From 76d950773cd2a365f492ce973429ae629d58131c Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Mon, 1 Jul 2019 10:38:41 -0700 Subject: selftests/bpf: add verifier tests for wide stores Make sure that wide stores are allowed at proper (aligned) addresses. Note that user_ip6 is naturally aligned on 8-byte boundary, so correct addresses are user_ip6[0] and user_ip6[2]. msg_src_ip6 is, however, aligned on a 4-byte bondary, so only msg_src_ip6[1] can be wide-stored. Cc: Andrii Nakryiko Cc: Yonghong Song Acked-by: Andrii Nakryiko Signed-off-by: Stanislav Fomichev Acked-by: Yonghong Song Signed-off-by: Daniel Borkmann --- tools/testing/selftests/bpf/test_verifier.c | 17 +++++++++-- tools/testing/selftests/bpf/verifier/wide_store.c | 36 +++++++++++++++++++++++ 2 files changed, 50 insertions(+), 3 deletions(-) create mode 100644 tools/testing/selftests/bpf/verifier/wide_store.c diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index c5514daf8865..b0773291012a 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -105,6 +105,7 @@ struct bpf_test { __u64 data64[TEST_DATA_LEN / 8]; }; } retvals[MAX_TEST_RUNS]; + enum bpf_attach_type expected_attach_type; }; /* Note we want this to be 64 bit aligned so that the end of our array is @@ -850,6 +851,7 @@ static void do_test_single(struct bpf_test *test, bool unpriv, int fd_prog, expected_ret, alignment_prevented_execution; int prog_len, prog_type = test->prog_type; struct bpf_insn *prog = test->insns; + struct bpf_load_program_attr attr; int run_errs, run_successes; int map_fds[MAX_NR_MAPS]; const char *expected_err; @@ -881,8 +883,17 @@ static void do_test_single(struct bpf_test *test, bool unpriv, pflags |= BPF_F_STRICT_ALIGNMENT; if (test->flags & F_NEEDS_EFFICIENT_UNALIGNED_ACCESS) pflags |= BPF_F_ANY_ALIGNMENT; - fd_prog = bpf_verify_program(prog_type, prog, prog_len, pflags, - "GPL", 0, bpf_vlog, sizeof(bpf_vlog), 4); + + memset(&attr, 0, sizeof(attr)); + attr.prog_type = prog_type; + attr.expected_attach_type = test->expected_attach_type; + attr.insns = prog; + attr.insns_cnt = prog_len; + attr.license = "GPL"; + attr.log_level = 4; + attr.prog_flags = pflags; + + fd_prog = bpf_load_program_xattr(&attr, bpf_vlog, sizeof(bpf_vlog)); if (fd_prog < 0 && !bpf_probe_prog_type(prog_type, 0)) { printf("SKIP (unsupported program type %d)\n", prog_type); skips++; @@ -912,7 +923,7 @@ static void do_test_single(struct bpf_test *test, bool unpriv, printf("FAIL\nUnexpected success to load!\n"); goto fail_log; } - if (!strstr(bpf_vlog, expected_err)) { + if (!expected_err || !strstr(bpf_vlog, expected_err)) { printf("FAIL\nUnexpected error message!\n\tEXP: %s\n\tRES: %s\n", expected_err, bpf_vlog); goto fail_log; diff --git a/tools/testing/selftests/bpf/verifier/wide_store.c b/tools/testing/selftests/bpf/verifier/wide_store.c new file mode 100644 index 000000000000..8fe99602ded4 --- /dev/null +++ b/tools/testing/selftests/bpf/verifier/wide_store.c @@ -0,0 +1,36 @@ +#define BPF_SOCK_ADDR(field, off, res, err) \ +{ \ + "wide store to bpf_sock_addr." #field "[" #off "]", \ + .insns = { \ + BPF_MOV64_IMM(BPF_REG_0, 1), \ + BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, \ + offsetof(struct bpf_sock_addr, field[off])), \ + BPF_EXIT_INSN(), \ + }, \ + .result = res, \ + .prog_type = BPF_PROG_TYPE_CGROUP_SOCK_ADDR, \ + .expected_attach_type = BPF_CGROUP_UDP6_SENDMSG, \ + .errstr = err, \ +} + +/* user_ip6[0] is u64 aligned */ +BPF_SOCK_ADDR(user_ip6, 0, ACCEPT, + NULL), +BPF_SOCK_ADDR(user_ip6, 1, REJECT, + "invalid bpf_context access off=12 size=8"), +BPF_SOCK_ADDR(user_ip6, 2, ACCEPT, + NULL), +BPF_SOCK_ADDR(user_ip6, 3, REJECT, + "invalid bpf_context access off=20 size=8"), + +/* msg_src_ip6[0] is _not_ u64 aligned */ +BPF_SOCK_ADDR(msg_src_ip6, 0, REJECT, + "invalid bpf_context access off=44 size=8"), +BPF_SOCK_ADDR(msg_src_ip6, 1, ACCEPT, + NULL), +BPF_SOCK_ADDR(msg_src_ip6, 2, REJECT, + "invalid bpf_context access off=52 size=8"), +BPF_SOCK_ADDR(msg_src_ip6, 3, REJECT, + "invalid bpf_context access off=56 size=8"), + +#undef BPF_SOCK_ADDR -- cgit v1.2.3-59-g8ed1b