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=1793210196; b=4Yh1kb7LVfS4vT7IKSPlmFOPyJvn2zC6JvRAWbANixs1hsvkZ0i8juPNafw63QIDwMov ZzAU2Pn4FPU9E2GuVc85FimWVK8VZUFnr3XY452RiNJrhVAMfp3G9WuGOLVhqHyfM65kf ZQv9GSkMeXEL/rQlGMIb9TlWla0bPKJSV7cDwelXXbeKCvCFjb8jbhkdYGMoaJvOUSuTV tQlO1uSNNnX+OzO4Mor3ZpzGwLINSTyA3ZJPnX0NpN/1Tqigfb95MArECdOXZWxStTgzK DE+NYsd1yaofifmlrFw1jh1lKu+lVT+R6ZxtzquKERDYOKftwlyKIRqE4YPHINFmc3Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793210196; 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=4oCURdyPXwEZSM2XMmUm8zholjp8RuE40nQA/MaKfq8=; b=CJXM6FEhhvgY9I42sqUEE7PinmzEa+1MWjwKpjbth5z1M7i4aO5TzaZCVzF5uwfywEHi d2rrAeYwahpqvkX6FGBci/UiwC/SxMx4Oqh+Pu9WwEf/Jfr+NqLzoCvnXoo0bshGKef0N DcuPWROBRhj5q0DW4U3HUiR+/7CDtU3xHDKr1JtoSF/KfJF2IFZTJRc629D3gK3LtMM/D b7smO2MeUJ09C/NcEjJ3Zu/n70yrMXeTsJuQ/WvOJxhPXVEOIDcPsl112YhmYMbmqyOHJ yFUPPUy6EEdhzxFpJWVbzf1YVe6X0cUa37M9UY+DV1oXQ0d65a6WO1f/8Ig2xOuFVVQ== 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=UkjXBWTm; 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 D3A11606A32E; Wed, 28 Oct 2026 17:56:35 +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=UkjXBWTm Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2EF011F01825; Wed, 28 Oct 2026 17:56:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793210195; bh=4oCURdyPXwEZSM2XMmUm8zholjp8RuE40nQA/MaKfq8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=UkjXBWTm9doG7VH5/Fe9yq+LH5BLdZYgORf3bXV85P6F6NLslsd0KYASV4ncYFaGr ad7iyh+LZrTNs/Gei5xz1SHhCJLU50Lli5OUVEgL5i503LiZVIyfK31ii55EjY+ZuY eHW/q79jhV/ajPnGfjTw2uf1tARya+x09fK6aVAg= 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 6.6 111/168] drm/i915/dmc: Harden DMC firmware payload parsing Date: Wed, 28 Oct 2026 18:00:47 +0100 Message-ID: <20261028165945.714644301@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028165943.089486480@linuxfoundation.org> References: <20261028165943.089486480@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 6.6-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 8751973b5730f..8d42ae60d8625 100644 --- a/drivers/gpu/drm/i915/display/intel_dmc.c +++ b/drivers/gpu/drm/i915/display/intel_dmc.c @@ -770,7 +770,7 @@ 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; } @@ -785,13 +785,21 @@ 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; @@ -799,12 +807,15 @@ 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