From patchwork Wed Jun 2 03:41:36 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dongliang Mu X-Patchwork-Id: 12292763 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E3211C47083 for ; Wed, 2 Jun 2021 03:42:54 +0000 (UTC) Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 93D25613CA for ; Wed, 2 Jun 2021 03:42:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 93D25613CA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=alsa-devel-bounces@alsa-project.org Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id 4F42416D6; Wed, 2 Jun 2021 05:42:01 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 4F42416D6 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1622605371; bh=2Mz4CL+hcmZfP6hnTper68o0ITZ3eyyHnnwv7B3fgaM=; h=From:To:Subject:Date:Cc:List-Id:List-Unsubscribe:List-Archive: List-Post:List-Help:List-Subscribe:From; b=jYVKNWR3VfV9Ah5rDYSYAFj/DQHYvFtbfeCsZhNalU0uilufdFG4kSX2PmHqiNMOS W4PGWc/EACXp4SdJVbvQ9hkWSDhVPhd6woCdYdzMuFk6RWahyRL9xpTjRs/BwDC2fZ jHzKHKOfg5WpbQKblS2eC6i2rha9jTkuWATQzj0w= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id D1305F802A9; Wed, 2 Jun 2021 05:42:00 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 8A146F80424; Wed, 2 Jun 2021 05:41:58 +0200 (CEST) Received: from mail-pf1-x430.google.com (mail-pf1-x430.google.com [IPv6:2607:f8b0:4864:20::430]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id 012DEF80273 for ; Wed, 2 Jun 2021 05:41:50 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 012DEF80273 Authentication-Results: alsa1.perex.cz; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="PyV8FeSK" Received: by mail-pf1-x430.google.com with SMTP id z26so1128084pfj.5 for ; Tue, 01 Jun 2021 20:41:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=zLdktgE0a9sEXZ0/b+s3AebnOjlZIpwVaCTKFoWaY6o=; b=PyV8FeSKyEIVaDpLD1OQklsC0+U/xDfysW1/zZXRwfV+KdD6NggGTMgx0BhlkyFcVW SuRX+ExKpACmEe4VXNzThsolvdMl99oWRC4cLxxUJxJlxkG0WEAH1BeLWZGowj3e2+g6 FJO0au3vJfJ7e2KFHuA73+gMVKDUzYq2QluuHh17e5HzHEMzFAru7FLzovFHeQfaJo9T vCQqxmaUsbR50lSrCAYy3QdXiuzV+sGsjOpaavnZMj/xQtrfLs+PJJ7/WqjISF4F35zF N2NNaZShZivIOJpEWbo8EQErq/+YBkkSsgADbfH0ePpBC4RyEdspM4G+RqHvPec+CQgF o7zA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=zLdktgE0a9sEXZ0/b+s3AebnOjlZIpwVaCTKFoWaY6o=; b=NOquQx7g0bjYfcYwrT5F6kfcbYgcv+iqo8Lx8WxZKEgRGRrna0TpzZalWN1IAl0KAe Bun1ZojGzykfIyVSVxFTHiZtCaabhFVxgr8KGZNhua9JHsFIWVpW7X11/tp97/60hDDH Z+ohqpC6sp3Hm43hZFlWaHA9M3ugi3PulvR1xFa3hGXmp4vRU25z4EewGVh2QxILpoQM rS4tGI8yC6WLxN1G/T3C01HCYCpi7nWZZwrAb8rnLAXqMIu64LZ0IFCuAd2u9edWL2RM byZ4eZyX8G5gvTnzHFNClAnU9K/PSMno1hQAt9VseMReuoMBC30T8Cv+qpG3FbY0jpqF dYHA== X-Gm-Message-State: AOAM5324RYOswE3PLYpLZyaGvWUUyHUMn38zJeArRMQaTnHNg81yyJaW PHBHR9M73jsFQAggFDB9SAY= X-Google-Smtp-Source: ABdhPJzPeLvDeBppfezgwtWuGF9uxgIOTAtzej3GgkpTc/DSKL2YdMFF0UIb8N/mqAv4ufvrNDH0ew== X-Received: by 2002:aa7:80d3:0:b029:28e:f117:4961 with SMTP id a19-20020aa780d30000b029028ef1174961mr25291555pfn.37.1622605308627; Tue, 01 Jun 2021 20:41:48 -0700 (PDT) Received: from localhost.localdomain ([45.135.186.140]) by smtp.gmail.com with ESMTPSA id 141sm10746460pgf.20.2021.06.01.20.41.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 01 Jun 2021 20:41:48 -0700 (PDT) From: Dongliang Mu To: perex@perex.cz, tiwai@suse.com, dan.carpenter@oracle.com, alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] ALSA: control led: fix memory leak in snd_ctl_led_register Date: Wed, 2 Jun 2021 11:41:36 +0800 Message-Id: <20210602034136.2762497-1-mudongliangabcd@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Cc: Dongliang Mu , syzbot+08a7d8b51ea048a74ffb@syzkaller.appspotmail.com X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" The snd_ctl_led_sysfs_add and snd_ctl_led_sysfs_remove should contain the refcount operations in pair. However, snd_ctl_led_sysfs_remove fails to decrease the refcount to zero, which causes device_release never to be invoked. This leads to memory leak to some resources, like struct device_private. In addition, we also free some other similar memory leaks in snd_ctl_led_init/snd_ctl_led_exit. Fix this by replacing device_del to device_unregister in snd_ctl_led_sysfs_remove/snd_ctl_led_init/snd_ctl_led_exit. Note that, when CONFIG_DEBUG_KOBJECT_RELEASE is enabled, put_device will call kobject_release and delay the release of kobject, which will cause use-after-free when the memory backing the kobject is freed at once. Reported-by: syzbot+08a7d8b51ea048a74ffb@syzkaller.appspotmail.com Fixes: a135dfb5de1 ("ALSA: led control - add sysfs kcontrol LED marking layer") Signed-off-by: Dongliang Mu Reviewed-by: Dan Carpenter --- v1->v2: fix other similar memory leaks; move kfree(led_card) to a release function. sound/core/control_led.c | 33 ++++++++++++++++++++++++++------- 1 file changed, 26 insertions(+), 7 deletions(-) diff --git a/sound/core/control_led.c b/sound/core/control_led.c index 25f57c14f294..a90e31dbde61 100644 --- a/sound/core/control_led.c +++ b/sound/core/control_led.c @@ -17,6 +17,9 @@ MODULE_LICENSE("GPL"); #define MAX_LED (((SNDRV_CTL_ELEM_ACCESS_MIC_LED - SNDRV_CTL_ELEM_ACCESS_SPK_LED) \ >> SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) + 1) +#define to_led_card_dev(_dev) \ + container_of(_dev, struct snd_ctl_led_card, dev) + enum snd_ctl_led_mode { MODE_FOLLOW_MUTE = 0, MODE_FOLLOW_ROUTE, @@ -371,6 +374,21 @@ static void snd_ctl_led_disconnect(struct snd_card *card) snd_ctl_led_refresh(); } +static void snd_ctl_led_card_release(struct device *dev) +{ + struct snd_ctl_led_card *led_card = to_led_card_dev(dev); + + kfree(led_card); +} + +static void snd_ctl_led_release(struct device *dev) +{ +} + +static void snd_ctl_led_dev_release(struct device *dev) +{ +} + /* * sysfs */ @@ -663,6 +681,7 @@ static void snd_ctl_led_sysfs_add(struct snd_card *card) led_card->number = card->number; led_card->led = led; device_initialize(&led_card->dev); + led_card->dev.release = snd_ctl_led_card_release; if (dev_set_name(&led_card->dev, "card%d", card->number) < 0) goto cerr; led_card->dev.parent = &led->dev; @@ -681,7 +700,6 @@ static void snd_ctl_led_sysfs_add(struct snd_card *card) put_device(&led_card->dev); cerr2: printk(KERN_ERR "snd_ctl_led: unable to add card%d", card->number); - kfree(led_card); } } @@ -700,8 +718,7 @@ static void snd_ctl_led_sysfs_remove(struct snd_card *card) snprintf(link_name, sizeof(link_name), "led-%s", led->name); sysfs_remove_link(&card->ctl_dev.kobj, link_name); sysfs_remove_link(&led_card->dev.kobj, "card"); - device_del(&led_card->dev); - kfree(led_card); + device_unregister(&led_card->dev); led->cards[card->number] = NULL; } } @@ -723,6 +740,7 @@ static int __init snd_ctl_led_init(void) device_initialize(&snd_ctl_led_dev); snd_ctl_led_dev.class = sound_class; + snd_ctl_led_dev.release = snd_ctl_led_dev_release; dev_set_name(&snd_ctl_led_dev, "ctl-led"); if (device_add(&snd_ctl_led_dev)) { put_device(&snd_ctl_led_dev); @@ -733,15 +751,16 @@ static int __init snd_ctl_led_init(void) INIT_LIST_HEAD(&led->controls); device_initialize(&led->dev); led->dev.parent = &snd_ctl_led_dev; + led->dev.release = snd_ctl_led_release; led->dev.groups = snd_ctl_led_dev_attr_groups; dev_set_name(&led->dev, led->name); if (device_add(&led->dev)) { put_device(&led->dev); for (; group > 0; group--) { led = &snd_ctl_leds[group - 1]; - device_del(&led->dev); + device_unregister(&led->dev); } - device_del(&snd_ctl_led_dev); + device_unregister(&snd_ctl_led_dev); return -ENOMEM; } } @@ -767,9 +786,9 @@ static void __exit snd_ctl_led_exit(void) } for (group = 0; group < MAX_LED; group++) { led = &snd_ctl_leds[group]; - device_del(&led->dev); + device_unregister(&led->dev); } - device_del(&snd_ctl_led_dev); + device_unregister(&snd_ctl_led_dev); snd_ctl_led_clean(NULL); }