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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 4D3BAC43603 for ; Mon, 16 Dec 2019 17:56:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 25F7D21739 for ; Mon, 16 Dec 2019 17:56:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576518968; bh=z3Kj59tElYDFczXrLzBvFGf3Lq0FVEcXhM0H7/niF5w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=hDxBq+P+8dxwz4vk/roAPTIICfFiDIOkuswiAUa0eqsNLXSfrrANjZOOvFrB4Cvu0 B2bUn6an22ZbuutRxM0cRIlegpzidtDBAboT7JLPTvjOWFPk+gj4iGzjafF3Q0lmZ0 cLJ8elh+GmBWkjBy+kv4cuARmwf1oad2ms0J7PnI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728154AbfLPR4H (ORCPT ); Mon, 16 Dec 2019 12:56:07 -0500 Received: from mail.kernel.org ([198.145.29.99]:53824 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728152AbfLPR4E (ORCPT ); Mon, 16 Dec 2019 12:56:04 -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 90D36205ED; Mon, 16 Dec 2019 17:56:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576518964; bh=z3Kj59tElYDFczXrLzBvFGf3Lq0FVEcXhM0H7/niF5w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=n5REI/HtGV94qLxsBnJg5NaS6jZnHtIsLwWtQqoLlnL0dA08bntKU5rh3xJX5h4O+ gB4yWCDexksL6moDzMh2XNCZdABGXiqnLKm4BEpg55oU1q0WrKw/dSutfl6iHqFFf1 bAsfxhVB+y/8BR8UPtsDiG6J7rr2tbqJxawg/p3A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Theodore Tso , Jan Kara Subject: [PATCH 4.14 138/267] jbd2: Fix possible overflow in jbd2_log_space_left() Date: Mon, 16 Dec 2019 18:47:44 +0100 Message-Id: <20191216174909.393995412@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191216174848.701533383@linuxfoundation.org> References: <20191216174848.701533383@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: Jan Kara commit add3efdd78b8a0478ce423bb9d4df6bd95e8b335 upstream. When number of free space in the journal is very low, the arithmetic in jbd2_log_space_left() could underflow resulting in very high number of free blocks and thus triggering assertion failure in transaction commit code complaining there's not enough space in the journal: J_ASSERT(journal->j_free > 1); Properly check for the low number of free blocks. CC: stable@vger.kernel.org Reviewed-by: Theodore Ts'o Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20191105164437.32602-1-jack@suse.cz Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- include/linux/jbd2.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/include/linux/jbd2.h +++ b/include/linux/jbd2.h @@ -1584,7 +1584,7 @@ static inline int jbd2_space_needed(jour static inline unsigned long jbd2_log_space_left(journal_t *journal) { /* Allow for rounding errors */ - unsigned long free = journal->j_free - 32; + long free = journal->j_free - 32; if (journal->j_committing_transaction) { unsigned long committing = atomic_read(&journal-> @@ -1593,7 +1593,7 @@ static inline unsigned long jbd2_log_spa /* Transaction + control blocks */ free -= committing + (committing >> JBD2_CONTROL_BLOCKS_SHIFT); } - return free; + return max_t(long, free, 0); } /*