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=1793207818; b=oIJpTn/TMX4iL3FBA/7qNTN/wFBPumDDNnk8xxWEEBMl4vZNxVs5VrsWI0HSQcU/m9Ro yTKyH4a/nkAxg2hgzkoMcIozOCNXmkYk6JIy5w9vnG9eiDROHfeXZrWhOpXpw1Lqp5P/O olCN7LwrV3sUGT04fn+McFqSYc9J8NI833OJH8mVIVMqH1hmveKm3Jw0O6cIJq+/INkY2 Igizmjn4h89EhiKpX30axk1k9K1Tf9LPrsgDohQN+U6H9VBBWd2W1mKRIkRIzUoLoMIg/ g8xmCzrZufqgaP9RJESBq3bx0smiUux+ThGOQGH6TEwB4+2TRDcyCMRNvI6NcZ+T1Tw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793207818; 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=eZhmea06dscMMUglcXS3CQeV6ZxGsykq5nDyPxj/d9M=; b=oxHdYb+Si5lRyVuiLRsikNmf+YwH6bGpMUf3jwbuMihFLdFRKZ1AfNeRa5j6+I2JHs1O ybSOjWXtJ7DeBnbgPUHiqlWoI60OaQLBlqEp7SgkLkLakFLsSrxja1EbgiRv1uWqj7Qfh 9TuYOXwcGEXh7fyICa23AjSl+ZCvn6yu508m/B84X3okcKKCXdAk89Rl9wq4bZUsQSD5c b6ofmuQWvnfMYBjWYMT49MCzFW8MQOByAYhzTIAmiRs7nbzsxn643vIwu8ndwCO8j7LbF NekTnQXK7TjnsM2cvMnL3jRZ4o1DJ+Y1Ou/Aracszrzu3UIyCoUxVgqYtzZUAWcijaA== 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="A4gXQf/r"; 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 59D88606A31C; Wed, 28 Oct 2026 17:16:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=A4gXQf/r Received: by smtp.kernel.org (Postfix) with ESMTPSA id A52EF1F031E1; Wed, 28 Oct 2026 17:16:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793207818; bh=eZhmea06dscMMUglcXS3CQeV6ZxGsykq5nDyPxj/d9M=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=A4gXQf/rLTcJsqzHHq9oYQEoWhQPYnKhQcsDn8tfYU6ejJ28YPAji3Z0nq0CJHujo nPJf7YC+z+cRtfjK9iIzhDQGPp24mrrVP3h4QAhsY6FkTjw8MsftYkeAChnikauat4 vb/TwKzpfdAHaqaMbciOjLaFajJ0A9eKrtq5E4SU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dibin Moolakadan Subrahmanian , Mitul Golani , Ankit Nautiyal , Joonas Lahtinen , Sasha Levin Subject: [PATCH 6.12 150/247] drm/i915/dmc: Harden DMC firmware payload parsing Date: Wed, 28 Oct 2026 17:59:13 +0100 Message-ID: <20261028165950.964237030@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028165947.349197979@linuxfoundation.org> References: <20261028165947.349197979@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dibin Moolakadan Subrahmanian [ Upstream commit 8bb1858db453cd4250e3b633f5d2d09206024ca6 ] Validate the conversion of the DMC firmware size from dwords to bytes using check_mul_overflow() before calculating the firmware payload size. Reject zero-length payloads and zero MMIO counts in the DMC firmware header so malformed firmware is caught early. Also set dmc_fw_size only after the payload allocation succeeds. Fixes: eb805623d8b1 ("drm/i915/skl: Add support to load SKL CSR firmware.") Cc: stable@vger.kernel.org Assisted-by: Claude-Code:Sonnet-5 Signed-off-by: Dibin Moolakadan Subrahmanian Reviewed-by: Mitul Golani Signed-off-by: Ankit Nautiyal Link: https://patch.msgid.link/20260922133535.3180973-5-dibin.moolakadan.subrahmanian@intel.com (cherry picked from commit efde6601a1f1daedfe3dcc2816c934ddb44e3eef) Signed-off-by: Joonas Lahtinen [ sashal: Changed logging arguments from `display->drm` to `&i915->drm`. ] Signed-off-by: Sasha Levin --- drivers/gpu/drm/i915/display/intel_dmc.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_dmc.c b/drivers/gpu/drm/i915/display/intel_dmc.c index 7c756d5ba2a22..641dabf275e73 100644 --- a/drivers/gpu/drm/i915/display/intel_dmc.c +++ b/drivers/gpu/drm/i915/display/intel_dmc.c @@ -796,7 +796,7 @@ static u32 parse_dmc_fw_header(struct intel_dmc *dmc, } /* Cache the dmc header info. */ - if (mmio_count > mmio_count_max) { + if (!mmio_count || mmio_count > mmio_count_max) { drm_err(&i915->drm, "DMC firmware has wrong mmio count %u\n", mmio_count); return 0; } @@ -819,13 +819,21 @@ static u32 parse_dmc_fw_header(struct intel_dmc *dmc, disable_dmc_evt(i915, dmc_id, dmc_info->mmioaddr[i], dmc_info->mmiodata[i]) ? " (disabling)" : ""); } - dmc_info->mmio_count = mmio_count; - dmc_info->start_mmioaddr = start_mmioaddr; rem_size -= header_len_bytes; /* fw_size is in dwords, so multiplied by 4 to convert into bytes. */ - payload_size = dmc_header->fw_size * 4; + if (check_mul_overflow(dmc_header->fw_size, 4u, &payload_size)) { + drm_err(&i915->drm, "DMC fw_size too large (%u dwords)\n", + dmc_header->fw_size); + return 0; + } + + if (!payload_size) { + drm_err(&i915->drm, "DMC firmware has empty payload\n"); + return 0; + } + if (rem_size < payload_size) goto error_truncated; @@ -833,12 +841,15 @@ static u32 parse_dmc_fw_header(struct intel_dmc *dmc, drm_err(&i915->drm, "DMC FW too big (%u bytes)\n", payload_size); return 0; } - dmc_info->dmc_fw_size = dmc_header->fw_size; dmc_info->payload = kmalloc(payload_size, GFP_KERNEL); if (!dmc_info->payload) return 0; + dmc_info->mmio_count = mmio_count; + dmc_info->start_mmioaddr = start_mmioaddr; + dmc_info->dmc_fw_size = dmc_header->fw_size; + payload = (u8 *)(dmc_header) + header_len_bytes; memcpy(dmc_info->payload, payload, payload_size); -- 2.53.0