From nobody Wed Feb 11 12:35:39 2026 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 2E66FC7618D for ; Thu, 6 Apr 2023 09:46:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236788AbjDFJqV (ORCPT ); Thu, 6 Apr 2023 05:46:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51956 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236723AbjDFJow (ORCPT ); Thu, 6 Apr 2023 05:44:52 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C657383F6 for ; Thu, 6 Apr 2023 02:43:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1680774217; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Lhpi7afnUSYBVmFcNV33/AfpfwJkESufDM5kupMXc5M=; b=C/KEt8yiz8eyWTOqZ1H9mEQeQ5DdGfiyGURpwBjnnyZqacE4V1bSZiKHQqECqyOMLPiMMM EdCVb7ydz5JOYlqM5AFO1rMQVDMcoFJdKflQYc0Yk+pJa7u+X9ZwwLRoP9/pwzJM40rAwu kaG3lF2LqcRfqhgRUI6XnN4tWeriO2Q= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-387-ZCLBzN6RN_yR-HE_tGR4oA-1; Thu, 06 Apr 2023 05:43:34 -0400 X-MC-Unique: ZCLBzN6RN_yR-HE_tGR4oA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id D9DE93C0ED40; Thu, 6 Apr 2023 09:43:33 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.33.36.18]) by smtp.corp.redhat.com (Postfix) with ESMTP id C6DC0202701F; Thu, 6 Apr 2023 09:43:31 +0000 (UTC) From: David Howells To: netdev@vger.kernel.org Cc: David Howells , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Willem de Bruijn , Matthew Wilcox , Al Viro , Christoph Hellwig , Jens Axboe , Jeff Layton , Christian Brauner , Chuck Lever III , Linus Torvalds , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, David Ahern Subject: [PATCH net-next v5 14/19] ip, udp: Make sendmsg(MSG_SPLICE_PAGES) copy unspliceable data Date: Thu, 6 Apr 2023 10:42:40 +0100 Message-Id: <20230406094245.3633290-15-dhowells@redhat.com> In-Reply-To: <20230406094245.3633290-1-dhowells@redhat.com> References: <20230406094245.3633290-1-dhowells@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" If sendmsg() with MSG_SPLICE_PAGES encounters a page that shouldn't be spliced - a slab page, for instance, or one with a zero count - make __ip_append_data() copy it. Signed-off-by: David Howells cc: Willem de Bruijn cc: David Ahern cc: "David S. Miller" cc: Eric Dumazet cc: Jakub Kicinski cc: Paolo Abeni cc: Jens Axboe cc: Matthew Wilcox cc: netdev@vger.kernel.org --- net/ipv4/ip_output.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index c6c318eb3d37..48db7bf475df 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -967,13 +967,32 @@ static int __ip_splice_pages(struct sock *sk, struct = sk_buff *skb, struct page *page =3D NULL, **pages =3D &page; ssize_t copy =3D *pcopy; size_t off; + bool put =3D false; int err; =20 copy =3D iov_iter_extract_pages(&msg->msg_iter, &pages, copy, 1, 0, &off); if (copy <=3D 0) return copy ?: -EIO; =20 + if (!sendpage_ok(page)) { + const void *p =3D kmap_local_page(page); + void *q; + + q =3D page_frag_memdup(NULL, p + off, copy, + sk->sk_allocation, ULONG_MAX); + kunmap_local(p); + if (!q) { + iov_iter_revert(&msg->msg_iter, copy); + return -ENOMEM; + } + page =3D virt_to_page(q); + off =3D offset_in_page(q); + put =3D true; + } + err =3D skb_append_pagefrags(skb, page, off, copy); + if (put) + put_page(page); if (err < 0) { iov_iter_revert(&msg->msg_iter, copy); return err;