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=-10.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,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 33F1CC43387 for ; Fri, 11 Jan 2019 14:42:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 046DE206B6 for ; Fri, 11 Jan 2019 14:42:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1547217771; bh=LE1Di3SxB5ExhGbspW9AAj8GtPuEF83SGNSxZ7p4nmU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=mX3spkb+zgsZeLjU0frXefRWtD2a+adpIkV2jAuoaEeQjRi+47AXuNWK+I4Vl92tj xNxppvVeLpurEkzpQWf5yeyv66ynKXgdWYOl/yyAzDyh1ClvjaCtXOOHFvUJS+d1we Ku/rSllocG5lcvW4mBgw7Lnnjr4IH2aonWHoNOKI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404235AbfAKOmu (ORCPT ); Fri, 11 Jan 2019 09:42:50 -0500 Received: from mail.kernel.org ([198.145.29.99]:35534 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2403847AbfAKOmq (ORCPT ); Fri, 11 Jan 2019 09:42:46 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0DCAD2063F; Fri, 11 Jan 2019 14:42:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1547217765; bh=LE1Di3SxB5ExhGbspW9AAj8GtPuEF83SGNSxZ7p4nmU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=j+s2++qOYfzDU9+tpiaLTG6NyDUDMeYcG3XGWMKuiemUXzMWo3x8syj2CPRtQplm5 RPI66NGqKTDC5r04Q70hKwFiHLnnWtpTQhI3aGXKt+7jmnnRdbxWEZc3o/44QqoavQ 14/y67h5+PXVpnfP9P3oRQDP7Vvw6juu9fedr0TI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Minchan Kim , Sergey Senozhatsky , Joey Pabalinas , Andrew Morton , Linus Torvalds Subject: [PATCH 4.20 04/65] zram: fix double free backing device Date: Fri, 11 Jan 2019 15:14:50 +0100 Message-Id: <20190111131056.679232043@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190111131055.331350141@linuxfoundation.org> References: <20190111131055.331350141@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ From: Minchan Kim commit 5547932dc67a48713eece4fa4703bfdf0cfcb818 upstream. If blkdev_get fails, we shouldn't do blkdev_put. Otherwise, kernel emits below log. This patch fixes it. WARNING: CPU: 0 PID: 1893 at fs/block_dev.c:1828 blkdev_put+0x105/0x120 Modules linked in: CPU: 0 PID: 1893 Comm: swapoff Not tainted 4.19.0+ #453 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 RIP: 0010:blkdev_put+0x105/0x120 Call Trace: __x64_sys_swapoff+0x46d/0x490 do_syscall_64+0x5a/0x190 entry_SYSCALL_64_after_hwframe+0x49/0xbe irq event stamp: 4466 hardirqs last enabled at (4465): __free_pages_ok+0x1e3/0x490 hardirqs last disabled at (4466): trace_hardirqs_off_thunk+0x1a/0x1c softirqs last enabled at (3420): __do_softirq+0x333/0x446 softirqs last disabled at (3407): irq_exit+0xd1/0xe0 Link: http://lkml.kernel.org/r/20181127055429.251614-3-minchan@kernel.org Signed-off-by: Minchan Kim Reviewed-by: Sergey Senozhatsky Reviewed-by: Joey Pabalinas Cc: [4.14+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- drivers/block/zram/zram_drv.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -382,8 +382,10 @@ static ssize_t backing_dev_store(struct 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);