From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f53.google.com (mail-wm1-f53.google.com [209.85.128.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DBB4843E490 for ; Tue, 16 Jun 2026 16:54:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781628881; cv=none; b=acJSntnuNsAhtq7RJyf7Xa3rg/TJBuF01jI58hb4xzvQL5xX7zTa/8icavzhsKKODpFRs/nStCFQe154EqeQQSHHT1Lx8tshsmexBU0mUU8gcbpMoBqe0XGz5E9yX97jkdXCzqlQyJXmK1EhxvqnrpSIZlTL3gV0Hfu+zEhHKCs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781628881; c=relaxed/simple; bh=Q3ogCEiEplFsajmHh+DrlKd0CFRslk5VBsvGzlR4oX8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=nRJStPOecD/6Aw3Ed8keDb4EbvNkRZs/qfuYA1iDrwmXGgW50qFHT52E/v+vNG0nCR9O+/LKE2tZxrgDEVvcF22DKpLoOtT653orHRrSzuS7kxDPAxHpG87vanzmUFkJYkQA9BrbddfEismlbjV0nLuD/H+8+jMOHXbg3lP6bb0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=OSxg1Bw1; arc=none smtp.client-ip=209.85.128.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="OSxg1Bw1" Received: by mail-wm1-f53.google.com with SMTP id 5b1f17b1804b1-490afc47455so21987375e9.2 for ; Tue, 16 Jun 2026 09:54:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1781628878; x=1782233678; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=exFxm0hh9AfcFczlY3WuFGnTo6SOwxmm6hFx+zY5Z3Q=; b=OSxg1Bw10IsREGiBf1ZE0l799sFTQuRvmqfI8ENfeDPi5YzRfMBHDnNlCHGM9Z8SsG hCccjlOTYeeL4NTm/zxp+Uv+sitJjxnJUs4lbG4H1dPnva0ihpOyz5tol+gg4gnWak2x G9Zh099QAKbjSJXn5P3cwiAXgLDPFcEVNsnQLpQYmhVnOVM7Zhay9C34k+UZw0KCkBbs eqJf3XBDcKq5UdT44+fgMWtZHrekbSnKrqsXG9wqdQ7szglOB8a+pqzND2L4YGJgh9Hq zLES3FsHdITSkYpenK1besLahqCRiagFs7plKX2NfFID2V4YbcS6lLuPi4AEsJkyZHlr 3dvQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781628878; x=1782233678; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=exFxm0hh9AfcFczlY3WuFGnTo6SOwxmm6hFx+zY5Z3Q=; b=EiiQzQX8TQ00VF22fZ1NqBNqFQqAS2wdT+5cXTgx2d3oElstlLq2HNZ1o3jDuorSgL ShhW/qCGNryFRPQSrPh7kczq7ysSx4CZGjZEHKEPQryhVZGd3E/zbCigGwAoLVpS2qJq JXs1vQ3jJu09YDGi5vWEb6rfUWQ0o/jGW58ntUU4oqMiCDOVh+HHo7i3HQ1RNIFpTkJT +0APp4Qyw2VcCXN4BerHl6ypnInJt4O2W80OFnYkK5jeDoCtxAYoYBNEHXbNr/OKP0iH in6R3Kjz7Bnkc9IJbN+gnQVQEFkycCmoDzDKCaQyMilIIN5O3hc52S33nQ4ArjRHja/6 zShA== X-Forwarded-Encrypted: i=1; AFNElJ9d0XTrX+YhXLIN8GfYAg4Hd5Z/xWaHi79sEidSM+33EPjn4QgWMm/7QOLD1Bq/t8ZJF+DVV0N76hjnfys=@vger.kernel.org X-Gm-Message-State: AOJu0YwEhLh1vZok2xP6lFi2GDkp3qsoFZwSfvAH5+fGwvwfAFAIbu/+ 8QUQz4jwUSc09pnxi/paq0Z+L3xR+sBPbMNgy1q6hshBvw8OhLgWuuyk X-Gm-Gg: Acq92OFNpBK3wVBq12hT+TidQ2UL2eGMoVzi7XoFToRHz071Eg0zdo7olzZHk34crgq PF3S+jQzWO5w5b1lsAH5Npf3sDWiDop2VkP5PqEAcD2XvCu17EbTBR6yHSxrKqMwGJQELCva4Un 0pW/hraxXLhYUVCucUnS6Uw8K0q4DBwnvz1smTgP+0WpN6GJBZvkkAuRXVMX5rwrTmbSPaMz6U0 ZRfqhOYnuxAUqfW9/MSZu+5JfQy3bhaROQ4XGq0+Q+y2VpaZ2HsKsZ5ESO1/vSHlrcLOW5OkV07 I9v9TPysag08OAUsRDxrpqqjDd4aOzjbcVbpPnmA8aK6cVuOHeQ2KAQjwQduDJdD3WXbD/Bb3UH /4uYhm60dzeeIU1pEeeOYCsefRv3e9Zg+rMTqTzwzotHeZecPRtA5yJ9D0Il8m83lQCXPG1eN3j vV5P3jn+MdjPsfrpuOq7GDd7IADZhiyfjOXeuwA7klShYm8smD9nmTO8BOncVKJNDjxepyII5cz oDSVe+TQNbu4xp0VAGfMaDSdnbr+azsKhYRBgkJbcoKbfM= X-Received: by 2002:a05:600c:a111:b0:492:301e:3270 with SMTP id 5b1f17b1804b1-492333af267mr5549255e9.13.1781628878052; Tue, 16 Jun 2026 09:54:38 -0700 (PDT) Received: from jernej-laptop.localnet (APN-122-99-120-gprs.simobil.net. [46.122.99.120]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-4620b1083e3sm1842555f8f.20.2026.06.16.09.54.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 Jun 2026 09:54:37 -0700 (PDT) From: Jernej =?UTF-8?B?xaBrcmFiZWM=?= To: vkoul@kernel.org, Frank.Li@kernel.org, wens@kernel.org, samuel@sholland.org, mripard@kernel.org, arnd@arndb.de, Hongling Zeng Cc: dmaengine@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org, zhongling0719@126.com, Hongling Zeng Subject: Re: [PATCH v3] dmaengine: sun6i-dma: Fix use-after-free in error handling paths Date: Tue, 16 Jun 2026 18:54:35 +0200 Message-ID: In-Reply-To: <20260616023138.15904-1-zenghongling@kylinos.cn> References: <20260616023138.15904-1-zenghongling@kylinos.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Dne torek, 16. junij 2026 ob 04:31:38 Srednjeevropski poletni =C4=8Das je H= ongling Zeng napisal(a): > 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. >=20 > Fix by saving both the next virtual and physical pointers before > freeing the current node. >=20 > Fixes: 555859308723 ("dmaengine: Add driver for Allwinner sun6i DMA") > Signed-off-by: Hongling Zeng > Suggested-by: Jernej Skrabec >=20 > --- This looks great! Thank you for your patience. Reviewed-by: Jernej Skrabec Best regards, Jernej > Changes in v2: > -Refactored the fix to avoid code duplication by creating a helper funct= ion > sun6i_dma_free_lli_list() that handles LLI list cleanup > -Add Suggested-by: Jernej Skrabec >=20 > --- > Change in v3: > -Further refactoring to move txd handling into the helper function > as suggested by Jernej > --- > drivers/dma/sun6i-dma.c | 31 ++++++++++++++++--------------- > 1 file changed, 16 insertions(+), 15 deletions(-) >=20 > diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c > index a9a254dbf8cb..7a79f346250a 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); > } > =20 > -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 =3D to_sun6i_desc(&vd->tx); > - struct sun6i_dma_dev *sdev =3D to_sun6i_dma_dev(vd->tx.chan->device); > struct sun6i_dma_lli *v_lli, *v_next; > dma_addr_t p_lli, p_next; > =20 > - if (unlikely(!txd)) > - return; > - > p_lli =3D txd->p_lli; > v_lli =3D txd->v_lli; > =20 > @@ -432,6 +428,17 @@ static void sun6i_dma_free_desc(struct virt_dma_desc= *vd) > kfree(txd); > } > =20 > +static void sun6i_dma_free_desc_virt(struct virt_dma_desc *vd) > +{ > + struct sun6i_desc *txd =3D to_sun6i_desc(&vd->tx); > + struct sun6i_dma_dev *sdev =3D 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 =3D to_sun6i_dma_dev(vchan->vc.chan.device); > @@ -788,10 +795,7 @@ static struct dma_async_tx_descriptor *sun6i_dma_pre= p_slave_sg( > return vchan_tx_prep(&vchan->vc, &txd->vd, flags); > =20 > err_lli_free: > - for (p_lli =3D txd->p_lli, v_lli =3D txd->v_lli; v_lli; > - p_lli =3D v_lli->p_lli_next, v_lli =3D v_lli->v_lli_next) > - dma_pool_free(sdev->pool, v_lli, p_lli); > - kfree(txd); > + sun6i_dma_free_desc(sdev, txd); > return NULL; > } > =20 > @@ -869,10 +873,7 @@ static struct dma_async_tx_descriptor *sun6i_dma_pre= p_dma_cyclic( > return vchan_tx_prep(&vchan->vc, &txd->vd, flags); > =20 > err_lli_free: > - for (p_lli =3D txd->p_lli, v_lli =3D txd->v_lli; v_lli; > - p_lli =3D v_lli->p_lli_next, v_lli =3D v_lli->v_lli_next) > - dma_pool_free(sdev->pool, v_lli, p_lli); > - kfree(txd); > + sun6i_dma_free_desc(sdev, txd); > return NULL; > } > =20 > @@ -1431,7 +1432,7 @@ static int sun6i_dma_probe(struct platform_device *= pdev) > struct sun6i_vchan *vchan =3D &sdc->vchans[i]; > =20 > INIT_LIST_HEAD(&vchan->node); > - vchan->vc.desc_free =3D sun6i_dma_free_desc; > + vchan->vc.desc_free =3D sun6i_dma_free_desc_virt; > vchan_init(&vchan->vc, &sdc->slave); > } > =20 >=20