diff mbox series

[v7,5/7] selftests: Add verifier tests for bpf_lookup_user_key() and bpf_key_put()

Message ID 20220712184128.999301-6-roberto.sassu@huawei.com (mailing list archive)
State Changes Requested
Delegated to: BPF
Headers show
Series bpf: Add bpf_verify_pkcs7_signature() helper | expand

Checks

Context Check Description
bpf/vmtest-bpf-next-VM_Test-3 fail Logs for Kernel LATEST on z15 with gcc
bpf/vmtest-bpf-next-PR fail PR summary
netdev/tree_selection success Guessed tree name to be net-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers warning 5 maintainers not CCed: haoluo@google.com memxor@gmail.com mykolal@fb.com jolsa@kernel.org sdf@google.com
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 81 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
bpf/vmtest-bpf-next-VM_Test-1 success Logs for Kernel LATEST on ubuntu-latest with gcc
bpf/vmtest-bpf-next-VM_Test-2 success Logs for Kernel LATEST on ubuntu-latest with llvm-15

Commit Message

Roberto Sassu July 12, 2022, 6:41 p.m. UTC 
Add verifier tests for bpf_lookup_user_key() and bpf_key_put(), to ensure
that acquired key references can be released, that a non-NULL pointer is
passed to bpf_key_put(), and that key references are not leaked.

Also, slightly modify test_verifier.c, to find the BTF ID of the attach
point for the LSM program type (currently, it is done only for TRACING).

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
 tools/testing/selftests/bpf/test_verifier.c   |  3 +-
 .../selftests/bpf/verifier/ref_tracking.c     | 66 +++++++++++++++++++
 2 files changed, 68 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index f9d553fbf68a..2dbcbf363c18 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -1498,7 +1498,8 @@  static void do_test_single(struct bpf_test *test, bool unpriv,
 		opts.log_level = DEFAULT_LIBBPF_LOG_LEVEL;
 	opts.prog_flags = pflags;
 
-	if (prog_type == BPF_PROG_TYPE_TRACING && test->kfunc) {
+	if ((prog_type == BPF_PROG_TYPE_TRACING ||
+	     prog_type == BPF_PROG_TYPE_LSM) && test->kfunc) {
 		int attach_btf_id;
 
 		attach_btf_id = libbpf_find_vmlinux_btf_id(test->kfunc,
diff --git a/tools/testing/selftests/bpf/verifier/ref_tracking.c b/tools/testing/selftests/bpf/verifier/ref_tracking.c
index 57a83d763ec1..36e0b9b342de 100644
--- a/tools/testing/selftests/bpf/verifier/ref_tracking.c
+++ b/tools/testing/selftests/bpf/verifier/ref_tracking.c
@@ -84,6 +84,72 @@ 
 	.errstr = "Unreleased reference",
 	.result = REJECT,
 },
+{
+	"reference tracking: release key reference",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_1, -3),
+	BPF_MOV64_IMM(BPF_REG_2, 0),
+	BPF_EMIT_CALL(BPF_FUNC_lookup_user_key),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+	BPF_EMIT_CALL(BPF_FUNC_key_put),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_LSM,
+	.kfunc = "bpf",
+	.expected_attach_type = BPF_LSM_MAC,
+	.flags = BPF_F_SLEEPABLE,
+	.result = ACCEPT,
+},
+{
+	"reference tracking: release key reference without check",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_1, -3),
+	BPF_MOV64_IMM(BPF_REG_2, 0),
+	BPF_EMIT_CALL(BPF_FUNC_lookup_user_key),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+	BPF_EMIT_CALL(BPF_FUNC_key_put),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_LSM,
+	.kfunc = "bpf",
+	.expected_attach_type = BPF_LSM_MAC,
+	.flags = BPF_F_SLEEPABLE,
+	.errstr = "type=ptr_or_null_ expected=ptr_",
+	.result = REJECT,
+},
+{
+	"reference tracking: release reference with NULL key pointer",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_1, 0),
+	BPF_EMIT_CALL(BPF_FUNC_key_put),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_LSM,
+	.kfunc = "bpf",
+	.expected_attach_type = BPF_LSM_MAC,
+	.flags = BPF_F_SLEEPABLE,
+	.errstr = "type=scalar expected=ptr_",
+	.result = REJECT,
+},
+{
+	"reference tracking: leak potential reference to key",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_1, -3),
+	BPF_MOV64_IMM(BPF_REG_2, 0),
+	BPF_EMIT_CALL(BPF_FUNC_lookup_user_key),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_LSM,
+	.kfunc = "bpf",
+	.expected_attach_type = BPF_LSM_MAC,
+	.flags = BPF_F_SLEEPABLE,
+	.errstr = "Unreleased reference",
+	.result = REJECT,
+},
 {
 	"reference tracking: release reference without check",
 	.insns = {