From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BDE2C3B637C; Tue, 21 Jul 2026 20:44:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784666647; cv=none; b=co7W/DqI+LlS3PpOgW0krve3M9vTKWBHBWQIf6gDh144fzM1shgKNftbyFTx22f4TkpvMYDchQmSFKDr0obVwTz+3NT1IDZttaU20xvZcQlq3CdZKq8FJ8Ub7xJxbJKCSXV6F4DOX9PiEORLMqBYwyoE555rjDKjGCsrLPyiV3c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784666647; c=relaxed/simple; bh=Ak/87n7CL6cb+t4MfJKbTMgPCDQ6mQCloVJcCK5paDQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Fad0FKr1iLnMdNQ/oFITTz0+HGCQgSL6jzGpr+o9BoGHL/ZnWVeF5NBdajSVGXq/0MSI40KEnOQV1AaWlsJkixw/xVvGUi6BvWaPTU5VXvQfwNXbE90NufZ0Vs/pmfyhriA1nudGIUFSGUKvCfUctj7PiFxzni8TaqLxoJ7tYxk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=iDbGYo9P; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="iDbGYo9P" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2F8921F000E9; Tue, 21 Jul 2026 20:44:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784666646; bh=qttTEfP0XcnTgI6pgeymIpaDrQbetjmS1a1+4bZ446Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=iDbGYo9PMoI09Fv3ZVYFUhmkjYTjswNV/pdewKGWxsbrU4TbPhligOSXcYIYJ7kQP nyGgUG0AI2bXqg8ZkWRisYvPYT6UGCe7WGaybrL7GkTBOvuaJQ748jC8/8Dyel38hs C1LBYWraV7NMZfr4zu0Z8rU+xysOtBXZaIyvOEC8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Weiming Shi , Xiang Mei , Jani Nikula , Sasha Levin Subject: [PATCH 6.6 0762/1266] drm/edid: fix OOB read in drm_parse_tiled_block() Date: Tue, 21 Jul 2026 17:19:59 +0200 Message-ID: <20260721152458.916273287@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152441.786066624@linuxfoundation.org> References: <20260721152441.786066624@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xiang Mei [ Upstream commit faaa1e1155833e7d4ce7e3cfaf64c0d636b190db ] drm_parse_tiled_block() casts the DisplayID block to a struct displayid_tiled_block and reads the full fixed layout up to tile->topology_id[7] without checking block->num_bytes. The DisplayID iterator only validates the declared payload length, so a crafted EDID can advertise a tiled-display block (tag DATA_BLOCK_TILED_DISPLAY, or DATA_BLOCK_2_TILED_DISPLAY_TOPOLOGY for v2.0) with a small num_bytes at the end of a DisplayID extension. The read then runs past the end of the exact-sized kmemdup()'d EDID allocation, a heap out-of-bounds read. Reject blocks shorter than the spec's 22-byte tiled payload before reading the fixed struct, as drm_parse_vesa_mso_data() already does. BUG: KASAN: slab-out-of-bounds in drm_edid_connector_update Read of size 2 at addr ffff888010077700 by task exploit/147 dump_stack_lvl (lib/dump_stack.c:94 ...) print_report (mm/kasan/report.c:378 ...) kasan_report (mm/kasan/report.c:595) drm_edid_connector_update (drivers/gpu/drm/drm_edid.c:7581) bochs_connector_helper_get_modes (drivers/gpu/drm/tiny/bochs.c:574) drm_helper_probe_single_connector_modes (drivers/gpu/drm/drm_probe_helper.c:426) status_store (drivers/gpu/drm/drm_sysfs.c:219) ... vfs_write (fs/read_write.c:595 fs/read_write.c:688) ksys_write (fs/read_write.c:740) Fixes: 40d9b043a89e ("drm/connector: store tile information from displayid (v3)") Reported-by: Weiming Shi Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Xiang Mei Reviewed-by: Jani Nikula Link: https://patch.msgid.link/20260615184737.899892-1-xmei5@asu.edu Signed-off-by: Jani Nikula Signed-off-by: Sasha Levin --- drivers/gpu/drm/drm_edid.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index c6e6e4766c8bf6..dbeae02c76d6a9 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -7279,6 +7279,14 @@ static void drm_parse_tiled_block(struct drm_connector *connector, u8 num_v_tile, num_h_tile; struct drm_tile_group *tg; + /* tiled block payload per spec: cap 1 + topo 3 + size 4 + bezel 5 + id 9 = 22 */ + if (block->num_bytes < 22) { + drm_dbg_kms(connector->dev, + "[CONNECTOR:%d:%s] Unexpected tiled block size %u\n", + connector->base.id, connector->name, block->num_bytes); + return; + } + w = tile->tile_size[0] | tile->tile_size[1] << 8; h = tile->tile_size[2] | tile->tile_size[3] << 8; -- 2.53.0