From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1D391C433F5 for ; Thu, 17 Mar 2022 17:20:06 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 99F0110E626; Thu, 17 Mar 2022 17:20:05 +0000 (UTC) Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by gabe.freedesktop.org (Postfix) with ESMTPS id 236BF10E601 for ; Thu, 17 Mar 2022 17:20:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1647537604; x=1679073604; h=from:to:subject:date:message-id:in-reply-to:references: mime-version:content-transfer-encoding; bh=/S+DrFfPc0l+OY0y/9bEW8OMe2iwRTUfkr1uPMQLgWc=; b=INujcDJux/kBI4Pt6n4QCvXJYPawshKrMlKR4PgsqjY0UtZ/IPPrkfXy Dx79Lj41gYwj7SuLpH2q0AZ3/Xrp7WTLWonTBzeoB6mCuQ+dE25VXgsjX auiaLHAhnVV9rqEqclhgW2WlCaBXHY+pgxsLta+cPwb/icXqR9zztdK76 ekIcD9XyYtZenqsmm/AumjGMCD8mm5cZKmL8m6t345l/kuyqpiEagoP9a mI2S96KahhAFCXCTk4fAEu8d6V5lCWWvCNaKX68Mk/QWSfXyCWZ//KyrY srmPpR+TJbojhA2m+KrEy5cD708To5sUWBUC7PZtjeY7uhP4hTXUeqEcL Q==; X-IronPort-AV: E=McAfee;i="6200,9189,10289"; a="343359118" X-IronPort-AV: E=Sophos;i="5.90,188,1643702400"; d="scan'208";a="343359118" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Mar 2022 10:20:03 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.90,188,1643702400"; d="scan'208";a="635434482" Received: from stinkpipe.fi.intel.com (HELO stinkbox) ([10.237.72.151]) by FMSMGA003.fm.intel.com with SMTP; 17 Mar 2022 10:20:01 -0700 Received: by stinkbox (sSMTP sendmail emulation); Thu, 17 Mar 2022 19:20:00 +0200 From: Ville Syrjala To: intel-gfx@lists.freedesktop.org Date: Thu, 17 Mar 2022 19:19:41 +0200 Message-Id: <20220317171948.10400-5-ville.syrjala@linux.intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220317171948.10400-1-ville.syrjala@linux.intel.com> References: <20220317171948.10400-1-ville.syrjala@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Intel-gfx] [PATCH 04/11] drm/i915/bios: Validate LFP data table pointers X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" From: Ville Syrjälä Make sure the LFP data table pointers sane. Sensible looking table entries, evetything points correctly into the data block, etc. Signed-off-by: Ville Syrjälä --- drivers/gpu/drm/i915/display/intel_bios.c | 82 ++++++++++++++++++++++- 1 file changed, 81 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c index 777339f5dd79..29953996a474 100644 --- a/drivers/gpu/drm/i915/display/intel_bios.c +++ b/drivers/gpu/drm/i915/display/intel_bios.c @@ -153,6 +153,86 @@ static u32 block_offset(const void *bdb, enum bdb_block_id section_id) return block - bdb; } +/* size of the block excluding the header */ +static u32 block_size(const void *bdb, enum bdb_block_id section_id) +{ + const void *block; + + block = find_raw_section(bdb, section_id); + if (!block) + return 0; + + return get_blocksize(block); +} + +static bool validate_lfp_data_ptrs(const void *bdb, + const struct bdb_lvds_lfp_data_ptrs *ptrs) +{ + int fp_timing_size, dvo_timing_size, panel_pnp_id_size; + int data_block_size, lfp_data_size; + int i; + + data_block_size = block_size(bdb, BDB_LVDS_LFP_DATA); + if (data_block_size == 0) + return false; + + /* always 3 indicating the presence of fp_timing+dvo_timing+panel_pnp_id */ + if (ptrs->lvds_entries != 3) + return false; + + fp_timing_size = ptrs->ptr[0].fp_timing.table_size; + dvo_timing_size = ptrs->ptr[0].dvo_timing.table_size; + panel_pnp_id_size = ptrs->ptr[0].panel_pnp_id.table_size; + + /* fp_timing has variable size */ + if (fp_timing_size < 32 || + dvo_timing_size != sizeof(struct lvds_dvo_timing) || + panel_pnp_id_size != sizeof(struct lvds_pnp_id)) + return false; + + lfp_data_size = ptrs->ptr[1].fp_timing.offset - ptrs->ptr[0].fp_timing.offset; + if (16 * lfp_data_size > data_block_size) + return false; + + /* + * Except for vlv/chv machines all real VBTs seem to have 6 + * unaccounted bytes in the fp_timing table. And it doesn't + * appear to be a really intentional hole as the fp_timing + * 0xffff terminator is always within those 6 missing bytes. + */ + if (fp_timing_size + dvo_timing_size + panel_pnp_id_size != lfp_data_size && + fp_timing_size + 6 + dvo_timing_size + panel_pnp_id_size != lfp_data_size) + return false; + + if (ptrs->ptr[0].fp_timing.offset + fp_timing_size > ptrs->ptr[0].dvo_timing.offset || + ptrs->ptr[0].dvo_timing.offset + dvo_timing_size != ptrs->ptr[0].panel_pnp_id.offset || + ptrs->ptr[0].panel_pnp_id.offset + panel_pnp_id_size != lfp_data_size) + return false; + + /* make sure the table entries have uniform size */ + for (i = 1; i < 16; i++) { + if (ptrs->ptr[i].fp_timing.table_size != fp_timing_size || + ptrs->ptr[i].dvo_timing.table_size != dvo_timing_size || + ptrs->ptr[i].panel_pnp_id.table_size != panel_pnp_id_size) + return false; + + if (ptrs->ptr[i].fp_timing.offset - ptrs->ptr[i-1].fp_timing.offset != lfp_data_size || + ptrs->ptr[i].dvo_timing.offset - ptrs->ptr[i-1].dvo_timing.offset != lfp_data_size || + ptrs->ptr[i].panel_pnp_id.offset - ptrs->ptr[i-1].panel_pnp_id.offset != lfp_data_size) + return false; + } + + /* make sure the tables fit inside the data block */ + for (i = 0; i < 16; i++) { + if (ptrs->ptr[i].fp_timing.offset + fp_timing_size > data_block_size || + ptrs->ptr[i].dvo_timing.offset + dvo_timing_size > data_block_size || + ptrs->ptr[i].panel_pnp_id.offset + panel_pnp_id_size > data_block_size) + return false; + } + + return true; +} + /* make the data table offsets relative to the data block */ static bool fixup_lfp_data_ptrs(const void *bdb, void *ptrs_block) { @@ -173,7 +253,7 @@ static bool fixup_lfp_data_ptrs(const void *bdb, void *ptrs_block) ptrs->ptr[i].panel_pnp_id.offset -= offset; } - return true; + return validate_lfp_data_ptrs(bdb, ptrs); } static const void * -- 2.34.1