diff mbox series

[RFC,v2,5/7] selftests/bpf: Check if return values of LSM programs are allowed

Message ID 20221207172434.435893-6-roberto.sassu@huaweicloud.com (mailing list archive)
State Changes Requested
Delegated to: Paul Moore
Headers show
Series bpf-lsm: Check return values of security modules | expand

Commit Message

Roberto Sassu Dec. 7, 2022, 5:24 p.m. UTC 
From: Roberto Sassu <roberto.sassu@huawei.com>

Ensure that the eBPF verifier allows to load only LSM programs that return
an allowed value depending on the LSM hook they attach to.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
 .../testing/selftests/bpf/verifier/lsm_ret.c  | 148 ++++++++++++++++++
 1 file changed, 148 insertions(+)
 create mode 100644 tools/testing/selftests/bpf/verifier/lsm_ret.c
diff mbox series

Patch

diff --git a/tools/testing/selftests/bpf/verifier/lsm_ret.c b/tools/testing/selftests/bpf/verifier/lsm_ret.c
new file mode 100644
index 000000000000..c9c9cee8e406
--- /dev/null
+++ b/tools/testing/selftests/bpf/verifier/lsm_ret.c
@@ -0,0 +1,148 @@ 
+{
+	"lsm return value: positive not allowed, return -EPERM",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, -EPERM),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_LSM,
+	.kfunc = "inode_permission",
+	.expected_attach_type = BPF_LSM_MAC,
+	.result = ACCEPT,
+},
+{
+	"lsm return value: positive not allowed, return zero",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_LSM,
+	.kfunc = "inode_permission",
+	.expected_attach_type = BPF_LSM_MAC,
+	.result = ACCEPT,
+},
+{
+	"lsm return value: positive not allowed, return one",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_LSM,
+	.kfunc = "inode_permission",
+	.expected_attach_type = BPF_LSM_MAC,
+	.errstr = "Invalid R0, cannot return 1",
+	.result = REJECT,
+},
+{
+	"lsm return value: zero/positive not allowed, return -EPERM",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, -EPERM),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_LSM,
+	.kfunc = "inode_init_security",
+	.expected_attach_type = BPF_LSM_MAC,
+	.result = ACCEPT,
+},
+{
+	"lsm return value: zero/positive not allowed, return zero",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_LSM,
+	.kfunc = "inode_init_security",
+	.expected_attach_type = BPF_LSM_MAC,
+	.errstr = "Invalid R0, cannot return 0",
+	.result = REJECT,
+},
+{
+	"lsm return value: zero/positive not allowed, return one",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_LSM,
+	.kfunc = "inode_init_security",
+	.expected_attach_type = BPF_LSM_MAC,
+	.errstr = "Invalid R0, cannot return 1",
+	.result = REJECT,
+},
+{
+	"lsm return value: positive allowed, return one",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_LSM,
+	.kfunc = "getprocattr",
+	.expected_attach_type = BPF_LSM_MAC,
+	.result = ACCEPT,
+},
+{
+	"lsm return value: positive allowed, return two",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 2),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_LSM,
+	.kfunc = "getprocattr",
+	.expected_attach_type = BPF_LSM_MAC,
+	.result = ACCEPT,
+},
+{
+	"lsm return value: only one allowed, return one",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_LSM,
+	.kfunc = "audit_rule_match",
+	.expected_attach_type = BPF_LSM_MAC,
+	.result = ACCEPT,
+},
+{
+	"lsm return value: only one allowed, return two",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 2),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_LSM,
+	.kfunc = "audit_rule_match",
+	.expected_attach_type = BPF_LSM_MAC,
+	.errstr = "Invalid R0, cannot return > 1",
+	.result = REJECT,
+},
+{
+	"lsm return value: negative not allowed, return -EPERM",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, -EPERM),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_LSM,
+	.kfunc = "ismaclabel",
+	.expected_attach_type = BPF_LSM_MAC,
+	.errstr = "Invalid R0, cannot return < 0",
+	.result = REJECT,
+},
+{
+	"lsm return value: negative not allowed, return zero",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_LSM,
+	.kfunc = "ismaclabel",
+	.expected_attach_type = BPF_LSM_MAC,
+	.result = ACCEPT,
+},
+{
+	"lsm return value: negative not allowed, return one",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 1),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_LSM,
+	.kfunc = "ismaclabel",
+	.expected_attach_type = BPF_LSM_MAC,
+	.result = ACCEPT,
+},