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 4D65DC433F5 for ; Mon, 2 May 2022 13:10:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1385185AbiEBNNq (ORCPT ); Mon, 2 May 2022 09:13:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41864 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1385171AbiEBNNi (ORCPT ); Mon, 2 May 2022 09:13:38 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 066E0192BC for ; Mon, 2 May 2022 06:10:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1651497009; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=9jDUUd5wUXo34iLbUpw6jbiGIGpSLkimligm8emfXD8=; b=fmuM8T/JCLPWRDaPoaJMCJyz44l67WXmQGWtyb/uqAQSHi60cynzTyNc6XOH0WVoW9d7vj BZM0TpnN2vHaG1sfrEHdE4sC3qbaArWotfJG1Ct24/IjLKQLZfzdv61a/Oa1Ah8lzKigte whxre7DC76nhUwOdfYpcgDakokBIs9c= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-225-blPzQCvuPB6LQjjxUkOG5Q-1; Mon, 02 May 2022 09:10:05 -0400 X-MC-Unique: blPzQCvuPB6LQjjxUkOG5Q-1 Received: by mail-wm1-f70.google.com with SMTP id g14-20020a1c4e0e000000b0039425ef54d6so2184233wmh.9 for ; Mon, 02 May 2022 06:10:03 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=9jDUUd5wUXo34iLbUpw6jbiGIGpSLkimligm8emfXD8=; b=wRL++o91R7e+LRZsDeDK74JzC9DGCmlaUT/7+54qWNZQgXoUD4drnFAb+h40YNinbH hRQ6zz6o2NfTYI/ef713Ej1ZKxuXiHgmmElCMCsEh1xtl13Olj2JarH6c/6vcR2ahwcp 1DRdK+M42HHmyVtCzCz+yIWCfO397UzF72pWDoe41lhYXAmOJHiCWm28AiNQfes2nYsM iRFd6onubjpyRS2eMtI2KlEKq5hR3jU2fyTyzwXwbFGHgXB7DBwiuerunO+O//Lcc+q8 3K0CpmUV4A8szlWYHT1RdG833D8kvHBGvGl2MvDWCyWpz+EuaxNUywNPQWmoeVlXG6Ki lK5A== X-Gm-Message-State: AOAM5338u3bwPTRlxfq+LqOA/A02/t8APrQGcjHAh+Gfu8at5AWMXsIy PSxbs2h2GVkwB6NxTxj6OwkZ1gqxcjituqCqPmCJaKsahP+W5RKMzV8X36mm8AQ3HmbrP9nSvIY 4XNMDG4yM8KcxHkGPskHTl2ojbRGJfS1sGx3VGLYttmvzAJAhip3PpUxVoqV32mTCuOT8QDrxMJ 8= X-Received: by 2002:adf:d1c9:0:b0:203:c225:d042 with SMTP id b9-20020adfd1c9000000b00203c225d042mr9246079wrd.630.1651497001669; Mon, 02 May 2022 06:10:01 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxOkTguHAtECK69/s/1UYa4VaS8/fQLKinHt0F/MRa24f9/shVWIWvvemP/4uJ44EqjTVqlaQ== X-Received: by 2002:adf:d1c9:0:b0:203:c225:d042 with SMTP id b9-20020adfd1c9000000b00203c225d042mr9246054wrd.630.1651497001394; Mon, 02 May 2022 06:10:01 -0700 (PDT) Received: from minerva.home ([92.176.231.205]) by smtp.gmail.com with ESMTPSA id y16-20020adfc7d0000000b0020adc114136sm9302081wrg.0.2022.05.02.06.10.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 May 2022 06:10:01 -0700 (PDT) From: Javier Martinez Canillas To: linux-kernel@vger.kernel.org Cc: Maxime Ripard , Thomas Zimmermann , Javier Martinez Canillas , Alex Deucher , Changcheng Deng , Daniel Vetter , Guenter Roeck , Helge Deller , Sam Ravnborg , Zhen Lei , Zheyu Ma , dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org Subject: [PATCH 2/2] fbdev: Make fb_release() return -ENODEV if fbdev was unregistered Date: Mon, 2 May 2022 15:09:44 +0200 Message-Id: <20220502130944.363776-3-javierm@redhat.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220502130944.363776-1-javierm@redhat.com> References: <20220502130944.363776-1-javierm@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org A reference to the framebuffer device struct fb_info is stored in the file private data, but this reference could no longer be valid and must not be accessed directly. Instead, the file_fb_info() accessor function must be used since it does sanity checking to make sure that the fb_info is valid. This can happen for example if the fbdev driver was one that is using a framebuffer provided by the system firmware. In that case, the fbdev core could unregister the framebuffer device if a real video driver is probed. Reported-by: Maxime Ripard Signed-off-by: Javier Martinez Canillas --- drivers/video/fbdev/core/fbmem.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index 20d8929df79f..d68097105f93 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -1439,7 +1439,10 @@ fb_release(struct inode *inode, struct file *file) __acquires(&info->lock) __releases(&info->lock) { - struct fb_info * const info = file->private_data; + struct fb_info * const info = file_fb_info(file); + + if (!info) + return -ENODEV; lock_fb_info(info); if (info->fbops->fb_release) -- 2.35.1