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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 59DE7C43458 for ; Wed, 8 Jul 2026 21:03:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:MIME-Version:In-Reply-To: Content-Type:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Z1CB5IdWjzvBOUlE+iPQ9fW7uvQXz7VqFlbF5M+sM2w=; b=tnBYkwAAcUIr73MIV66rw7HOAl 0uM0BGBqoQ8QCRwOU6mD07R6o6Ui3yakGlxK9NLzgoUae9rvx3qq6MsRVl7oFhBUCin0tYy1lnZKV LKEP3d6UoocE8CtuyBJIKX4ybqPlhP3w1oMeVmirDX/bsP/aBDZKPwix9XkMJo4+Bl4ZKVu/e7qo2 OHjv4V9fd4OMjWhFyX0b9BqAVhIebBcJsjNDBAUA86I2KMA6Wc9Fl0qiCxv9UGReGAJUZoqqwFDZ2 0xgd1ZP9jW1Zb8PXuXl6UzHuVrMhsfaeW25X8s+D8Hk/pqcYTDY8uSjLtIABElHgrB3UXUKvtwZq7 BxcUZ/Eg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1whZQi-00000000Po2-0SsW; Wed, 08 Jul 2026 21:03:40 +0000 Received: from mail-northeuropeazlp170120005.outbound.protection.outlook.com ([2a01:111:f403:c200::5] helo=DUZPR83CU001.outbound.protection.outlook.com) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1whZQf-00000000PnZ-3amW for linux-arm-kernel@lists.infradead.org; Wed, 08 Jul 2026 21:03:39 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=sioAiGUi2hsh9gLt/mM8h7RpD2Zn+ixNpcfz6W9r26EmabkhKMsBJCyWO22GFXQRvaxFoIVZqxt2ecWpFctY9feBCbJfKAksAA3HWPKHAU8STzq6/cBR+zincoHTpen3b61fHX+JBYbogYrcqAbSDUdmyyOy+atTJR5HDhSS7lWA5YuIzuRfzIl0qiwE5wA6WPwssTCOXjHS6WzKxcKqb2UiZbmbGXAKaqu0bKjoZHCzri6C/4hS1ZbFcRNE+wc5fuEgMORg/dlMdejRcKSV4w2W3iMIm1UzRbTkWHdfYatlhncgqx6XiagJ5gzizB/MXX5II0i8/vXjxjzhCidK5g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=Z1CB5IdWjzvBOUlE+iPQ9fW7uvQXz7VqFlbF5M+sM2w=; b=XnSug3VsCmjKFOgIKbiQ2ir3M9SkxRQUHYB/eAPA1vJMTD1ZHlHgbSjVyYlf1FHULqDCJjSxgBIjzneJsM8cjAJHzhXV175hRQKv+rA8vv3XD36QKZz/+PaXtaJMJjgh6ui7jtA18uxrKjEkqrj+Xhdewy5J8U2xRDzl+/Qsmdk0iDadRGL9+4dYMR3yCCk/Abmjvm350YzSn8LoAxHt1frNI/MH8PsQgPpXp7YD0z9SH7BIRSTEZxVpBKZTNhGufufSXjyddMHPqxrY9gj6PLt90O0uEJ8hB4/I66HmvVyexDXyy8Qxf1spzFgfg31UGYnqYVthwN5U8u/w5dAaXA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=oss.nxp.com; dmarc=pass action=none header.from=oss.nxp.com; dkim=pass header.d=oss.nxp.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=NXP1.onmicrosoft.com; s=selector1-NXP1-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=Z1CB5IdWjzvBOUlE+iPQ9fW7uvQXz7VqFlbF5M+sM2w=; b=t1JXUIC5gau1l9siwbUqFMn6WPED9qtOXXEXG4Nv2Of1vJB4g4MuwdNekMGzhzUDlyHly14ywX68X5ALurkGl5EHbUv8JwchL5ltLsIpvvoS2r6UENTjMDuJuJovrBjuwgpu2+UeoqDBAR/aIxke+P7V4xhxDuxmtdLN6d3X8cEDS0Kzr6/j2y8LWbk4kjptpscz0SedO4jh0P0di0yJ5aFgbj+NxiHgWtF7uv4rEe8Z/zlJt3HW5w4twnW3Ar4iGGif1nqplWhZEcVcI0oOHwyMw1/JDXM8scEdGeTlaMYiC9EJJd9sp2NZmn4NGeQXeecuepeytMtZdqFA5+iJuw== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=oss.nxp.com; Received: from GV2PR04MB11799.eurprd04.prod.outlook.com (2603:10a6:150:2cf::9) by PAXPR04MB8815.eurprd04.prod.outlook.com (2603:10a6:102:20e::23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.181.14; Wed, 8 Jul 2026 21:03:33 +0000 Received: from GV2PR04MB11799.eurprd04.prod.outlook.com ([fe80::2146:83a2:5329:b7c]) by GV2PR04MB11799.eurprd04.prod.outlook.com ([fe80::2146:83a2:5329:b7c%6]) with mapi id 15.21.0159.007; Wed, 8 Jul 2026 21:03:32 +0000 Date: Wed, 8 Jul 2026 16:03:22 -0500 From: Frank Li To: Hongling Zeng Cc: vkoul@kernel.org, Frank.Li@kernel.org, wens@kernel.org, jernej.skrabec@gmail.com, samuel@sholland.org, mripard@kernel.org, arnd@arndb.de, dmaengine@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org, zhongling0719@126.com Subject: Re: [PATCH v4] dmaengine: sun6i-dma: Fix use-after-free in error handling paths Message-ID: References: <20260708032518.50886-1-zenghongling@kylinos.cn> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260708032518.50886-1-zenghongling@kylinos.cn> X-ClientProxiedBy: SA1P222CA0065.NAMP222.PROD.OUTLOOK.COM (2603:10b6:806:2c1::16) To GV2PR04MB11799.eurprd04.prod.outlook.com (2603:10a6:150:2cf::9) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: GV2PR04MB11799:EE_|PAXPR04MB8815:EE_ X-MS-Office365-Filtering-Correlation-Id: caf81cef-880f-47d0-5046-08dedd345e71 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|23010399003|376014|7416014|19092799006|56012099006|11063799006|22082099003|18002099003|6133799003; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:GV2PR04MB11799.eurprd04.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(1800799024)(23010399003)(376014)(7416014)(19092799006)(56012099006)(11063799006)(22082099003)(18002099003)(6133799003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?ZV1zN0hLFbcwhqpHMJW3zF1d88gFIY1up0TEAc4myTPz/fW60RhcxFph56aV?= =?us-ascii?Q?Kej80P+Nhyx49Qhf0aiIdkBItYswMXsf6L8xek6s/B6yGTOTYdyDFwt9NAH9?= =?us-ascii?Q?95r7Rd+t8jTIbND+WbP+Lvpc7NQLr4MPGF4l69g5mV7/nxWt/ePIJ0pdVnOF?= =?us-ascii?Q?hSpNKsrm6BQRO0khE/pFYbhTmfATSw7C8lGWqvQsZHFhKmqBsjG511+8TY3O?= =?us-ascii?Q?QASEWbYCzr/5QUt4/jLMFeC6kNQRDe6k4M2oElXb1JxrFol81Gw1D2EGoeVn?= =?us-ascii?Q?lgMwWj0AcnkBjllLVD9WtNTpmpZ1M13bS7OCzzpD6aAI1Y+4eYDU7RHCza3j?= =?us-ascii?Q?7z/av5aRjFytkSPdAg39GBIkOzaMtbxkVs8y4UAGwOspIldhJ+8i0F//mH0c?= =?us-ascii?Q?hoNxHCwsxyyv7U8kQbWmeVztuONMtAX/Ka6v9i+uBPYSk/6eSznlan1zeYVA?= =?us-ascii?Q?VpGQN6sE5ZfVr72LelDqcCuX6rnNe+s/gjKiY2g4vRhI6P/xSXf2bwEqJZ6U?= =?us-ascii?Q?eLiwic9e+1ZSlFZds0HlXgMdLZbzpWR5anagZxmVKGfMRrgiOGugMleVgVZq?= =?us-ascii?Q?AxaZGOHXGz14umMfio8GTKUZrqwKI9VuP5JR3dGT554gz6+40gWWVnWOtVmg?= =?us-ascii?Q?nyp7pc7ZHhNVvzU5Aswdv8gb8hmjzn12gWTCNGgWFWeISoNXDmkiZBFVIdoZ?= =?us-ascii?Q?8U76GxlBf5NZqyOG6Zwnm+7ogrl7JjFyQKrA7w+RtUfvHjVCo6b0lP/IPK9b?= =?us-ascii?Q?DZ0oNzxurcz7bPyIRfuuUMkY04tG3WJMCcHRhONqCSmPH49ApS07YwhGATzw?= =?us-ascii?Q?DT5IOiMWEcVWsQw8FGF520sj70L2R+9VjiVm4V6uDVKlEC7CzBC2BMj+AEFY?= =?us-ascii?Q?PWqu77biwkMJFSxgfEUWUgWPZkglqweeD23UVgPdVegHKO0dtXpW6HHVTyi9?= =?us-ascii?Q?M2cjul0+9RhQ/w4aLgSPaxaSy5OyXf2hkO6H7E3thHFGZBQRHe0PCQ6S9cD4?= =?us-ascii?Q?THUpB1nkrPZQPa6fIZT+B9xGYBKRYj4V6sjcD8ivRpefmVzYjW79CjsMNECa?= =?us-ascii?Q?x1MPT1RBMvovPtF9vu0hsMzu6IghkDIKiBGBXIKTwlaKJGl6pA4W3mBivvIQ?= =?us-ascii?Q?87bzbX9ELHtbvR2/YkDLe1rrzp5Ias+sz1zOkxFwCR7hLK71h3+MJhsc+tNX?= =?us-ascii?Q?gwT5wuZGocUUiA8CyJP8QsUwDiVYOJereX/5F6tkCgzMyMqkU86b0BxnK119?= =?us-ascii?Q?FjdsHvUApmDNdtg/keR518JECZ3bi1zyVz+grK85UbyUqbUaMlPJyCqSHGWW?= =?us-ascii?Q?5r81IVKrr9RymNOCHd6ddmahqzoaqJd/0YDuK1E+P88PvpYJz8xB4Fx25mpm?= =?us-ascii?Q?CFyLeZkmL7L7MjEmdj1Bu3ZlGMa+2N9S3O+tLOUhR8N0hqdUdB0vsIW3628f?= =?us-ascii?Q?M9FJLFbRvXnO8+yv9qL6ZcvOB6JpA4xEyA5O63O7R0fozRjXspi0imYkmBNK?= =?us-ascii?Q?7bDnjDD4cTSyTnulKa3Ijr2Fwiy1K2FImyJovS31rW69eVR02rNtTEAWJJ1H?= =?us-ascii?Q?XUGk6Ww3KSocnKAuReHlPaQJuOmM+UpyR3OUxre0GYeUcYICP4kXdbtb7+VJ?= =?us-ascii?Q?OtOnoWa7AYFFx6I39d1V2N6gFOukdp+M0yQFgYrjhmzXAt254fYKISDcmwmG?= =?us-ascii?Q?Xv7RP2iSkkgR8C8GaN65hPvGPUqk4ZOV5u3zJIQHygKoDZv8f3j+1J9uIxiB?= =?us-ascii?Q?edgd5B3Uz7AYLGik/RFCv9gTwl2AGyqizHAFpSP19nVCh0PT/1Ai?= X-OriginatorOrg: oss.nxp.com X-MS-Exchange-CrossTenant-Network-Message-Id: caf81cef-880f-47d0-5046-08dedd345e71 X-MS-Exchange-CrossTenant-AuthSource: GV2PR04MB11799.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Jul 2026 21:03:32.9038 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: Ji25BfFDCJYq1pkLcyBvrrMkH/h719gUmKBKud0ug4SxbWH1JPlNJUgxLiA3lzc2/T00LrOaAnycL/OE0Baw7NaHn7WUkeyeOi9gc9J/tRxbBMBeKQBSKaanoFm6F9C1 X-MS-Exchange-Transport-CrossTenantHeadersStamped: PAXPR04MB8815 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260708_140337_897923_221E486C X-CRM114-Status: GOOD ( 23.72 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Jul 08, 2026 at 11:25:18AM +0800, Hongling Zeng wrote: > In error handling paths, the for loop frees v_lli in the loop body, > then accesses v_lli->v_lli_next and v_lli->p_lli_next in the > increment expression, which is use-after-free. > > Fix by saving both the next virtual and physical pointers before > freeing the current node. > Is this statement out of date? You call sun6i_dma_free_desc_virt() where saving "both the next virtual and physical pointers..."? Frank > Fixes: 555859308723 ("dmaengine: Add driver for Allwinner sun6i DMA") > Signed-off-by: Hongling Zeng > Suggested-by: Jernej Skrabec > Reviewed-by: Jernej Skrabec > > --- > Changes in v2: > -Refactored the fix to avoid code duplication by creating a helper function > sun6i_dma_free_lli_list() that handles LLI list cleanup > -Add Suggested-by: Jernej Skrabec > > --- > Change in v3: > -Further refactoring to move txd handling into the helper function > as suggested by Jernej > --- > Change in v4: > -Add reviewed-by > --- > drivers/dma/sun6i-dma.c | 31 ++++++++++++++++--------------- > 1 file changed, 16 insertions(+), 15 deletions(-) > > diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c > index fcc88a74d821..e161fc298b86 100644 > --- a/drivers/dma/sun6i-dma.c > +++ b/drivers/dma/sun6i-dma.c > @@ -406,16 +406,12 @@ static inline void sun6i_dma_dump_lli(struct sun6i_vchan *vchan, > v_lli->len, v_lli->para, v_lli->p_lli_next); > } > > -static void sun6i_dma_free_desc(struct virt_dma_desc *vd) > +static void sun6i_dma_free_desc(struct sun6i_dma_dev *sdev, > + struct sun6i_desc *txd) > { > - struct sun6i_desc *txd = to_sun6i_desc(&vd->tx); > - struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(vd->tx.chan->device); > struct sun6i_dma_lli *v_lli, *v_next; > dma_addr_t p_lli, p_next; > > - if (unlikely(!txd)) > - return; > - > p_lli = txd->p_lli; > v_lli = txd->v_lli; > > @@ -432,6 +428,17 @@ static void sun6i_dma_free_desc(struct virt_dma_desc *vd) > kfree(txd); > } > > +static void sun6i_dma_free_desc_virt(struct virt_dma_desc *vd) > +{ > + struct sun6i_desc *txd = to_sun6i_desc(&vd->tx); > + struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(vd->tx.chan->device); > + > + if (unlikely(!txd)) > + return; > + > + sun6i_dma_free_desc(sdev, txd); > +} > + > static int sun6i_dma_start_desc(struct sun6i_vchan *vchan) > { > struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(vchan->vc.chan.device); > @@ -788,10 +795,7 @@ static struct dma_async_tx_descriptor *sun6i_dma_prep_slave_sg( > return vchan_tx_prep(&vchan->vc, &txd->vd, flags); > > err_lli_free: > - for (p_lli = txd->p_lli, v_lli = txd->v_lli; v_lli; > - p_lli = v_lli->p_lli_next, v_lli = v_lli->v_lli_next) > - dma_pool_free(sdev->pool, v_lli, p_lli); > - kfree(txd); > + sun6i_dma_free_desc(sdev, txd); > return NULL; > } > > @@ -869,10 +873,7 @@ static struct dma_async_tx_descriptor *sun6i_dma_prep_dma_cyclic( > return vchan_tx_prep(&vchan->vc, &txd->vd, flags); > > err_lli_free: > - for (p_lli = txd->p_lli, v_lli = txd->v_lli; v_lli; > - p_lli = v_lli->p_lli_next, v_lli = v_lli->v_lli_next) > - dma_pool_free(sdev->pool, v_lli, p_lli); > - kfree(txd); > + sun6i_dma_free_desc(sdev, txd); > return NULL; > } > > @@ -1432,7 +1433,7 @@ static int sun6i_dma_probe(struct platform_device *pdev) > struct sun6i_vchan *vchan = &sdc->vchans[i]; > > INIT_LIST_HEAD(&vchan->node); > - vchan->vc.desc_free = sun6i_dma_free_desc; > + vchan->vc.desc_free = sun6i_dma_free_desc_virt; > vchan_init(&vchan->vc, &sdc->slave); > } > > -- > 2.25.1 >