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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,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 0F1F1C33C9B for ; Tue, 7 Jan 2020 21:14:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CD5002080A for ; Tue, 7 Jan 2020 21:14:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578431679; bh=iBoHMJDZnbO3kqXZFkUczZBgYWQj2tfUMH+07frX/jU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=oce9Idz21qecYroF/V+PYrGNOu1LZhm+4T37WERGKNgIaHKlDPBXKF+tg9L3PZRKZ MondvJMwlH7IlUoQuYQXBkUbCdQagywWY/wMmtyKqR6pxTTH6xbUdhy2XleUzPIhQd iJK/2B0K++by8oSkGFt7rXDL98Q9140nsBNA0zIo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729770AbgAGVOi (ORCPT ); Tue, 7 Jan 2020 16:14:38 -0500 Received: from mail.kernel.org ([198.145.29.99]:34250 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729786AbgAGVJK (ORCPT ); Tue, 7 Jan 2020 16:09:10 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.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 8B6B02077B; Tue, 7 Jan 2020 21:09:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578431350; bh=iBoHMJDZnbO3kqXZFkUczZBgYWQj2tfUMH+07frX/jU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SsNqJFwGkWvSiWhXQT5nzyhR+9j22Kma2fb+q5nOq6Fk9j2535hMKCXVfSg8WiFCc rvkJ2WFvdxQo3jO6E9mkUmrvJ006rZLPqzMN+R1/es3TmGcesXRhZlNOh2uC6+D5Jb tmSdQ/vAVbTybZFxDfjMtuFj2gFeHwUFvd/hHnEo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+c732f8644185de340492@syzkaller.appspotmail.com, Brian Foster , "Darrick J. Wong" , Sasha Levin Subject: [PATCH 4.14 20/74] xfs: fix mount failure crash on invalid iclog memory access Date: Tue, 7 Jan 2020 21:54:45 +0100 Message-Id: <20200107205149.039516312@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200107205135.369001641@linuxfoundation.org> References: <20200107205135.369001641@linuxfoundation.org> User-Agent: quilt/0.66 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 From: Brian Foster [ Upstream commit 798a9cada4694ca8d970259f216cec47e675bfd5 ] syzbot (via KASAN) reports a use-after-free in the error path of xlog_alloc_log(). Specifically, the iclog freeing loop doesn't handle the case of a fully initialized ->l_iclog linked list. Instead, it assumes that the list is partially constructed and NULL terminated. This bug manifested because there was no possible error scenario after iclog list setup when the original code was added. Subsequent code and associated error conditions were added some time later, while the original error handling code was never updated. Fix up the error loop to terminate either on a NULL iclog or reaching the end of the list. Reported-by: syzbot+c732f8644185de340492@syzkaller.appspotmail.com Signed-off-by: Brian Foster Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Signed-off-by: Sasha Levin --- fs/xfs/xfs_log.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index dc95a49d62e7..4e768e606998 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -1539,6 +1539,8 @@ xlog_alloc_log( if (iclog->ic_bp) xfs_buf_free(iclog->ic_bp); kmem_free(iclog); + if (prev_iclog == log->l_iclog) + break; } spinlock_destroy(&log->l_icloglock); xfs_buf_free(log->l_xbuf); -- 2.20.1