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 720B1325483 for ; Mon, 24 Nov 2025 21:06:28 +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=1764018388; cv=none; b=KO8i3XwskNnpjJmlzjRX2YWsVwb4Al9si5JPV9ykZhmVHhboLw1y/JeB6cZU2q+2f1iRIC0a/EVps/cAcfjQuuoA3VtWnaPXH4h/hA3XjLbRqW+tOauLzO8RizjCa3WSM7JtRs/QzoPcPBujnpQfKISPZwFPwRyJxgVK5xgKWW4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764018388; c=relaxed/simple; bh=5ZpbdBOEme5Ef7yD8vxuIFpt/rRhKUZ4HY8PVU4Fpo8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=mW2qFDseyhytgimD1jTRqHRJ7dbnVBpYvF501Eeefw9OmmplqQl3gJBjyQqkn/2ywhRmYMyu36ISx7qP9C0odRTUB1z6kEo5ubIuSpJ5YSeMxemeugF7KjrI/2ERLx9vDv5LTzCAv+XjX8ekZAl9kCj8AT2Y4t14QzMaieVBVws= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=MneGRE5Y; 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="MneGRE5Y" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 44062C4CEF1; Mon, 24 Nov 2025 21:06:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764018388; bh=5ZpbdBOEme5Ef7yD8vxuIFpt/rRhKUZ4HY8PVU4Fpo8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=MneGRE5YfqloYRWYJ2L43A3dMy6bQMkj7pqpMXSmicTWkMJ5kfBym8XFudRcYX1TZ dfrifPk9s8kNFw5Gz+tHGOuonOz6/ok9phUhrrW4aOY9LlVHuHTkSRSxH9HHWVDUvy 9tBZPzDEnDB6d3cw3eCiCnxe67B43BAZK+x18CiXY+ZojbNPy6IMp5sWISMjryaT1Y i8SqeV+0wTyFb8ZLi5IMMmwCdScm7Yr7qFPSC6LjomBpY7Tyw3YY5ViZ1RtS42UwEC Rk9nmqQVVWF95lepBqNkbk0GAwPSgELQmPrUUxbH2ixDwrJbbn1lfxAo6L4L2nL8xR yivTaa1MknR8w== Date: Mon, 24 Nov 2025 13:06:27 -0800 From: Kees Cook To: "Matthew Wilcox (Oracle)" Cc: Vlastimil Babka , Andrew Morton , Christoph Lameter , David Rientjes , Roman Gushchin , Harry Yoo , linux-mm@kvack.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org Subject: Re: [PATCH v4 13/16] usercopy: Remove folio references from check_heap_object() Message-ID: <202511241306.525D3248@keescook> References: <20251113000932.1589073-1-willy@infradead.org> <20251113000932.1589073-14-willy@infradead.org> Precedence: bulk X-Mailing-List: linux-hardening@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: <20251113000932.1589073-14-willy@infradead.org> On Thu, Nov 13, 2025 at 12:09:27AM +0000, Matthew Wilcox (Oracle) wrote: > Use page_slab() instead of virt_to_folio() followed by folio_slab(). > We do end up calling compound_head() twice for non-slab copies, but that > will not be a problem once we allocate memdescs separately. > > Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Kees Cook -- Kees Cook