From 23599ada0e9173e92d3cc26254b1e18e542c469d Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Fri, 27 Mar 2020 16:58:56 +0100 Subject: [PATCH] bpf: Add selftest cases for ctx_or_null argument type Add various tests to make sure the verifier keeps catching them: # ./test_verifier [...] #230/p pass ctx or null check, 1: ctx OK #231/p pass ctx or null check, 2: null OK #232/p pass ctx or null check, 3: 1 OK #233/p pass ctx or null check, 4: ctx - const OK #234/p pass ctx or null check, 5: null (connect) OK #235/p pass ctx or null check, 6: null (bind) OK #236/p pass ctx or null check, 7: ctx (bind) OK #237/p pass ctx or null check, 8: null (bind) OK [...] Summary: 1595 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/c74758d07b1b678036465ef7f068a49e9efd3548.1585323121.git.daniel@iogearbox.net --- tools/testing/selftests/bpf/verifier/ctx.c | 105 +++++++++++++++++++++++++++++ 1 file changed, 105 insertions(+) diff --git a/tools/testing/selftests/bpf/verifier/ctx.c b/tools/testing/selftests/bpf/verifier/ctx.c index 92762c0..93d6b16 100644 --- a/tools/testing/selftests/bpf/verifier/ctx.c +++ b/tools/testing/selftests/bpf/verifier/ctx.c @@ -91,3 +91,108 @@ .result = REJECT, .errstr = "variable ctx access var_off=(0x0; 0x4)", }, +{ + "pass ctx or null check, 1: ctx", + .insns = { + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_get_netns_cookie), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_CGROUP_SOCK_ADDR, + .expected_attach_type = BPF_CGROUP_UDP6_SENDMSG, + .result = ACCEPT, +}, +{ + "pass ctx or null check, 2: null", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_get_netns_cookie), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_CGROUP_SOCK_ADDR, + .expected_attach_type = BPF_CGROUP_UDP6_SENDMSG, + .result = ACCEPT, +}, +{ + "pass ctx or null check, 3: 1", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, 1), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_get_netns_cookie), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_CGROUP_SOCK_ADDR, + .expected_attach_type = BPF_CGROUP_UDP6_SENDMSG, + .result = REJECT, + .errstr = "R1 type=inv expected=ctx", +}, +{ + "pass ctx or null check, 4: ctx - const", + .insns = { + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -612), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_get_netns_cookie), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_CGROUP_SOCK_ADDR, + .expected_attach_type = BPF_CGROUP_UDP6_SENDMSG, + .result = REJECT, + .errstr = "dereference of modified ctx ptr", +}, +{ + "pass ctx or null check, 5: null (connect)", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_get_netns_cookie), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_CGROUP_SOCK_ADDR, + .expected_attach_type = BPF_CGROUP_INET4_CONNECT, + .result = ACCEPT, +}, +{ + "pass ctx or null check, 6: null (bind)", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_get_netns_cookie), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_CGROUP_SOCK, + .expected_attach_type = BPF_CGROUP_INET4_POST_BIND, + .result = ACCEPT, +}, +{ + "pass ctx or null check, 7: ctx (bind)", + .insns = { + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_get_socket_cookie), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_CGROUP_SOCK, + .expected_attach_type = BPF_CGROUP_INET4_POST_BIND, + .result = ACCEPT, +}, +{ + "pass ctx or null check, 8: null (bind)", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_get_socket_cookie), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_CGROUP_SOCK, + .expected_attach_type = BPF_CGROUP_INET4_POST_BIND, + .result = REJECT, + .errstr = "R1 type=inv expected=ctx", +}, -- 2.7.4