Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman --- drivers/dma/mv_xor_v2.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/dma/mv_xor_v2.c +++ b/drivers/dma/mv_xor_v2.c @@ -389,6 +389,8 @@ mv_xor_v2_prep_dma_memcpy(struct dma_cha __func__, len, &src, &dest, flags); sw_desc = mv_xor_v2_prep_sw_desc(xor_dev); + if (!sw_desc) + return NULL; sw_desc->async_tx.flags = flags; @@ -443,6 +445,8 @@ mv_xor_v2_prep_dma_xor(struct dma_chan * __func__, src_cnt, len, &dest, flags); sw_desc = mv_xor_v2_prep_sw_desc(xor_dev); + if (!sw_desc) + return NULL; sw_desc->async_tx.flags = flags; @@ -491,6 +495,8 @@ mv_xor_v2_prep_dma_interrupt(struct dma_ container_of(chan, struct mv_xor_v2_device, dmachan); sw_desc = mv_xor_v2_prep_sw_desc(xor_dev); + if (!sw_desc) + return NULL; /* set the HW descriptor */ hw_descriptor = &sw_desc->hw_desc;