From patchwork Fri Jan 27 16:58:34 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Takashi Iwai X-Patchwork-Id: 647765 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 4C077C54EAA for ; Fri, 27 Jan 2023 16:58:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234290AbjA0Q6r (ORCPT ); Fri, 27 Jan 2023 11:58:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53922 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234309AbjA0Q6q (ORCPT ); Fri, 27 Jan 2023 11:58:46 -0500 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DAAE159C5; Fri, 27 Jan 2023 08:58:45 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 707D91F8A4; Fri, 27 Jan 2023 16:58:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1674838724; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=ALfBJc/TQnM76erXqx3WFS5RKW2U4RiO2owBZHKVCn8=; b=eKjVXY6L2bTaysy2dxZYGumxEmgbJgFFV9dWbg2XycKTSNuEReJucdlSDTY4AMPBhorrlL ym3HZYuEHB8Np2ZCFuyBNkUOQ0ktCSNEwFFQhsuygKWszcutdYTfvyXwROWRawcYnBzjEY ExQGRPzh4knFK7qzICuuvSWW3mFTehs= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1674838724; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=ALfBJc/TQnM76erXqx3WFS5RKW2U4RiO2owBZHKVCn8=; b=e0DErOEVvhfTZTI2/NwXWSWXpgYrK2/+9f6tnnXm8Yx6D8A5qtYNTf9vFajXiffEiZNcV3 nE8f0OOcl67HZYDA== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 466AD1336F; Fri, 27 Jan 2023 16:58:44 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id GyqPEMQC1GO1FwAAMHmgww (envelope-from ); Fri, 27 Jan 2023 16:58:44 +0000 From: Takashi Iwai To: Helge Deller Cc: linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Patrik Jakobsson , Thomas Zimmermann Subject: [PATCH] fbdev: Fix invalid page access after closing deferred I/O devices Date: Fri, 27 Jan 2023 17:58:34 +0100 Message-Id: <20230127165834.11387-1-tiwai@suse.de> X-Mailer: git-send-email 2.35.3 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org When a fbdev with deferred I/O is once opened and closed, the dirty pages still remain queued in the pageref list, and eventually later those may be processed in the delayed work. This may lead to a corruption of pages, hitting an Oops. This patch makes sure to cancel the delayed work and clean up the pageref list at closing the device for addressing the bug. A part of the cleanup code is factored out as a new helper function that is called from the common fb_release(). Cc: Signed-off-by: Takashi Iwai Reviewed-by: Patrik Jakobsson Reviewed-by: Patrik Jakobsson --- drivers/video/fbdev/core/fb_defio.c | 10 +++++++++- drivers/video/fbdev/core/fbmem.c | 2 ++ include/linux/fb.h | 1 + 3 files changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c index c730253ab85c..583cbcf09446 100644 --- a/drivers/video/fbdev/core/fb_defio.c +++ b/drivers/video/fbdev/core/fb_defio.c @@ -313,7 +313,7 @@ void fb_deferred_io_open(struct fb_info *info, } EXPORT_SYMBOL_GPL(fb_deferred_io_open); -void fb_deferred_io_cleanup(struct fb_info *info) +void fb_deferred_io_release(struct fb_info *info) { struct fb_deferred_io *fbdefio = info->fbdefio; struct page *page; @@ -327,6 +327,14 @@ void fb_deferred_io_cleanup(struct fb_info *info) page = fb_deferred_io_page(info, i); page->mapping = NULL; } +} +EXPORT_SYMBOL_GPL(fb_deferred_io_release); + +void fb_deferred_io_cleanup(struct fb_info *info) +{ + struct fb_deferred_io *fbdefio = info->fbdefio; + + fb_deferred_io_release(info); kvfree(info->pagerefs); mutex_destroy(&fbdefio->lock); diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index 3a6c8458eb8d..78c4cb5ee7c9 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -1454,6 +1454,8 @@ __releases(&info->lock) struct fb_info * const info = file->private_data; lock_fb_info(info); + if (info->fbdefio) + fb_deferred_io_release(info); if (info->fbops->fb_release) info->fbops->fb_release(info,1); module_put(info->fbops->owner); diff --git a/include/linux/fb.h b/include/linux/fb.h index 96b96323e9cb..73eb1f85ea8e 100644 --- a/include/linux/fb.h +++ b/include/linux/fb.h @@ -662,6 +662,7 @@ extern int fb_deferred_io_init(struct fb_info *info); extern void fb_deferred_io_open(struct fb_info *info, struct inode *inode, struct file *file); +extern void fb_deferred_io_release(struct fb_info *info); extern void fb_deferred_io_cleanup(struct fb_info *info); extern int fb_deferred_io_fsync(struct file *file, loff_t start, loff_t end, int datasync);