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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A0C92C77B71 for ; Fri, 21 Apr 2023 15:35:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232834AbjDUPfX (ORCPT ); Fri, 21 Apr 2023 11:35:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34008 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232323AbjDUPfW (ORCPT ); Fri, 21 Apr 2023 11:35:22 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7CBB17DA3 for ; Fri, 21 Apr 2023 08:35:18 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D95446188A for ; Fri, 21 Apr 2023 15:35:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 44921C433D2; Fri, 21 Apr 2023 15:35:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1682091317; bh=JrdtzbUnhsxx2/nvCIAED443EvNI0LUXSxQaqOTYW/k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=f1BuDfVjBDccoYCQzdhbT2ZuVYo6Tu8gIVy4dJrQ6RgJvbRsoWb8g5TaMnY21+mVA VLLi40dbkeGX+3C3+zhTRW7sQcoh+b60upGitZrch9nSHSKPtU1M42AGUy9Ho00y7E 136dIRNoU4L32zJ5V27o78V/DnEOnMhHXiB5wXe7JfPwOaPOudWY9GNY82jo+3WRBq O6Ivj8M+4on+MJsDkXaYh8JrRpVEqqDS+esR7nJL65M2JcTNXUNXzCYg8X75OatJZk SzM+HPA9jzlt04NDfOTmMfxUbkkU1tkHVSLVHCa0/cU4OXfak9H+THhu57N+SZsGt2 qwUJ2xgkdjiaw== Date: Fri, 21 Apr 2023 08:35:16 -0700 From: "Darrick J. Wong" To: Chandan Babu R Cc: linux-xfs@vger.kernel.org, amir73il@gmail.com, leah.rumancik@gmail.com Subject: Re: [PATCH 5.4 CANDIDATE] xfs: fix forkoff miscalculation related to XFS_LITINO(mp) Message-ID: <20230421153516.GJ360889@frogsfrogsfrogs> References: <20230421030619.62047-1-chandan.babu@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230421030619.62047-1-chandan.babu@oracle.com> Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Fri, Apr 21, 2023 at 08:36:19AM +0530, Chandan Babu R wrote: > From: Gao Xiang > > commit ada49d64fb3538144192181db05de17e2ffc3551 upstream. > > Currently, commit e9e2eae89ddb dropped a (int) decoration from > XFS_LITINO(mp), and since sizeof() expression is also involved, > the result of XFS_LITINO(mp) is simply as the size_t type > (commonly unsigned long). > > Considering the expression in xfs_attr_shortform_bytesfit(): > offset = (XFS_LITINO(mp) - bytes) >> 3; > let "bytes" be (int)340, and > "XFS_LITINO(mp)" be (unsigned long)336. > > on 64-bit platform, the expression is > offset = ((unsigned long)336 - (int)340) >> 3 = > (int)(0xfffffffffffffffcUL >> 3) = -1 > > but on 32-bit platform, the expression is > offset = ((unsigned long)336 - (int)340) >> 3 = > (int)(0xfffffffcUL >> 3) = 0x1fffffff > instead. > > so offset becomes a large positive number on 32-bit platform, and > cause xfs_attr_shortform_bytesfit() returns maxforkoff rather than 0. > > Therefore, one result is > "ASSERT(new_size <= XFS_IFORK_SIZE(ip, whichfork));" > > assertion failure in xfs_idata_realloc(), which was also the root > cause of the original bugreport from Dennis, see: > https://bugzilla.redhat.com/show_bug.cgi?id=1894177 > > And it can also be manually triggered with the following commands: > $ touch a; > $ setfattr -n user.0 -v "`seq 0 80`" a; > $ setfattr -n user.1 -v "`seq 0 80`" a > > on 32-bit platform. > > Fix the case in xfs_attr_shortform_bytesfit() by bailing out > "XFS_LITINO(mp) < bytes" in advance suggested by Eric and a misleading > comment together with this bugfix suggested by Darrick. It seems the > other users of XFS_LITINO(mp) are not impacted. > > Fixes: e9e2eae89ddb ("xfs: only check the superblock version for dinode size calculation") > Cc: # 5.7+ > Reported-and-tested-by: Dennis Gilmore > Reviewed-by: Christoph Hellwig > Signed-off-by: Gao Xiang > Reviewed-by: Darrick J. Wong > Signed-off-by: Darrick J. Wong > Signed-off-by: Chandan Babu R Looks good to me, Acked-by: Darrick J. Wong --D > --- > > Hi Darrick, > > I had missed this commit when backporting fixes from 5.11 and 5.12. I > have executed 10 iterations of fstests via kdevops and did not notice > any new regressions. > > Please ack this patch. > > fs/xfs/libxfs/xfs_attr_leaf.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c b/fs/xfs/libxfs/xfs_attr_leaf.c > index f5b16120c64d..2b74b6e9a354 100644 > --- a/fs/xfs/libxfs/xfs_attr_leaf.c > +++ b/fs/xfs/libxfs/xfs_attr_leaf.c > @@ -435,7 +435,7 @@ xfs_attr_copy_value( > *========================================================================*/ > > /* > - * Query whether the requested number of additional bytes of extended > + * Query whether the total requested number of attr fork bytes of extended > * attribute space will be able to fit inline. > * > * Returns zero if not, else the di_forkoff fork offset to be used in the > @@ -455,6 +455,12 @@ xfs_attr_shortform_bytesfit( > int maxforkoff; > int offset; > > + /* > + * Check if the new size could fit at all first: > + */ > + if (bytes > XFS_LITINO(mp)) > + return 0; > + > /* rounded down */ > offset = (XFS_LITINO(mp) - bytes) >> 3; > > -- > 2.39.1 >