Check what happens if non-offloaded dev bound BPF program is followed by offloaded dev bound program. Test case adapated from syzbot report [1]. [1] https://lore.kernel.org/bpf/000000000000d97f3c060479c4f8@xxxxxxxxxx/ Signed-off-by: Eduard Zingerman <eddyz87@xxxxxxxxx> --- .../bpf/prog_tests/xdp_dev_bound_only.c | 58 +++++++++++++++++++ 1 file changed, 58 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/xdp_dev_bound_only.c diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_dev_bound_only.c b/tools/testing/selftests/bpf/prog_tests/xdp_dev_bound_only.c new file mode 100644 index 000000000000..5ee4c16d2e21 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/xdp_dev_bound_only.c @@ -0,0 +1,58 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <net/if.h> +#include <test_progs.h> +#include <network_helpers.h> + +#define LOCAL_NETNS "xdp_dev_bound_only_netns" + +int load_dummy_prog(char *name, __u32 ifindex, __u32 flags) +{ + struct bpf_insn insns[] = { BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN() }; + LIBBPF_OPTS(bpf_prog_load_opts, opts); + + opts.prog_flags = flags; + opts.prog_ifindex = ifindex; + return bpf_prog_load(BPF_PROG_TYPE_XDP, name, "GPL", insns, ARRAY_SIZE(insns), &opts); +} + +/* A test case for bpf_offload_netdev->offload handling bug: + * - create a veth device (does not support offload); + * - create a device bound XDP program with BPF_F_XDP_DEV_BOUND_ONLY flag + * (such programs are not offloaded); + * - create a device bound XDP program without flags (such programs are offloaded). + * This might lead to 'BUG: kernel NULL pointer dereference'. + */ +void test_xdp_dev_bound_only_offdev(void) +{ + struct nstoken *tok = NULL; + __u32 ifindex; + int fd1 = -1; + int fd2 = -1; + + SYS(out, "ip netns add " LOCAL_NETNS); + tok = open_netns(LOCAL_NETNS); + SYS(out, "ip link add eth42 type veth"); + ifindex = if_nametoindex("eth42"); + if (!ASSERT_NEQ(ifindex, 0, "if_nametoindex")) { + perror("if_nametoindex"); + goto out; + } + fd1 = load_dummy_prog("dummy1", ifindex, BPF_F_XDP_DEV_BOUND_ONLY); + if (!ASSERT_GE(fd1, 0, "load_dummy_prog #1")) { + perror("load_dummy_prog #1"); + goto out; + } + /* Program with ifindex is considered offloaded, however veth + * does not support offload => error should be reported. + */ + fd2 = load_dummy_prog("dummy2", ifindex, 0); + ASSERT_EQ(fd2, -EINVAL, "load_dummy_prog #2 (offloaded)"); + +out: + close(fd1); + close(fd2); + SYS_NOFAIL("ip link delete eth42"); + SYS_NOFAIL("ip netns del " LOCAL_NETNS); + if (tok) + close_netns(tok); +} -- 2.41.0
