From 6d5f1ef838683efba01bacb7854f6516fbcbae17 Mon Sep 17 00:00:00 2001 From: Jussi Maki Date: Mon, 6 Sep 2021 10:56:37 +0200 Subject: bonding: Fix negative jump label count on nested bonding With nested bonding devices the nested bond device's ndo_bpf was called without a program causing it to decrement the static key without a prior increment leading to negative count. Fix the issue by 1) only calling slave's ndo_bpf when there's a program to be loaded and 2) only decrement the count when a program is unloaded. Fixes: 9e2ee5c7e7c3 ("net, bonding: Add XDP support to the bonding driver") Reported-by: syzbot+30622fb04ddd72a4d167@syzkaller.appspotmail.com Signed-off-by: Jussi Maki Signed-off-by: David S. Miller --- drivers/net/bonding/bond_main.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 3858da3d3ea7..77dc79a7f574 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -2169,7 +2169,7 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev, res = -EOPNOTSUPP; goto err_sysfs_del; } - } else { + } else if (bond->xdp_prog) { struct netdev_bpf xdp = { .command = XDP_SETUP_PROG, .flags = 0, @@ -5224,13 +5224,12 @@ static int bond_xdp_set(struct net_device *dev, struct bpf_prog *prog, bpf_prog_inc(prog); } - if (old_prog) - bpf_prog_put(old_prog); - - if (prog) + if (prog) { static_branch_inc(&bpf_master_redirect_enabled_key); - else + } else if (old_prog) { + bpf_prog_put(old_prog); static_branch_dec(&bpf_master_redirect_enabled_key); + } return 0; -- cgit v1.2.3 From 4a9c93dc47de335880ce7347e6aa006d8f33265a Mon Sep 17 00:00:00 2001 From: Jussi Maki Date: Mon, 6 Sep 2021 10:56:38 +0200 Subject: selftests/bpf: Test XDP bonding nest and unwind Modify the test to check that enslaving a bond slave with a XDP program is now allowed. Extend attach test to exercise the program unwinding in bond_xdp_set and add a new test for loading XDP program on doubly nested bond device to verify that static key incr/decr is correct. Signed-off-by: Jussi Maki Signed-off-by: David S. Miller --- .../testing/selftests/bpf/prog_tests/xdp_bonding.c | 74 +++++++++++++++++++--- 1 file changed, 64 insertions(+), 10 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_bonding.c b/tools/testing/selftests/bpf/prog_tests/xdp_bonding.c index 370d220288a6..ad3ba81b4048 100644 --- a/tools/testing/selftests/bpf/prog_tests/xdp_bonding.c +++ b/tools/testing/selftests/bpf/prog_tests/xdp_bonding.c @@ -384,8 +384,7 @@ static void test_xdp_bonding_attach(struct skeletons *skeletons) { struct bpf_link *link = NULL; struct bpf_link *link2 = NULL; - int veth, bond; - int err; + int veth, bond, err; if (!ASSERT_OK(system("ip link add veth type veth"), "add veth")) goto out; @@ -399,22 +398,18 @@ static void test_xdp_bonding_attach(struct skeletons *skeletons) if (!ASSERT_GE(bond, 0, "if_nametoindex bond")) goto out; - /* enslaving with a XDP program loaded fails */ + /* enslaving with a XDP program loaded is allowed */ link = bpf_program__attach_xdp(skeletons->xdp_dummy->progs.xdp_dummy_prog, veth); if (!ASSERT_OK_PTR(link, "attach program to veth")) goto out; err = system("ip link set veth master bond"); - if (!ASSERT_NEQ(err, 0, "attaching slave with xdp program expected to fail")) + if (!ASSERT_OK(err, "set veth master")) goto out; bpf_link__destroy(link); link = NULL; - err = system("ip link set veth master bond"); - if (!ASSERT_OK(err, "set veth master")) - goto out; - /* attaching to slave when master has no program is allowed */ link = bpf_program__attach_xdp(skeletons->xdp_dummy->progs.xdp_dummy_prog, veth); if (!ASSERT_OK_PTR(link, "attach program to slave when enslaved")) @@ -434,8 +429,26 @@ static void test_xdp_bonding_attach(struct skeletons *skeletons) goto out; /* attaching to slave not allowed when master has program loaded */ - link2 = bpf_program__attach_xdp(skeletons->xdp_dummy->progs.xdp_dummy_prog, bond); - ASSERT_ERR_PTR(link2, "attach program to slave when master has program"); + link2 = bpf_program__attach_xdp(skeletons->xdp_dummy->progs.xdp_dummy_prog, veth); + if (!ASSERT_ERR_PTR(link2, "attach program to slave when master has program")) + goto out; + + bpf_link__destroy(link); + link = NULL; + + /* test program unwinding with a non-XDP slave */ + if (!ASSERT_OK(system("ip link add vxlan type vxlan id 1 remote 1.2.3.4 dstport 0 dev lo"), + "add vxlan")) + goto out; + + err = system("ip link set vxlan master bond"); + if (!ASSERT_OK(err, "set vxlan master")) + goto out; + + /* attaching not allowed when one slave does not support XDP */ + link = bpf_program__attach_xdp(skeletons->xdp_dummy->progs.xdp_dummy_prog, bond); + if (!ASSERT_ERR_PTR(link, "attach program to master when slave does not support XDP")) + goto out; out: bpf_link__destroy(link); @@ -443,6 +456,44 @@ out: system("ip link del veth"); system("ip link del bond"); + system("ip link del vxlan"); +} + +/* Test with nested bonding devices to catch issue with negative jump label count */ +static void test_xdp_bonding_nested(struct skeletons *skeletons) +{ + struct bpf_link *link = NULL; + int bond, err; + + if (!ASSERT_OK(system("ip link add bond type bond"), "add bond")) + goto out; + + bond = if_nametoindex("bond"); + if (!ASSERT_GE(bond, 0, "if_nametoindex bond")) + goto out; + + if (!ASSERT_OK(system("ip link add bond_nest1 type bond"), "add bond_nest1")) + goto out; + + err = system("ip link set bond_nest1 master bond"); + if (!ASSERT_OK(err, "set bond_nest1 master")) + goto out; + + if (!ASSERT_OK(system("ip link add bond_nest2 type bond"), "add bond_nest1")) + goto out; + + err = system("ip link set bond_nest2 master bond_nest1"); + if (!ASSERT_OK(err, "set bond_nest2 master")) + goto out; + + link = bpf_program__attach_xdp(skeletons->xdp_dummy->progs.xdp_dummy_prog, bond); + ASSERT_OK_PTR(link, "attach program to master"); + +out: + bpf_link__destroy(link); + system("ip link del bond"); + system("ip link del bond_nest1"); + system("ip link del bond_nest2"); } static int libbpf_debug_print(enum libbpf_print_level level, @@ -496,6 +547,9 @@ void test_xdp_bonding(void) if (test__start_subtest("xdp_bonding_attach")) test_xdp_bonding_attach(&skeletons); + if (test__start_subtest("xdp_bonding_nested")) + test_xdp_bonding_nested(&skeletons); + for (i = 0; i < ARRAY_SIZE(bond_test_cases); i++) { struct bond_test_case *test_case = &bond_test_cases[i]; -- cgit v1.2.3