From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELvluyaaP9kYdBHmbfevbOR+CGEF5UIM+IRQ1dmuOdJbtA3yBCzMe9vXbcoPU0EEuPpC7qfS ARC-Seal: i=1; a=rsa-sha256; t=1521484173; cv=none; d=google.com; s=arc-20160816; b=IJoNtZ4XLNrg8eGcb61AczFklokOhcFJGSnfmsH/XPyIe4yVDYckqejoYUew2deq7C 1YNWh8s8NHthfJpc/UT7EIJbMkpOjCaZcOb19NnGuVkcGq1NG19UgEVsStFC5Z11SuOz Pcq4EJIXscufeH2CxPvPgchtows3kDEHSwsQ5NXc/A/a3CfI6IwVpGYgneO7PCPs3TO8 P0A/m26xpVhIQXsv7vlu5vqjSTHK1cuSZakBL9Lz9geUqB2WwO6xcvMuqp+LDiYVLdQA /99Dn+77Vthqu587+7EaxvP0pQHw1PIl5xuVb7wDYTYKceCrk4Xs0xQrC0CgeBENVr0N 4X/A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=Cehx00yBSIscqUqZi6flj0RmZbu+oybTgCQs9Y2BCxs=; b=AL97MQg/2ZGmbUXOFUJ0bm4ZyMIBMUnQF7+jBWvxdY0LRVQser9M1vPGQszVQ/MLO7 BY26G7xqhl9mU4RJw8RoO2yrJFLCrVLbmAG4p/jsAHYF+WUsZgg5gmetF4y2KTzkoP8T c26H2uxjjZUanGpkyl67NXHLso29cJh3rlUt0CZDNEDuxovT7d4Se5ojmpU2I5L1njSo nvC+nne7HpWqGRrpdK0km7FzLklAHH1nm1J0X4mIE9q6K1pt7ncUjXQhH0t9abBWusjU WBGFwHh2RhsdFkNF4aivaSAvbGnnMl8UM6nGgXqorUY6F/MHn8Qkvaaicy/qrYPyfPfT 6+QA== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pierre Moreau , Lukas Wunner , Ben Skeggs Subject: [PATCH 4.14 17/41] drm/nouveau/bl: Fix oops on driver unbind Date: Mon, 19 Mar 2018 19:08:17 +0100 Message-Id: <20180319180733.382875577@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180319180732.195217948@linuxfoundation.org> References: <20180319180732.195217948@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1595391788434756898?= X-GMAIL-MSGID: =?utf-8?q?1595391788434756898?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Lukas Wunner commit 76f2e2bc627f7d08360ac731b6277d744d4eb599 upstream. Unbinding nouveau on a dual GPU MacBook Pro oopses because we iterate over the bl_connectors list in nouveau_backlight_exit() but skipped initializing it in nouveau_backlight_init(). Stacktrace for posterity: BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 IP: nouveau_backlight_exit+0x2b/0x70 [nouveau] nouveau_display_destroy+0x29/0x80 [nouveau] nouveau_drm_unload+0x65/0xe0 [nouveau] drm_dev_unregister+0x3c/0xe0 [drm] drm_put_dev+0x2e/0x60 [drm] nouveau_drm_device_remove+0x47/0x70 [nouveau] pci_device_remove+0x36/0xb0 device_release_driver_internal+0x157/0x220 driver_detach+0x39/0x70 bus_remove_driver+0x51/0xd0 pci_unregister_driver+0x2a/0xa0 nouveau_drm_exit+0x15/0xfb0 [nouveau] SyS_delete_module+0x18c/0x290 system_call_fast_compare_end+0xc/0x6f Fixes: b53ac1ee12a3 ("drm/nouveau/bl: Do not register interface if Apple GMUX detected") Cc: stable@vger.kernel.org # v4.10+ Cc: Pierre Moreau Signed-off-by: Lukas Wunner Signed-off-by: Ben Skeggs Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/nouveau/nouveau_backlight.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/gpu/drm/nouveau/nouveau_backlight.c +++ b/drivers/gpu/drm/nouveau/nouveau_backlight.c @@ -268,13 +268,13 @@ nouveau_backlight_init(struct drm_device struct nvif_device *device = &drm->client.device; struct drm_connector *connector; + INIT_LIST_HEAD(&drm->bl_connectors); + if (apple_gmux_present()) { NV_INFO(drm, "Apple GMUX detected: not registering Nouveau backlight interface\n"); return 0; } - INIT_LIST_HEAD(&drm->bl_connectors); - list_for_each_entry(connector, &dev->mode_config.connector_list, head) { if (connector->connector_type != DRM_MODE_CONNECTOR_LVDS && connector->connector_type != DRM_MODE_CONNECTOR_eDP)