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 X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 384DFC43441 for ; Mon, 26 Nov 2018 08:28:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F2CCA20672 for ; Mon, 26 Nov 2018 08:28:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="rhz7X5ad" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F2CCA20672 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726397AbeKZTVv (ORCPT ); Mon, 26 Nov 2018 14:21:51 -0500 Received: from mail-pf1-f196.google.com ([209.85.210.196]:39122 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726176AbeKZTVu (ORCPT ); Mon, 26 Nov 2018 14:21:50 -0500 Received: by mail-pf1-f196.google.com with SMTP id c72so6214550pfc.6; Mon, 26 Nov 2018 00:28:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=vSeCuUAxYMii8wBXKucH4lrypxlld5OmNONR0hywUX0=; b=rhz7X5adDw1ynPwzfOhmiqLBj6DdtI7l/67+WQhU35sDgTQJ+JBffY9u2D/SXbc1Aw eDrk+3LweZmqcPnUU0SniTAiVv1qGWqkUGRWaGXUsk273aawEd7KnEecZhbfypi85mwc MrH2qet/nnhii/CUwpGr2CnYlDa46QAqLPQ7CwfBgEYqJVOhNVhKZmdoggS0oK8oGMS2 uAjGVsfN5xD4yP4g821pouxlwAt4P4QOdlA/VuAO6dMiNx7dVXnb2gul+CwzXBV0023g tzr3I7EhBKwNEEIH6XafDMyEeYkWFyFBylgdp9KY+/CYiMl6Y/Z3gcPCeN6jDXvC9e1I eDug== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-transfer-encoding; bh=vSeCuUAxYMii8wBXKucH4lrypxlld5OmNONR0hywUX0=; b=X7sFG68CPyB/Vf+R+Y8u6NtSMy0sJJSQTruQyYCYR8IBvI+b2zvuAE/ZjLARXvnjpB A1yWEZndhAIEdCRP+Nhn0cXYxxnOzLJJrfkYXUo9NVWhvq0+/Xsbv/zm9/Gn1t779td8 EMuN+OyESBSG4E1+j+hNWh/uIZSiruPq6yoMo78VTRnsAoNzzwqHaAuYr9INhO76lZlV lKZ2StQ2NWe8Oq7WMry302sk2nWeGXMVr6HRyxpP6XUOFLv25pJIbgQP+E4sX1u77ps8 h3LNAFMs05sVeFuaxu8y5R07DYssMBV83SrXFY6fco6YnqGiDwGilkUsWylieQ7q8p/1 Q6SQ== X-Gm-Message-State: AA+aEWbGEPuGbNVNDrTJtOrxLQcd1nfT4EpL73SD26EXtJ0KOMvmRiuM T8y1E4bHUEeVOpfSeHoe5mMQpN6xN+4= X-Google-Smtp-Source: AFSGD/XNxvydAcESuO4wiWRb4ww3JkX/+15vAq3hL6/0jAx8enn1X+hwk3SsdWuulkeCN5BxF9Q0OQ== X-Received: by 2002:a62:2a4b:: with SMTP id q72mr11063217pfq.61.1543220907571; Mon, 26 Nov 2018 00:28:27 -0800 (PST) Received: from bbox-2.seo.corp.google.com ([2401:fa00:d:0:98f1:8b3d:1f37:3e8]) by smtp.gmail.com with ESMTPSA id j197sm82846611pgc.76.2018.11.26.00.28.24 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 26 Nov 2018 00:28:26 -0800 (PST) From: Minchan Kim To: Andrew Morton Cc: LKML , Sergey Senozhatsky , Minchan Kim , stable@vger.kernel.org Subject: [PATCH v2 2/7] zram: fix double free backing device Date: Mon, 26 Nov 2018 17:28:08 +0900 Message-Id: <20181126082813.81977-3-minchan@kernel.org> X-Mailer: git-send-email 2.20.0.rc0.387.gc7a69e6b6c-goog In-Reply-To: <20181126082813.81977-1-minchan@kernel.org> References: <20181126082813.81977-1-minchan@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If blkdev_get fails, we shouldn't do blkdev_put. Otherwise, kernel emits below log. This patch fixes it. [ 31.073006] WARNING: CPU: 0 PID: 1893 at fs/block_dev.c:1828 blkdev_put+0x105/0x120 [ 31.075104] Modules linked in: [ 31.075898] CPU: 0 PID: 1893 Comm: swapoff Not tainted 4.19.0+ #453 [ 31.077484] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 31.079589] RIP: 0010:blkdev_put+0x105/0x120 [ 31.080606] Code: 48 c7 80 a0 00 00 00 00 00 00 00 48 c7 c7 40 e7 40 96 e8 6e 47 73 00 48 8b bb e0 00 00 00 e9 2c ff ff ff 0f 0b e9 75 ff ff ff <0f> 0b e9 5a ff ff ff 48 c7 80 a0 00 00 00 00 00 00 00 eb 87 0f 1f [ 31.085080] RSP: 0018:ffffb409005c7ed0 EFLAGS: 00010297 [ 31.086383] RAX: ffff9779fe5a8040 RBX: ffff9779fbc17300 RCX: 00000000b9fc37a4 [ 31.088105] RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffffff9640e740 [ 31.089850] RBP: ffff9779fbc17318 R08: ffffffff95499a89 R09: 0000000000000004 [ 31.091201] R10: ffffb409005c7e50 R11: 7a9ef6088ff4d4a1 R12: 0000000000000083 [ 31.092276] R13: ffff9779fe607b98 R14: 0000000000000000 R15: ffff9779fe607a38 [ 31.093355] FS: 00007fc118d9b840(0000) GS:ffff9779fc600000(0000) knlGS:0000000000000000 [ 31.094582] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 31.095541] CR2: 00007fc11894b8dc CR3: 00000000339f6001 CR4: 0000000000160ef0 [ 31.096781] Call Trace: [ 31.097212] __x64_sys_swapoff+0x46d/0x490 [ 31.097914] do_syscall_64+0x5a/0x190 [ 31.098550] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 31.099402] RIP: 0033:0x7fc11843ec27 [ 31.100013] Code: 73 01 c3 48 8b 0d 71 62 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 a8 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 41 62 2c 00 f7 d8 64 89 01 48 [ 31.103149] RSP: 002b:00007ffdf69be648 EFLAGS: 00000206 ORIG_RAX: 00000000000000a8 [ 31.104425] RAX: ffffffffffffffda RBX: 00000000011d98c0 RCX: 00007fc11843ec27 [ 31.105627] RDX: 0000000000000001 RSI: 0000000000000001 RDI: 00000000011d98c0 [ 31.106847] RBP: 0000000000000001 R08: 00007ffdf69be690 R09: 0000000000000001 [ 31.108038] R10: 00000000000002b1 R11: 0000000000000206 R12: 0000000000000001 [ 31.109231] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 31.110433] irq event stamp: 4466 [ 31.111001] hardirqs last enabled at (4465): [] __free_pages_ok+0x1e3/0x490 [ 31.112437] hardirqs last disabled at (4466): [] trace_hardirqs_off_thunk+0x1a/0x1c [ 31.113973] softirqs last enabled at (3420): [] __do_softirq+0x333/0x446 [ 31.115364] softirqs last disabled at (3407): [] irq_exit+0xd1/0xe0 Cc: stable@vger.kernel.org # 4.14+ Signed-off-by: Minchan Kim --- drivers/block/zram/zram_drv.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 472027eaed60..514f5aaf6eff 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -387,8 +387,10 @@ static ssize_t backing_dev_store(struct device *dev, bdev = bdgrab(I_BDEV(inode)); err = blkdev_get(bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL, zram); - if (err < 0) + if (err < 0) { + bdev = NULL; goto out; + } nr_pages = i_size_read(inode) >> PAGE_SHIFT; bitmap_sz = BITS_TO_LONGS(nr_pages) * sizeof(long); -- 2.20.0.rc0.387.gc7a69e6b6c-goog