From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794062735; b=tHZVIS3zAQsmw4lb5CaQrsNyEer5Otrf3YXAaCIC99cEK1J3SBp5wlUBtopQNy97ubX4 Uz0nmL1H4/+QCC1QAf2IxjcwqJVAhYWZTnlnKxpyBbJZYr57PVmGtSItrPYzjwmj+0smo d1cvwlj0pNhR5CFXbrnyeLC9gyb4QTy+PeOK3oNcN4+CjLpUu/o75EXwTOjH9UmiRfSML 8pNyk0m5gDsbkEoeIaE6u2jNNbnIZZogjXNd8CZWZd2W3MljtnPCsuQTZ7jo092fTyWI+ xo9TKhlwfTnjlkBYuoQ/CsJW0jojVHYM+6TzP2fFjd6fBWrgVI0EozFYYeuUsa5UaEw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794062735; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=SBFV1CO1Mo9GPp7LGHt66nHDXPrFgvAX3RUfQ8f9i3Y=; b=jJaikl0mckEt4Jh2wrVGUnJKtKsFNzPJX+Gn1xKE0SNamqudVe8tG0VwCwa9DJvnBhqA CzrRbcag6JUk2y6TsJMlktF8TxSoA3UTEI7SdK3osAYTIzdDgsxMeqmUderlxHXH3D+/y fyJqyoqHXBuWYy0UReAYGuzQD+BzromomI/loRr+mi9huupvQq/DvX0Ygo4lW1dIm4AOv pENC1fjxu4l4k/17hwetSW9O2VDQpaJgaVJrY+QBzAD9u0s4GNaQ0HPiz8iRGDV78QLNj 5AdAQdAb1fWHJYeCWSXCJYh16QOXDO+VGOtoocOKqRDGUI/jcWW44cyaO+P8pjlSTDw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=0AR2g4EX; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 81215606A32D; Sat, 7 Nov 2026 14:45:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=0AR2g4EX Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2FA2A1F0089F; Sat, 7 Nov 2026 14:45:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794062735; bh=SBFV1CO1Mo9GPp7LGHt66nHDXPrFgvAX3RUfQ8f9i3Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=0AR2g4EXvZG0WPEo2gPvfqIMMERPe5Zf8BOClMyVqMq12HUUj9fRSNspo1PocUITB M5ksJcsbU5+4dQ1XIaVRbtn+5wQo3LC1dL2tfIe/Hrzam+GlUR0BBF0U2n4P/Pf3CJ TrwDt7t9GvLnZmoBsnyh1EwLG8BDJb/9o/nYx3KA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Justin Chen , Danesh Petigara , Florian Fainelli , Krzysztof Kozlowski , Sasha Levin Subject: [PATCH 6.18 053/869] memory: brcmstb_dpfe: Fix out-of-bounds access due to DCPU offset Date: Sat, 7 Nov 2026 08:45:35 -0500 Message-ID: <20261107134853.886069954@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134852.069646174@linuxfoundation.org> References: <20261107134852.069646174@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Justin Chen [ Upstream commit 7c0b82d087908765c6c7daeb06943e21b78d523e ] On API v1/v2 boards, the DCPU coprocessor can steer kernel readl_relaxed() and writel_relaxed() to any address within 256 MB of the ioremapped DPFE dmem or regs base. The DCPU firmware provides a 28-bit offset which the driver adds to the ioremap base without any bounds checking in get_msg_ptr(). This allows a compromised DCPU firmware to trick the host kernel into reading or writing arbitrary memory-mapped I/O registers in vmalloc space. When combined with a root-writable sysfs file like dpfe_refresh, it provides an arbitrary MMIO write primitive. Similarly, world-readable sysfs files can be used to leak other devices' register contents. Fix this by recording the resource_size() of the dmem and regs ioremaps at probe time, and rejecting any offset that, along with the largest field accessed (DRAM_VENDOR_ERROR + sizeof(u32)), exceeds the recorded mapping size. Fixes: fee5f1ef6cf7 ("memory: brcmstb: dpfe: support new way of passing data from the DCPU") Cc: stable@vger.kernel.org Signed-off-by: Justin Chen Assisted-by: Gemini:gemini-3.1-pro-preview cursor Signed-off-by: Danesh Petigara Reviewed-by: Florian Fainelli Link: https://patch.msgid.link/20260826201500.3000125-2-danesh.petigara@broadcom.com Signed-off-by: Krzysztof Kozlowski Signed-off-by: Sasha Levin --- drivers/memory/brcmstb_dpfe.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/drivers/memory/brcmstb_dpfe.c b/drivers/memory/brcmstb_dpfe.c index 08d9e05b1b338..66343205f585b 100644 --- a/drivers/memory/brcmstb_dpfe.c +++ b/drivers/memory/brcmstb_dpfe.c @@ -182,6 +182,8 @@ struct brcmstb_dpfe_priv { void __iomem *regs; void __iomem *dmem; void __iomem *imem; + resource_size_t regs_size; + resource_size_t dmem_size; struct device *dev; const struct dpfe_api *dpfe_api; struct mutex lock; @@ -401,9 +403,14 @@ static void __iomem *get_msg_ptr(struct brcmstb_dpfe_priv *priv, u32 response, */ switch (msg_type) { case 1: + if (DCPU_MSG_RAM_START + offset + DRAM_VENDOR_ERROR + + sizeof(u32) > priv->regs_size) + goto bad_offset; ptr = priv->regs + DCPU_MSG_RAM_START + offset; break; case 0: + if (offset + DRAM_VENDOR_ERROR + sizeof(u32) > priv->dmem_size) + goto bad_offset; ptr = priv->dmem + offset; break; default: @@ -415,6 +422,12 @@ static void __iomem *get_msg_ptr(struct brcmstb_dpfe_priv *priv, u32 response, } return ptr; + +bad_offset: + dev_err(priv->dev, "DCPU returned out-of-range offset %#x\n", offset); + if (buf && size) + *size = sprintf(buf, "ERROR: DCPU offset out of range\n"); + return NULL; } static void __finalize_command(struct brcmstb_dpfe_priv *priv) @@ -858,6 +871,7 @@ static int brcmstb_dpfe_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct brcmstb_dpfe_priv *priv; + struct resource *res; int ret; priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); @@ -869,17 +883,21 @@ static int brcmstb_dpfe_probe(struct platform_device *pdev) mutex_init(&priv->lock); platform_set_drvdata(pdev, priv); - priv->regs = devm_platform_ioremap_resource_byname(pdev, "dpfe-cpu"); + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dpfe-cpu"); + priv->regs = devm_ioremap_resource(dev, res); if (IS_ERR(priv->regs)) { dev_err(dev, "couldn't map DCPU registers\n"); return -ENODEV; } + priv->regs_size = resource_size(res); - priv->dmem = devm_platform_ioremap_resource_byname(pdev, "dpfe-dmem"); + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dpfe-dmem"); + priv->dmem = devm_ioremap_resource(dev, res); if (IS_ERR(priv->dmem)) { dev_err(dev, "Couldn't map DCPU data memory\n"); return -ENOENT; } + priv->dmem_size = resource_size(res); priv->imem = devm_platform_ioremap_resource_byname(pdev, "dpfe-imem"); if (IS_ERR(priv->imem)) { -- 2.53.0