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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 3FA2CC43142 for ; Sun, 24 Jun 2018 15:42:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EA21D25064 for ; Sun, 24 Jun 2018 15:42:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EA21D25064 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.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 S1756040AbeFXPmB (ORCPT ); Sun, 24 Jun 2018 11:42:01 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:60032 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755680AbeFXPl6 (ORCPT ); Sun, 24 Jun 2018 11:41:58 -0400 Received: from localhost (li1825-44.members.linode.com [172.104.248.44]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 4BE4D49F; Sun, 24 Jun 2018 15:41:56 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Omar Sandoval , Su Yue , David Sterba Subject: [PATCH 4.17 25/70] Btrfs: fix memory and mount leak in btrfs_ioctl_rm_dev_v2() Date: Sun, 24 Jun 2018 23:22:17 +0800 Message-Id: <20180624142742.028067538@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180624142740.481662434@linuxfoundation.org> References: <20180624142740.481662434@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Omar Sandoval commit fd4e994bd1f9dc9628e168a7f619bf69f6984635 upstream. If we have invalid flags set, when we error out we must drop our writer counter and free the buffer we allocated for the arguments. This bug is trivially reproduced with the following program on 4.7+: #include #include #include #include #include #include #include #include #include #include int main(int argc, char **argv) { struct btrfs_ioctl_vol_args_v2 vol_args = { .flags = UINT64_MAX, }; int ret; int fd; if (argc != 2) { fprintf(stderr, "usage: %s PATH\n", argv[0]); return EXIT_FAILURE; } fd = open(argv[1], O_WRONLY); if (fd == -1) { perror("open"); return EXIT_FAILURE; } ret = ioctl(fd, BTRFS_IOC_RM_DEV_V2, &vol_args); if (ret == -1) perror("ioctl"); close(fd); return EXIT_SUCCESS; } When unmounting the filesystem, we'll hit the WARN_ON(mnt_get_writers(mnt)) in cleanup_mnt() and also may prevent the filesystem to be remounted read-only as the writer count will stay lifted. Fixes: 6b526ed70cf1 ("btrfs: introduce device delete by devid") CC: stable@vger.kernel.org # 4.9+ Signed-off-by: Omar Sandoval Reviewed-by: Su Yue Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/ioctl.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -2654,8 +2654,10 @@ static long btrfs_ioctl_rm_dev_v2(struct } /* Check for compatibility reject unknown flags */ - if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED) - return -EOPNOTSUPP; + if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED) { + ret = -EOPNOTSUPP; + goto out; + } if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) { ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;