From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 24B591CC8A7; Thu, 2 Jan 2025 23:25:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735860338; cv=none; b=h94Q1moH/xna+D1QbQWUn5opdPkwr3aQMRo0FLbaTPY03J+9AS6PIadzKpJuxUbjn1UECx2I/grt3qpn5J1QXjmWm45QaLaBBB0AZMSG7YljOU9bjkYJdo/nwdZWoWE1K2Gi0qaQElAVtfN+2Xa/Mthc7CwFk76ZxtGG/j2LYuQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735860338; c=relaxed/simple; bh=mX7FJpx4118ooaZkB/8HWQSJOOPye7uU6pAwUySw0ws=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=oEScSvVm4y8ZxNOgvVg5ZgiRGKS2guzx3qTJQtavhNLodrXQLLsKVktTwNZCexajalQOOyjB7aBxg8ZcGzbW817mEgGvUICJIdILjKN+YqpjRJEaarvgpIkuXJHg+G+26hdA0GwdrYvtTcYtdJTDGqcjzXbumIWx652ruL5tWN4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=uttgSEl7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="uttgSEl7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F0325C4CED7; Thu, 2 Jan 2025 23:25:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1735860338; bh=mX7FJpx4118ooaZkB/8HWQSJOOPye7uU6pAwUySw0ws=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=uttgSEl7WvTBTYvBOym5lnIvpwq8txSb23qqFP27KtrOUAanmgGQ004iJ6FfHDtiM 0HD1sZbdxJ1CjrVZJAk3hX0kmJpVSYUJWKvUlgIh/pIzXsdOLEnXSj0XocPnFxSLFC 2w2ZnazfF61HEAyhIaGtJUglqSUU/5ytT9jA9FbMWljXfSX/r2Sme53K8Gm25wGDKZ p+PhosAjMCdJ6mi9wzLUSEBkMVFqhDm/Syc5n7SHg0DCE77CQBEDBWfEmCA8zZB0GT SqWGh/G3pPbtNNerhevUszf9B/G3jHro6J6GusdFeJxkFKp1fSRlObgBRUCknxnnsy rAnCT/TwJzsog== Date: Thu, 2 Jan 2025 15:25:36 -0800 From: "Darrick J. Wong" To: Andrew Morton Cc: Marco Nelissen , "Matthew Wilcox (Oracle)" , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org Subject: Re: [PATCH] filemap: avoid truncating 64-bit offset to 32 bits Message-ID: <20250102232536.GW6174@frogsfrogsfrogs> References: <20250102190540.1356838-1-marco.nelissen@gmail.com> <20250102141015.bc8ef069a91cfd9664538494@linux-foundation.org> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250102141015.bc8ef069a91cfd9664538494@linux-foundation.org> On Thu, Jan 02, 2025 at 02:10:15PM -0800, Andrew Morton wrote: > On Thu, 2 Jan 2025 11:04:11 -0800 Marco Nelissen wrote: > > > on 32-bit kernels, folio_seek_hole_data() was inadvertently truncating a > > 64-bit value to 32 bits, leading to a possible infinite loop when writing > > to an xfs filesystem. > > > > ... > > > > +++ b/mm/filemap.c > > @@ -3005,7 +3005,7 @@ static inline loff_t folio_seek_hole_data(struct xa_state *xas, > > if (ops->is_partially_uptodate(folio, offset, bsz) == > > seek_data) > > break; > > - start = (start + bsz) & ~(bsz - 1); > > + start = (start + bsz) & ~((u64)bsz - 1); > > offset += bsz; > > } while (offset < folio_size(folio)); > > unlock: > > Thanks. I'll add > > Fixes: 54fa39ac2e00b ("iomap: use mapping_seek_hole_data") > Cc: > > The > > offset = offset_in_folio(folio, start) & ~(bsz - 1); > > a few lines earlier is worrisome. I wonder if we should simply make > `bsz' and `offset' have type u64 and sleep well at night. I think that callsite is ok because offset_in_folio() should never return a value larger than 2^31 ... right? IOWs, only the second case needs casting because @start is loff_t. --D