From patchwork Wed Aug 19 05:19:45 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 1347442 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; secure) header.d=infradead.org header.i=@infradead.org header.a=rsa-sha256 header.s=casper.20170209 header.b=ElW0HqjJ; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4BWbh35Z5jz9sPf for ; Wed, 19 Aug 2020 15:20:03 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726482AbgHSFT4 (ORCPT ); Wed, 19 Aug 2020 01:19:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49724 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725803AbgHSFT4 (ORCPT ); Wed, 19 Aug 2020 01:19:56 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6C507C061389; Tue, 18 Aug 2020 22:19:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:In-Reply-To:References; bh=0xtII03aY1sMWDNlNgJtnoIL3vhRsrk36uree1jHzx4=; b=ElW0HqjJ7mt+amGMbev8PXlKvD R/VRen2NGsysJ+N1f6hWPh0lF5skZHdNhgphqwtEJUrFYti1UOGHcKtn2VKTFugFqYwyWv06i5DfA qTROS7b4Wlp5OoXtNUQAuS/ZGZK+mOdqYgMy1y1KLMXsFtO1CAXmkZpFshVME8GfdLQpgiXrWjyLG 84NGNCq4x0ZESkm5LkYdhAOTRLjYc8IqTAXLDF/bA+bTL7p9i/v0mWXpBshv8DMcbxEKw+23TaSdx /GW+2xPb8VrirmzOBy+zXh2ydoKX1UAWJa4cBX9LrNPG5pYQGF4GZ+cJP+cc0/GaLibcODjUXonHm lvonc9tQ==; Received: from [2001:4bb8:198:f3b2:86b6:2277:f429:37a1] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1k8GVn-0002aC-4V; Wed, 19 Aug 2020 05:19:47 +0000 From: Christoph Hellwig To: davem@davemloft.net, kuba@kernel.org Cc: colyli@suse.de, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] net: bypass ->sendpage for slab pages Date: Wed, 19 Aug 2020 07:19:45 +0200 Message-Id: <20200819051945.1797088-1-hch@lst.de> X-Mailer: git-send-email 2.28.0 MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Sending Slab or tail pages into ->sendpage will cause really strange delayed oops. Prevent it right in the networking code instead of requiring drivers to guess the exact conditions where sendpage works. Based on a patch from Coly Li . Signed-off-by: Christoph Hellwig --- net/socket.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/net/socket.c b/net/socket.c index dbbe8ea7d395da..b4e65688915fe3 100644 --- a/net/socket.c +++ b/net/socket.c @@ -3638,7 +3638,11 @@ EXPORT_SYMBOL(kernel_getpeername); int kernel_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags) { - if (sock->ops->sendpage) + /* sendpage does manipulates the refcount of the sent in page, which + * does not work for Slab pages, or for tails of non-__GFP_COMP + * high order pages. + */ + if (sock->ops->sendpage && !PageSlab(page) && page_count(page) > 0) return sock->ops->sendpage(sock, page, offset, size, flags); return sock_no_sendpage(sock, page, offset, size, flags);