From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EA97B4F405E; Wed, 30 Sep 2026 18:14:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790792088; cv=none; b=W8W2s5tDYtsEw4rdEAoudVIaZ3kF66+9WdzR4WIWxhEWMF5o8zmcNj/qLQ3Bp98upeQAcNul8fxxPtxxYE1VTVS3j7YtUXZAY2fgvWzlV/1mZ/0kN1q8GUdMDz0wSL4pazImTtn5pp3f42hRmOLHl9Pz1Bsrx6Booo1ZrEiTEs0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790792088; c=relaxed/simple; bh=GwCQn6inStlurXyIEgjhgDmiCcKw7ba8tmtHvHVNtPE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Kgz9y4I8QorVgoVyLDoBGS0jw+WbxxmyTuwwHHfTV8KSwQC7cTbaziZF0uRJdmFZsGonbuVoq7D09qEx40l4DsKQ/VYRoVTwGO2vTVEIf/ByDD+GICaRWZlw6incmsvJ81RyFrt+3J5zWKM+bh9ZcbpMwA4YWdriM4hBjExVQcw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=2P5LIIQJ; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="2P5LIIQJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4922C1F000FF; Wed, 30 Sep 2026 18:14:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790792086; bh=QOOJyPxsc5t3lEwt3n0sz/7NBePio/VjupF1AN/5pOk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=2P5LIIQJKRP4yz5Zme+2YGHvhteTC+9lOiEdZjqpN7hnYpkCPyMhfld8rapDWby+J 9QAnPGczvHrd3bBzJtULhv62OuaXWfROVhhSrLd2yms7MNwYG5fMW8CFObMXsNnkwg l8rYEOXdPOYsueHCeBfRUndcPVALCtH+6eJxOVvQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Christian Lugnberg , Frank Li , Vinod Koul Subject: [PATCH 5.15 531/752] dmaengine: sun6i: fix undefined behaviour in sun6i_dma_tx_status Date: Wed, 30 Sep 2026 17:26:41 +0200 Message-ID: <20260930152409.742893229@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152358.131179731@linuxfoundation.org> References: <20260930152358.131179731@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Christian Lugnberg commit 9096bdc8d930147f7c39a493a859acbd3a8485d8 upstream. sun6i_dma_tx_status() calls vchan_find_desc() to look up the virtual descriptor for a given cookie, before checking whether the pointer vd is NULL: vd = vchan_find_desc(&vchan->vc, cookie); txd = to_sun6i_desc(&vd->tx); /* vd may be NULL here */ if (vd) { for (lli = txd->v_lli; ...) vchan_find_desc() returns NULL when the descriptor has already been completed or is in-flight on a physical channel and no longer present in the virtual channel's descriptor list. When vd is NULL, to_sun6i_desc() is called unconditionally on &vd->tx before the NULL check, which is undefined behaviour. Move the call inside the if (vd) guard to ensure it is only reached with a valid pointer. vd = vchan_find_desc(&vchan->vc, cookie); if (vd) { struct sun6i_desc *txd = to_sun6i_desc(&vd->tx); for (lli = txd->v_lli; ...) Fixes: 555859308723 ("dmaengine: sun6i: Add driver for the Allwinner A31 DMA controller") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-sonnet-4-6 Signed-off-by: Christian Lugnberg Reviewed-by: Frank Li Link: https://patch.msgid.link/20260817135723.12807-3-christian.lugnberg@soundtrack.io Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman --- drivers/dma/sun6i-dma.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/drivers/dma/sun6i-dma.c +++ b/drivers/dma/sun6i-dma.c @@ -931,7 +931,6 @@ static enum dma_status sun6i_dma_tx_stat struct sun6i_pchan *pchan = vchan->phy; struct sun6i_dma_lli *lli; struct virt_dma_desc *vd; - struct sun6i_desc *txd; enum dma_status ret; unsigned long flags; size_t bytes = 0; @@ -943,9 +942,9 @@ static enum dma_status sun6i_dma_tx_stat spin_lock_irqsave(&vchan->vc.lock, flags); vd = vchan_find_desc(&vchan->vc, cookie); - txd = to_sun6i_desc(&vd->tx); if (vd) { + struct sun6i_desc *txd = to_sun6i_desc(&vd->tx); for (lli = txd->v_lli; lli != NULL; lli = lli->v_lli_next) bytes += lli->len; } else if (!pchan || !pchan->desc) {