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=1793209512; b=n09EhIiAzHF3jvT7E5ybxmSEla4Rxu4Eq41+dr/VtUF7wtPsX1T9u2gksa3W4tL0qNxv 6meC6XVTGylbW1W4fXgF+kz7XaEd2CQJlZmt+UCmM8mbwN3+69Zpq+oR4J5OzSnhlTqLE 3ALVc8vIfixxpjMLsKLyKOQVYOsf3KAGiq24GcEtoEe1arMsQliYMfP8n2MzraXpJRxcg /tuy9w6x7Wq+ElIbCwr5H7FY8iEJA3N1TLAumAwVCrpVaqwejalxmUDn7shv6tjDdA68J RL3dwxbAaTyBH/WPfPvitnC9u4tVe1MFrhCDqyS1B9NTwA2C1aomggi9aZbO40eG1Lw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793209512; 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=82diPvffMxISCQAdfZTXGVIu+DM+DzwPX4oRei7ecs8=; b=JAgZ8PwkQFxF6KwnzsUpIGqZ50pH2l0KMIxL0Z+9GhF7eMnaKi05Ml9gQjdbnNMVHPGl yLfg6hBy+/4c+ZSJrkqCRt/y2trPbCHFxnylxMpeTfPLMPz4NbuuG8zfTHpFpayTWGqq2 dg+N/nlJDgF5z3WSlf6rOVUHtgoVrT8a2FZjEQvS/BSXTOAsuUcsDy9kS065LP0qKva3F nqrSnZzRZZ3fGPscogSmOzRQ/zmEeg+TQNjnJfoBHoWKGXEYQZZSKqJpPxorBHjECebVJ 3Wj8RCT+w9gs1sBgrbF179qOAVY6S7WToERM2arVLA1dfKwosizOL2W4aHh2vToVrbA== 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="bTr/MRm2"; 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 DBB94606A31A; Wed, 28 Oct 2026 17:45:11 +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=bTr/MRm2 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 31DFA1F01825; Wed, 28 Oct 2026 17:45:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793209511; bh=82diPvffMxISCQAdfZTXGVIu+DM+DzwPX4oRei7ecs8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=bTr/MRm2cJfaPRONGUzHlDBMOHeXolz6JZLAY9jntXX/WgNuSXAqG1TaBRpQVHG1A IiPZAPWQwS5GH84LiHLXXG8YLalVLxJyro1QmrlZX/OMtyUlRxoQUKxw9e0KxumRQ8 kXtlduM9ctL/66kgScbH6wkWwCZxGrb1jJaZJaJU= 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 5.10 496/516] drm/i915/dmc: Harden DMC firmware payload parsing Date: Wed, 28 Oct 2026 18:00:48 +0100 Message-ID: <20261028170015.230491473@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170003.522232767@linuxfoundation.org> References: <20261028170003.522232767@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 5.10-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: adapted parse_dmc_fw_header() changes to the existing parse_csr_fw_dmc() implementation ] Signed-off-by: Sasha Levin --- drivers/gpu/drm/i915/display/intel_csr.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_csr.c b/drivers/gpu/drm/i915/display/intel_csr.c index d5db16764619c..086ba8720558e 100644 --- a/drivers/gpu/drm/i915/display/intel_csr.c +++ b/drivers/gpu/drm/i915/display/intel_csr.c @@ -439,7 +439,7 @@ static u32 parse_csr_fw_dmc(struct intel_csr *csr, } /* Cache the dmc header info. */ - if (mmio_count > mmio_count_max) { + if (!mmio_count || mmio_count > mmio_count_max) { DRM_ERROR("DMC firmware has wrong mmio count %u\n", mmio_count); return 0; } @@ -454,12 +454,21 @@ static u32 parse_csr_fw_dmc(struct intel_csr *csr, csr->mmioaddr[i] = _MMIO(mmioaddr[i]); csr->mmiodata[i] = mmiodata[i]; } - csr->mmio_count = mmio_count; 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_ERROR("DMC fw_size too large (%u dwords)\n", + dmc_header->fw_size); + return 0; + } + + if (!payload_size) { + DRM_ERROR("DMC firmware has empty payload\n"); + return 0; + } + if (rem_size < payload_size) goto error_truncated; @@ -467,7 +476,6 @@ static u32 parse_csr_fw_dmc(struct intel_csr *csr, DRM_ERROR("DMC FW too big (%u bytes)\n", payload_size); return 0; } - csr->dmc_fw_size = dmc_header->fw_size; csr->dmc_payload = kmalloc(payload_size, GFP_KERNEL); if (!csr->dmc_payload) { @@ -475,6 +483,9 @@ static u32 parse_csr_fw_dmc(struct intel_csr *csr, return 0; } + csr->mmio_count = mmio_count; + csr->dmc_fw_size = dmc_header->fw_size; + payload = (u8 *)(dmc_header) + header_len_bytes; memcpy(csr->dmc_payload, payload, payload_size); -- 2.53.0