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 D18F3C43217 for ; Tue, 12 Apr 2022 07:18:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351544AbiDLHUi (ORCPT ); Tue, 12 Apr 2022 03:20:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57352 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351777AbiDLHM4 (ORCPT ); Tue, 12 Apr 2022 03:12:56 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 72EB7E55; Mon, 11 Apr 2022 23:52:31 -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 0FF0D6149D; Tue, 12 Apr 2022 06:52:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2004DC385A6; Tue, 12 Apr 2022 06:52:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649746350; bh=FCi1zb4GbbR20Yat8e/QaOYMtXuyUyOOWTtWNybjKNE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xdiPfj9+JfMjOutM6L8E+cJwvRqdkSZVixdBes+lycCx/E7spR3fTemcto6arxBV3 c0lOzTHmS3LPYn90p0lP5DBwpnELiYCjGSRoP7MJpgo3pnZvco9mAWDwZxcUDOUUuj ZUNGL/cGmELXcRG/b+tyQn4dQ+511QnC7irKE+us= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexei Starovoitov , Jakub Sitnicki Subject: [PATCH 5.15 251/277] bpf: Make remote_port field in struct bpf_sk_lookup 16-bit wide Date: Tue, 12 Apr 2022 08:30:54 +0200 Message-Id: <20220412062949.306806264@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220412062942.022903016@linuxfoundation.org> References: <20220412062942.022903016@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jakub Sitnicki commit 9a69e2b385f443f244a7e8b8bcafe5ccfb0866b4 upstream. remote_port is another case of a BPF context field documented as a 32-bit value in network byte order for which the BPF context access converter generates a load of a zero-padded 16-bit integer in network byte order. First such case was dst_port in bpf_sock which got addressed in commit 4421a582718a ("bpf: Make dst_port field in struct bpf_sock 16-bit wide"). Loading 4-bytes from the remote_port offset and converting the value with bpf_ntohl() leads to surprising results, as the expected value is shifted by 16 bits. Reduce the confusion by splitting the field in two - a 16-bit field holding a big-endian integer, and a 16-bit zero-padding anonymous field that follows it. Suggested-by: Alexei Starovoitov Signed-off-by: Jakub Sitnicki Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20220209184333.654927-2-jakub@cloudflare.com Signed-off-by: Greg Kroah-Hartman --- include/uapi/linux/bpf.h | 3 ++- net/bpf/test_run.c | 4 ++-- net/core/filter.c | 3 ++- 3 files changed, 6 insertions(+), 4 deletions(-) --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -6223,7 +6223,8 @@ struct bpf_sk_lookup { __u32 protocol; /* IP protocol (IPPROTO_TCP, IPPROTO_UDP) */ __u32 remote_ip4; /* Network byte order */ __u32 remote_ip6[4]; /* Network byte order */ - __u32 remote_port; /* Network byte order */ + __be16 remote_port; /* Network byte order */ + __u16 :16; /* Zero padding */ __u32 local_ip4; /* Network byte order */ __u32 local_ip6[4]; /* Network byte order */ __u32 local_port; /* Host byte order */ --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -954,7 +954,7 @@ int bpf_prog_test_run_sk_lookup(struct b if (!range_is_zero(user_ctx, offsetofend(typeof(*user_ctx), local_port), sizeof(*user_ctx))) goto out; - if (user_ctx->local_port > U16_MAX || user_ctx->remote_port > U16_MAX) { + if (user_ctx->local_port > U16_MAX) { ret = -ERANGE; goto out; } @@ -962,7 +962,7 @@ int bpf_prog_test_run_sk_lookup(struct b ctx.family = (u16)user_ctx->family; ctx.protocol = (u16)user_ctx->protocol; ctx.dport = (u16)user_ctx->local_port; - ctx.sport = (__force __be16)user_ctx->remote_port; + ctx.sport = user_ctx->remote_port; switch (ctx.family) { case AF_INET: --- a/net/core/filter.c +++ b/net/core/filter.c @@ -10540,7 +10540,8 @@ static bool sk_lookup_is_valid_access(in case bpf_ctx_range(struct bpf_sk_lookup, local_ip4): case bpf_ctx_range_till(struct bpf_sk_lookup, remote_ip6[0], remote_ip6[3]): case bpf_ctx_range_till(struct bpf_sk_lookup, local_ip6[0], local_ip6[3]): - case bpf_ctx_range(struct bpf_sk_lookup, remote_port): + case offsetof(struct bpf_sk_lookup, remote_port) ... + offsetof(struct bpf_sk_lookup, local_ip4) - 1: case bpf_ctx_range(struct bpf_sk_lookup, local_port): bpf_ctx_record_field_size(info, sizeof(__u32)); return bpf_ctx_narrow_access_ok(off, size, sizeof(__u32));