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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BE266ECAAD5 for ; Tue, 6 Sep 2022 14:10:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241009AbiIFOIi (ORCPT ); Tue, 6 Sep 2022 10:08:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58892 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240902AbiIFOHa (ORCPT ); Tue, 6 Sep 2022 10:07:30 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E827585F86; Tue, 6 Sep 2022 06:45:40 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 474C2CE1779; Tue, 6 Sep 2022 13:44:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C5917C433D6; Tue, 6 Sep 2022 13:44:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1662471876; bh=PkANjPyEN6TSj19BYKsh3KOyw4fzz4r1byqtdqWJq2I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZHdkqg3Ld1w+TboZ3Y0+xXGNLlFCd/ofXo8NwlEczL4gmrk3LwQNElr8h0Ifx96X5 2xzXQDNccqp43YJwWaLCbEXIqgXfXLjJEhWXqUmz+hSY4Yb0zJp4VB+qaTp0ndj+l/ TZuSJbBHv6vDnw0SN/GRNcowp6X/w5ghIu0PpdJo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, =?UTF-8?q?=C5=81ukasz=20Bartosik?= , Radhakrishna Sripada , Jani Nikula , Rodrigo Vivi , Sasha Levin Subject: [PATCH 5.19 038/155] drm/i915: fix null pointer dereference Date: Tue, 6 Sep 2022 15:29:46 +0200 Message-Id: <20220906132831.034858111@linuxfoundation.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220906132829.417117002@linuxfoundation.org> References: <20220906132829.417117002@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Łukasz Bartosik [ Upstream commit 458ec0c8f35963626ccd51c3d50b752de5f1b9d4 ] Asus chromebook CX550 crashes during boot on v5.17-rc1 kernel. The root cause is null pointer defeference of bi_next in tgl_get_bw_info() in drivers/gpu/drm/i915/display/intel_bw.c. BUG: kernel NULL pointer dereference, address: 000000000000002e PGD 0 P4D 0 Oops: 0002 [#1] PREEMPT SMP NOPTI CPU: 0 PID: 1 Comm: swapper/0 Tainted: G U 5.17.0-rc1 Hardware name: Google Delbin/Delbin, BIOS Google_Delbin.13672.156.3 05/14/2021 RIP: 0010:tgl_get_bw_info+0x2de/0x510 ... [ 2.554467] Call Trace: [ 2.554467] [ 2.554467] intel_bw_init_hw+0x14a/0x434 [ 2.554467] ? _printk+0x59/0x73 [ 2.554467] ? _dev_err+0x77/0x91 [ 2.554467] i915_driver_hw_probe+0x329/0x33e [ 2.554467] i915_driver_probe+0x4c8/0x638 [ 2.554467] i915_pci_probe+0xf8/0x14e [ 2.554467] ? _raw_spin_unlock_irqrestore+0x12/0x2c [ 2.554467] pci_device_probe+0xaa/0x142 [ 2.554467] really_probe+0x13f/0x2f4 [ 2.554467] __driver_probe_device+0x9e/0xd3 [ 2.554467] driver_probe_device+0x24/0x7c [ 2.554467] __driver_attach+0xba/0xcf [ 2.554467] ? driver_attach+0x1f/0x1f [ 2.554467] bus_for_each_dev+0x8c/0xc0 [ 2.554467] bus_add_driver+0x11b/0x1f7 [ 2.554467] driver_register+0x60/0xea [ 2.554467] ? mipi_dsi_bus_init+0x16/0x16 [ 2.554467] i915_init+0x2c/0xb9 [ 2.554467] ? mipi_dsi_bus_init+0x16/0x16 [ 2.554467] do_one_initcall+0x12e/0x2b3 [ 2.554467] do_initcall_level+0xd6/0xf3 [ 2.554467] do_initcalls+0x4e/0x79 [ 2.554467] kernel_init_freeable+0xed/0x14d [ 2.554467] ? rest_init+0xc1/0xc1 [ 2.554467] kernel_init+0x1a/0x120 [ 2.554467] ret_from_fork+0x1f/0x30 [ 2.554467] ... Kernel panic - not syncing: Fatal exception Fixes: c64a9a7c05be ("drm/i915: Update memory bandwidth formulae") Signed-off-by: Łukasz Bartosik Reviewed-by: Radhakrishna Sripada Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/20220201153354.11971-1-lukasz.bartosik@semihalf.com (cherry picked from commit c247cd03898c4c43c3bce6d4014730403bc13032) Signed-off-by: Rodrigo Vivi Signed-off-by: Sasha Levin --- drivers/gpu/drm/i915/display/intel_bw.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_bw.c b/drivers/gpu/drm/i915/display/intel_bw.c index 37bd7b17f3d0b..f2fad199e2e0b 100644 --- a/drivers/gpu/drm/i915/display/intel_bw.c +++ b/drivers/gpu/drm/i915/display/intel_bw.c @@ -404,15 +404,17 @@ static int tgl_get_bw_info(struct drm_i915_private *dev_priv, const struct intel int clpchgroup; int j; - if (i < num_groups - 1) - bi_next = &dev_priv->max_bw[i + 1]; - clpchgroup = (sa->deburst * qi.deinterleave / num_channels) << i; - if (i < num_groups - 1 && clpchgroup < clperchgroup) - bi_next->num_planes = (ipqdepth - clpchgroup) / clpchgroup + 1; - else - bi_next->num_planes = 0; + if (i < num_groups - 1) { + bi_next = &dev_priv->max_bw[i + 1]; + + if (clpchgroup < clperchgroup) + bi_next->num_planes = (ipqdepth - clpchgroup) / + clpchgroup + 1; + else + bi_next->num_planes = 0; + } bi->num_qgv_points = qi.num_points; bi->num_psf_gv_points = qi.num_psf_points; -- 2.35.1