[LTP] [PATCH v2 16/33] keyctl24: Negative tests for KEYCTL_RESTRICT_KEYRING
Andrea Cervesato
andrea.cervesato@suse.de
Fri Sep 4 14:09:05 CEST 2026
From: Andrea Cervesato <andrea.cervesato@suse.com>
Test error conditions of KEYCTL_RESTRICT_KEYRING using a parameterized
tcase table: invalid type/restriction combinations (EINVAL), non-keyrings
(ENOTDIR), unknown key type (ENOKEY), key type without lookup (ENOENT),
invalid restriction string (EINVAL), bogus key serial (ENOKEY), already
restricted (EEXIST), self-chain cycle (EDEADLK), and missing Setattr
(EACCES).
Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
---
runtest/syscalls | 1 +
testcases/kernel/syscalls/keyctl/.gitignore | 1 +
testcases/kernel/syscalls/keyctl/keyctl24.c | 173 ++++++++++++++++++++++++++++
3 files changed, 175 insertions(+)
diff --git a/runtest/syscalls b/runtest/syscalls
index f7c4830a9..be35e9f93 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -741,6 +741,7 @@ keyctl20 keyctl20
keyctl21 keyctl21
keyctl22 keyctl22
keyctl23 keyctl23
+keyctl24 keyctl24
kcmp01 kcmp01
kcmp02 kcmp02
diff --git a/testcases/kernel/syscalls/keyctl/.gitignore b/testcases/kernel/syscalls/keyctl/.gitignore
index 803e4e94c..767ccf61a 100644
--- a/testcases/kernel/syscalls/keyctl/.gitignore
+++ b/testcases/kernel/syscalls/keyctl/.gitignore
@@ -21,3 +21,4 @@
/keyctl21
/keyctl22
/keyctl23
+/keyctl24
diff --git a/testcases/kernel/syscalls/keyctl/keyctl24.c b/testcases/kernel/syscalls/keyctl/keyctl24.c
new file mode 100644
index 000000000..2ec78e720
--- /dev/null
+++ b/testcases/kernel/syscalls/keyctl/keyctl24.c
@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2026 Andrea Cervesato <andrea.cervesato@suse.com>
+ */
+
+/*\
+ * Negative test cases for ``KEYCTL_RESTRICT_KEYRING`` of :manpage:`keyctl(2)`.
+ *
+ * [Algorithm]
+ *
+ * - restrict with ``NULL`` type and non-NULL restriction fails with ``EINVAL``
+ * - restrict with non-NULL type and ``NULL`` restriction fails with ``EINVAL``
+ * - restrict on a non-keyring key fails with ``ENOTDIR``
+ * - restrict with unknown key type fails with ``ENOKEY``
+ * - restrict with key type having no restriction lookup fails with ``ENOENT``
+ * - restrict with asymmetric type and invalid restriction string fails with
+ * ``EINVAL``
+ * - restrict with asymmetric type and bogus key serial fails with ``ENOKEY``
+ * - restrict an already restricted keyring fails with ``EEXIST``
+ * - restrict with self-referencing key_or_keyring chain fails with ``EDEADLK``
+ * - restrict without Setattr permission fails with ``EACCES``
+ */
+
+#include <stdio.h>
+
+#include "keyctl_common.h"
+
+static key_serial_t ring_reject, ring_no_setattr;
+static key_serial_t user_key;
+static int asym_supported;
+
+/*
+ * A tcase with .id = NULL asks verify_negative() to allocate a fresh
+ * unrestricted keyring for the case and unlink it afterwards, so that a
+ * false-positive result cannot restrict a ring shared with later cases.
+ * .self_cycle asks for a "key_or_keyring:<fresh>:chain" restriction string
+ * pointing back at that fresh ring, needed for the EDEADLK check.
+ */
+static struct tcase {
+ key_serial_t *id;
+ int self_cycle;
+ const char *type;
+ const char *restriction;
+ int exp_errno;
+ int needs_asym;
+ const char *desc;
+} tcases[] = {
+ {
+ .restriction = "builtin_trusted",
+ .exp_errno = EINVAL,
+ .desc = "NULL type and non-NULL restriction",
+ },
+ {
+ .type = "asymmetric",
+ .exp_errno = EINVAL,
+ .desc = "non-NULL type and NULL restriction",
+ },
+ {
+ .id = &user_key,
+ .exp_errno = ENOTDIR,
+ .desc = "non-keyring key",
+ },
+ {
+ .type = "nosuchtype",
+ .restriction = "builtin_trusted",
+ .exp_errno = ENOKEY,
+ .desc = "unknown key type",
+ },
+ {
+ .type = "user",
+ .restriction = "builtin_trusted",
+ .exp_errno = ENOENT,
+ .desc = "key type having no lookup_restriction",
+ },
+ {
+ .type = "asymmetric",
+ .restriction = "bogus",
+ .exp_errno = EINVAL,
+ .needs_asym = 1,
+ .desc = "asymmetric with invalid restriction string",
+ },
+ {
+ .type = "asymmetric",
+ .restriction = "key_or_keyring:2147483647",
+ .exp_errno = ENOKEY,
+ .needs_asym = 1,
+ .desc = "asymmetric with bogus key serial",
+ },
+ {
+ .id = &ring_reject,
+ .exp_errno = EEXIST,
+ .desc = "already restricted keyring",
+ },
+ {
+ .self_cycle = 1,
+ .type = "asymmetric",
+ .exp_errno = EDEADLK,
+ .needs_asym = 1,
+ .desc = "self-referencing key_or_keyring chain",
+ },
+ {
+ .id = &ring_no_setattr,
+ .exp_errno = EACCES,
+ .desc = "keyring without Setattr permission",
+ },
+};
+
+static void setup(void)
+{
+ key_serial_t probe_ring;
+
+ SAFE_KEYCTL(KEYCTL_JOIN_SESSION_KEYRING, 0, 0, 0, 0);
+
+ ring_reject = new_ring("ltpkeyctl24_reject");
+ ring_no_setattr = new_ring("ltpkeyctl24_no_setattr");
+ SAFE_KEYCTL(KEYCTL_SETPERM, ring_no_setattr, KEY_PERM_NO_SETATTR, 0, 0);
+
+ /* Permanently restrict ring_reject with reject-all for EEXIST test */
+ SAFE_KEYCTL(KEYCTL_RESTRICT_KEYRING, ring_reject, 0, 0, 0);
+
+ user_key = new_user_key("k", "payload", 7, KEY_SPEC_PROCESS_KEYRING);
+
+ /* Probe asymmetric support on a throwaway ring so we cannot poison
+ * any ring reused later by the tcase table.
+ */
+ probe_ring = new_ring("ltpkeyctl24_probe");
+ TEST(keyctl(KEYCTL_RESTRICT_KEYRING, probe_ring,
+ (unsigned long)"asymmetric", (unsigned long)"bogus", 0));
+ asym_supported = (TST_RET != -1 || TST_ERR != ENODEV);
+ keyctl(KEYCTL_UNLINK, probe_ring, KEY_SPEC_PROCESS_KEYRING, 0, 0);
+}
+
+static void verify_negative(unsigned int n)
+{
+ struct tcase *tc = &tcases[n];
+ key_serial_t id, fresh_ring = 0;
+ const char *restriction = tc->restriction;
+ char cycle_buf[64];
+
+ if (tc->needs_asym && !asym_supported) {
+ tst_res(TCONF, "asymmetric key type not supported");
+ return;
+ }
+
+ if (tc->id) {
+ id = *tc->id;
+ } else {
+ fresh_ring = new_ring("ltpkeyctl24_fresh");
+ id = fresh_ring;
+ if (tc->self_cycle) {
+ snprintf(cycle_buf, sizeof(cycle_buf),
+ "key_or_keyring:%d:chain", fresh_ring);
+ restriction = cycle_buf;
+ }
+ }
+
+ TST_EXP_FAIL(keyctl(KEYCTL_RESTRICT_KEYRING, (unsigned long)id,
+ (unsigned long)tc->type,
+ (unsigned long)restriction, 0),
+ tc->exp_errno,
+ "KEYCTL_RESTRICT_KEYRING with %s", tc->desc);
+
+ if (fresh_ring)
+ keyctl(KEYCTL_UNLINK, fresh_ring, KEY_SPEC_PROCESS_KEYRING,
+ 0, 0);
+}
+
+static struct tst_test test = {
+ .setup = setup,
+ .test = verify_negative,
+ .tcnt = ARRAY_SIZE(tcases),
+ .min_kver = "4.12",
+};
--
2.51.0
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