[PATCH v14 12/12] selftests/bpf: Add verifier tests for dynamic pointers parameters in kfuncs
From: Roberto Sassu <hidden>
Date: 2022-08-30 16:21:36
Also in:
bpf, keyrings, linux-kselftest, lkml
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [selftests] (test runners & infrastructure), kernel selftest framework, the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Shuah Khan, Linus Torvalds
From: Roberto Sassu <roberto.sassu@huawei.com> Add verifier tests to ensure that only supported dynamic pointer types are accepted, that the passed argument is actually a dynamic pointer, and that the passed argument is a pointer to the stack. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> --- .../bpf/verifier/kfunc_dynptr_param.c | 72 +++++++++++++++++++ 1 file changed, 72 insertions(+) create mode 100644 tools/testing/selftests/bpf/verifier/kfunc_dynptr_param.c
diff --git a/tools/testing/selftests/bpf/verifier/kfunc_dynptr_param.c b/tools/testing/selftests/bpf/verifier/kfunc_dynptr_param.c
new file mode 100644
index 000000000000..8abb8d566321
--- /dev/null
+++ b/tools/testing/selftests/bpf/verifier/kfunc_dynptr_param.c@@ -0,0 +1,72 @@ +{ + "kfunc dynamic pointer param: type not supported", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, 0), + BPF_MOV64_REG(BPF_REG_6, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, -16), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_MOV64_IMM(BPF_REG_2, 8), + BPF_MOV64_IMM(BPF_REG_3, 0), + BPF_MOV64_REG(BPF_REG_4, BPF_REG_6), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_ringbuf_reserve_dynptr), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_6), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_6), + BPF_MOV64_IMM(BPF_REG_3, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_6), + BPF_MOV64_IMM(BPF_REG_2, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_ringbuf_discard_dynptr), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .fixup_map_ringbuf = { 3 }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "bpf", + .expected_attach_type = BPF_LSM_MAC, + .flags = BPF_F_SLEEPABLE, + .errstr = "arg#0 pointer type STRUCT bpf_dynptr_kern points to unsupported dynamic pointer type", + .result = REJECT, + .fixup_kfunc_btf_id = { + { "bpf_verify_pkcs7_signature", 12 }, + }, +}, +{ + "kfunc dynamic pointer param: arg not a dynamic pointer", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_1), + BPF_MOV64_IMM(BPF_REG_3, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "bpf", + .expected_attach_type = BPF_LSM_MAC, + .flags = BPF_F_SLEEPABLE, + .errstr = "arg#0 pointer type STRUCT bpf_dynptr_kern must be valid and initialized", + .result = REJECT, + .fixup_kfunc_btf_id = { + { "bpf_verify_pkcs7_signature", 5 }, + }, +}, +{ + "kfunc dynamic pointer param: arg not a pointer to stack", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, 0), + BPF_MOV64_IMM(BPF_REG_2, 0), + BPF_MOV64_IMM(BPF_REG_3, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "bpf", + .expected_attach_type = BPF_LSM_MAC, + .flags = BPF_F_SLEEPABLE, + .errstr = "arg#0 pointer type STRUCT bpf_dynptr_kern not to stack", + .result = REJECT, + .fixup_kfunc_btf_id = { + { "bpf_verify_pkcs7_signature", 3 }, + }, +},
--
2.25.1