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=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 3B473C33C9E for ; Sat, 11 Jan 2020 09:54:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 039222072E for ; Sat, 11 Jan 2020 09:54:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578736479; bh=CW+8YHjb911IXQD++FpPnPErWmULIcsG8GPVMa5/gdU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=R3orZLKVreYj3LQOjavLYZ5ecpXCN9bjBubkxZ18sAwgV6b7/hVVVirmerVDQH5+O j8SqJxoPH63a6c33I7uNa2G5YkZSt373/RBLmKHe1VSrcQyq8p2f34H36yKruAryyt UIZCbE2NnjpYLHjRuagfSkgjbdtaGQBz+qwNwgkU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728846AbgAKJyh (ORCPT ); Sat, 11 Jan 2020 04:54:37 -0500 Received: from mail.kernel.org ([198.145.29.99]:43304 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728807AbgAKJyg (ORCPT ); Sat, 11 Jan 2020 04:54:36 -0500 Received: from localhost (unknown [62.119.166.9]) (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 032512072E; Sat, 11 Jan 2020 09:54:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578736475; bh=CW+8YHjb911IXQD++FpPnPErWmULIcsG8GPVMa5/gdU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=J5sstdRlfieUO8ZDKO2qRW7vYOAk6Xtu/wDMZFAwJms5iCvhYvZAlAmRIP5qbTn6L vSh7e5uiNATKVf/3ZLh/Tp2mlCy7UkyHFN0+g1JZEH5g6tYjrMmm9Vw41NtEUcEcFy /0MnyIxpLWX4vJ9njkYKSsedYm6I2OAYfAXhYGDk= 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 4.4 12/59] xfs: fix mount failure crash on invalid iclog memory access Date: Sat, 11 Jan 2020 10:49:21 +0100 Message-Id: <20200111094840.323120975@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200111094835.417654274@linuxfoundation.org> References: <20200111094835.417654274@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 73b725f965eb..065aa4752607 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -1503,6 +1503,8 @@ 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