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=1793211915; b=a568xvZRrVyhzTDjHXnUr6k7qe/BYR6LKkh6arq3TwpzhXRPKV98h+tK9GZZA6QltJc+ y+t3seTRfpJ03FCJEvmNqzDGigf9TpTBFDG/zirOFjRAWCgsF0iUet1tJBhVCywBUM6ZC dmrRFaE4QvHb6tz1szqS562fIeAhkuU7N5N8etgSactI0bcvAZfx7ECFUhcgC2XUDwl4U pWfivbjDAq/xdDsSk6Ds/5OBFHnZ0XxNx8GD2ixK9Vu5CAuNtQGMJFCANco/ITejcffBN 7u/FugtJekn7rgy0c+x/r+fWg9eK+oehUbZliZOX5Wwnw+dW3F6y8qEZtxN4Upye/uA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793211915; 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=yH8BOrC+kUeL2G7VmIawrWhZRYD21rv1+0q136xdxAc=; b=kIO6HGw+a0wvBNLSLRCXMKbOqNGl6tSzeh+7xDkTpXBUNENY7GPIqJmp5qBmehmMxmao M5mz8aFlQQieP9Ry53GmfutWzEyhnXeOmlBFI/K3yZQC8mjSrGgxX4u2kuq9f9qk6kxMQ fHn/GVPcPY6Y3nCwGg+IXCqxcBYgt22ePc99Y5IzbtK07HzVKRm3aTGU5oGZibmv0eDG5 yXvMnyoWO0aF9paUlPD7nMrV7zybT43PmnDmHAu+QjUP+IlQc2kUy6bVdFxnu8J/Z7B2j 6sUSiDCaDq6i7beOd0gB2hgjZg9KcbAixobaKpE5pjNbhDB3ID6tODuEZtZUtv1JtRQ== 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=ixgc89Y0; 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 18512606A31A; Wed, 28 Oct 2026 18:25:15 +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=ixgc89Y0 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6917F1F01825; Wed, 28 Oct 2026 18:25:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793211914; bh=yH8BOrC+kUeL2G7VmIawrWhZRYD21rv1+0q136xdxAc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ixgc89Y0lR/vO6pkBFnFMT7ne4wu9QhI3iGA0E6IqKwGN2zuuixafe3Wtqi4U4zu9 /jXvY9d/V6XTDTS9Qe2PHsrRGtG6As6L4NNnKVa+r4uSrYj7FtWppbVRhNvlg9k+mm wbJ6vWuOY244pty0WVK6BUtvRa5W6te+IVYzgT30= 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 5.15 544/571] drm/i915/dmc: Harden DMC firmware payload parsing Date: Wed, 28 Oct 2026 18:01:31 +0100 Message-ID: <20261028170020.945077062@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170008.009143722@linuxfoundation.org> References: <20261028170008.009143722@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 5.15-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 drm_err() calls to use &i915->drm instead of display->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 0e04d4dd1c132..a0d6eb90d55a3 100644 --- a/drivers/gpu/drm/i915/display/intel_dmc.c +++ b/drivers/gpu/drm/i915/display/intel_dmc.c @@ -477,7 +477,7 @@ 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; } @@ -492,13 +492,21 @@ static u32 parse_dmc_fw_header(struct intel_dmc *dmc, dmc_info->mmioaddr[i] = _MMIO(mmioaddr[i]); dmc_info->mmiodata[i] = mmiodata[i]; } - 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; @@ -506,12 +514,15 @@ 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