From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-180.mta0.migadu.com (out-180.mta0.migadu.com [91.218.175.180]) (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 543A527B32B for ; Mon, 9 Mar 2026 03:08:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.180 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773025683; cv=none; b=kgjh46zLLOLNiI1ON7UY6E84YakRABpuG3gS23uNHQ4MCe7VYu9zDU9G+j9uGIiWRzjd6EHHrR9r0tLZUaI1t57NUrIvr2yB5g4YLjLUTaZThTuLWUJ4H+p5cHWkv6gO7dnLwXQvmc7XldbWYXIBKMpg35YGipK2V45OuT7cCMY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773025683; c=relaxed/simple; bh=01vmzJFYdIKTUpjD4r4bbmdcSux/e/nxggybk6R9JZE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NbXcieadQAkI39osB9jJwp+sYUeHRugYqHC3vnas88/2TQYblY3pvQkvEAqD7sdsZO/tBt5+wUemqUKGIBNMArF66vam/ZlX2q4m9Hi6hZUKa/Xf13MeQuDWmjvarbKfJNC4yjcbqqwRK9jfyL3PAvT8W7DL/G0JS5DQg6aKFAM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=fwxcV5A+; arc=none smtp.client-ip=91.218.175.180 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="fwxcV5A+" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1773025680; 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=I5X6ee4TNtT9Dw1K/34UFfmHdjfuqBZpbf/e+JmlsmY=; b=fwxcV5A+nMogDKR+OOARgoNiwv1kRAdncFf8N7CmQWx44F98Vn9Xp4BqCjoe7zzKb6wZZJ CuG/j2btxmGYDHtpDodci+aV1ISutFEBEx0tN3vdPtWDc8Ritg+EtIetBaGNaA2NfJ2CJf PCYlVl5Xce5nOOtogt9H/WrD3EY0aaw= From: Jiayuan Chen To: netdev@vger.kernel.org Cc: razor@blackwall.org, jiayuan.chen@shopee.com, jiayuan.chen@linux.dev, Jay Vosburgh , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , Stanislav Fomichev , Andrii Nakryiko , Eduard Zingerman , Martin KaFai Lau , Song Liu , Yonghong Song , KP Singh , Hao Luo , Jiri Olsa , Shuah Khan , Sebastian Andrzej Siewior , Clark Williams , Steven Rostedt , Jussi Maki , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-rt-devel@lists.linux.dev Subject: [PATCH net v5 2/2] selftests/bpf: add test for xdp_master_redirect with bond not up Date: Mon, 9 Mar 2026 11:06:59 +0800 Message-ID: <20260309030702.128520-3-jiayuan.chen@linux.dev> In-Reply-To: <20260309030702.128520-1-jiayuan.chen@linux.dev> References: <20260309030702.128520-1-jiayuan.chen@linux.dev> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT From: Jiayuan Chen Add a selftest that reproduces the null-ptr-deref in bond_rr_gen_slave_id() when XDP redirect targets a bond device in round-robin mode that was never brought up. The test verifies the fix by ensuring no crash occurs. Test setup: - bond0: active-backup mode, UP, with native XDP (enables bpf_master_redirect_enabled_key globally) - bond1: round-robin mode, never UP - veth1: slave of bond1, with generic XDP (XDP_TX) - BPF_PROG_TEST_RUN with live frames triggers the redirect path Signed-off-by: Jiayuan Chen --- .../selftests/bpf/prog_tests/xdp_bonding.c | 101 +++++++++++++++++- 1 file changed, 99 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_bonding.c b/tools/testing/selftests/bpf/prog_tests/xdp_bonding.c index e8ea26464349..0d4ec1e5b401 100644 --- a/tools/testing/selftests/bpf/prog_tests/xdp_bonding.c +++ b/tools/testing/selftests/bpf/prog_tests/xdp_bonding.c @@ -191,13 +191,18 @@ static int bonding_setup(struct skeletons *skeletons, int mode, int xmit_policy, return -1; } -static void bonding_cleanup(struct skeletons *skeletons) +static void link_cleanup(struct skeletons *skeletons) { - restore_root_netns(); while (skeletons->nlinks) { skeletons->nlinks--; bpf_link__destroy(skeletons->links[skeletons->nlinks]); } +} + +static void bonding_cleanup(struct skeletons *skeletons) +{ + restore_root_netns(); + link_cleanup(skeletons); ASSERT_OK(system("ip link delete bond1"), "delete bond1"); ASSERT_OK(system("ip link delete veth1_1"), "delete veth1_1"); ASSERT_OK(system("ip link delete veth1_2"), "delete veth1_2"); @@ -493,6 +498,95 @@ static void test_xdp_bonding_nested(struct skeletons *skeletons) system("ip link del bond_nest2"); } +/* + * Test that XDP redirect via xdp_master_redirect() does not crash when + * the bond master device is not up. When bond is in round-robin mode but + * never opened, rr_tx_counter is NULL. + */ +static void test_xdp_bonding_redirect_no_up(struct skeletons *skeletons) +{ + struct nstoken *nstoken = NULL; + int xdp_pass_fd, xdp_tx_fd; + int veth1_ifindex; + int err; + char pkt[ETH_HLEN + 1]; + struct xdp_md ctx_in = {}; + + DECLARE_LIBBPF_OPTS(bpf_test_run_opts, opts, + .data_in = &pkt, + .data_size_in = sizeof(pkt), + .ctx_in = &ctx_in, + .ctx_size_in = sizeof(ctx_in), + .flags = BPF_F_TEST_XDP_LIVE_FRAMES, + .repeat = 1, + .batch_size = 1, + ); + + /* We can't use bonding_setup() because bond will be active */ + SYS(out, "ip netns add ns_rr_no_up"); + nstoken = open_netns("ns_rr_no_up"); + if (!ASSERT_OK_PTR(nstoken, "open ns_rr_no_up")) + goto out; + + /* bond0: active-backup, UP with slave veth0. + * Attaching native XDP to bond0 enables bpf_master_redirect_enabled_key + * globally. + */ + SYS(out, "ip link add bond0 type bond mode active-backup"); + SYS(out, "ip link add veth0 type veth peer name veth0p"); + SYS(out, "ip link set veth0 master bond0"); + SYS(out, "ip link set bond0 up"); + SYS(out, "ip link set veth0p up"); + + /* bond1: round-robin, never UP -> rr_tx_counter stays NULL */ + SYS(out, "ip link add bond1 type bond mode balance-rr"); + SYS(out, "ip link add veth1 type veth peer name veth1p"); + SYS(out, "ip link set veth1 master bond1"); + + veth1_ifindex = if_nametoindex("veth1"); + if (!ASSERT_GT(veth1_ifindex, 0, "veth1_ifindex")) + goto out; + + /* Attach native XDP to bond0 -> enables global redirect key */ + if (xdp_attach(skeletons, skeletons->xdp_tx->progs.xdp_tx, "bond0")) + goto out; + + /* Attach generic XDP (XDP_TX) to veth1. + * When packets arrive at veth1 via netif_receive_skb, do_xdp_generic() + * runs this program. XDP_TX + bond slave triggers xdp_master_redirect(). + */ + xdp_tx_fd = bpf_program__fd(skeletons->xdp_tx->progs.xdp_tx); + if (!ASSERT_GE(xdp_tx_fd, 0, "xdp_tx prog_fd")) + goto out; + + err = bpf_xdp_attach(veth1_ifindex, xdp_tx_fd, + XDP_FLAGS_SKB_MODE, NULL); + if (!ASSERT_OK(err, "attach generic XDP to veth1")) + goto out; + + /* Run BPF_PROG_TEST_RUN with XDP_PASS live frames on veth1. + * XDP_PASS frames become SKBs with skb->dev = veth1, entering + * netif_receive_skb -> do_xdp_generic -> xdp_master_redirect. + * Without the fix, bond_rr_gen_slave_id() dereferences NULL + * rr_tx_counter and crashes. + */ + xdp_pass_fd = bpf_program__fd(skeletons->xdp_dummy->progs.xdp_dummy_prog); + if (!ASSERT_GE(xdp_pass_fd, 0, "xdp_pass prog_fd")) + goto out; + + memset(pkt, 0, sizeof(pkt)); + ctx_in.data_end = sizeof(pkt); + ctx_in.ingress_ifindex = veth1_ifindex; + + err = bpf_prog_test_run_opts(xdp_pass_fd, &opts); + ASSERT_OK(err, "xdp_pass test_run should not crash"); + +out: + link_cleanup(skeletons); + close_netns(nstoken); + SYS_NOFAIL("ip netns del ns_rr_no_up"); +} + static void test_xdp_bonding_features(struct skeletons *skeletons) { LIBBPF_OPTS(bpf_xdp_query_opts, query_opts); @@ -738,6 +832,9 @@ void serial_test_xdp_bonding(void) if (test__start_subtest("xdp_bonding_redirect_multi")) test_xdp_bonding_redirect_multi(&skeletons); + if (test__start_subtest("xdp_bonding_redirect_no_up")) + test_xdp_bonding_redirect_no_up(&skeletons); + out: xdp_dummy__destroy(skeletons.xdp_dummy); xdp_tx__destroy(skeletons.xdp_tx); -- 2.43.0