[LTP] [PATCH v2 31/33] keyctl37: Negative tests for KEYCTL_CAPABILITIES

[Andrea Cervesato]

From: Andrea Cervesato <andrea.cervesato@suse.com>

Add negative test cases for KEYCTL_CAPABILITIES verifying that
passing a NULL buffer with a non-zero length or an invalid buffer
pointer fails with EFAULT.

Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
---
 runtest/syscalls                            |  1 +
 testcases/kernel/syscalls/keyctl/.gitignore |  1 +
 testcases/kernel/syscalls/keyctl/keyctl37.c | 63 +++++++++++++++++++++++++++++
 3 files changed, 65 insertions(+)

diff --git a/runtest/syscalls b/runtest/syscalls
index 8ad8f0fe5..66215afd7 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -754,6 +754,7 @@ keyctl33 keyctl33
 keyctl34 keyctl34
 keyctl35 keyctl35
 keyctl36 keyctl36
+keyctl37 keyctl37
 
 kcmp01 kcmp01
 kcmp02 kcmp02
diff --git a/testcases/kernel/syscalls/keyctl/.gitignore b/testcases/kernel/syscalls/keyctl/.gitignore
index a4da8ae80..7ee6b9098 100644
--- a/testcases/kernel/syscalls/keyctl/.gitignore
+++ b/testcases/kernel/syscalls/keyctl/.gitignore
@@ -34,3 +34,4 @@
 /keyctl34
 /keyctl35
 /keyctl36
+/keyctl37
diff --git a/testcases/kernel/syscalls/keyctl/keyctl37.c b/testcases/kernel/syscalls/keyctl/keyctl37.c
new file mode 100644
index 000000000..08d1db03b
--- /dev/null
+++ b/testcases/kernel/syscalls/keyctl/keyctl37.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2026 Andrea Cervesato <andrea.cervesato@suse.com>
+ */
+
+/*\
+ * Negative test cases for ``KEYCTL_CAPABILITIES`` of :manpage:`keyctl(2)`.
+ *
+ * [Algorithm]
+ *
+ * - verify ``KEYCTL_CAPABILITIES`` with NULL buffer and ``buflen > 0`` fails with ``EFAULT``
+ * - verify ``KEYCTL_CAPABILITIES`` with invalid pointer fails with ``EFAULT``
+ */
+
+#include "keyctl_common.h"
+
+static void *bad_addr;
+
+static struct tcase {
+	void **buf;
+	size_t buflen;
+	int exp_errno;
+	const char *desc;
+} tcases[] = {
+	{
+		.buf = NULL,
+		.buflen = 1,
+		.exp_errno = EFAULT,
+		.desc = "NULL buffer with non-zero buflen",
+	},
+	{
+		.buf = &bad_addr,
+		.buflen = 1,
+		.exp_errno = EFAULT,
+		.desc = "invalid buffer pointer",
+	},
+};
+
+static void setup(void)
+{
+	bad_addr = tst_get_bad_addr(NULL);
+}
+
+static void run(unsigned int n)
+{
+	struct tcase *tc = &tcases[n];
+	void *p = tc->buf ? *tc->buf : NULL;
+
+	TST_EXP_FAIL2(keyctl(KEYCTL_CAPABILITIES, (unsigned long)p, tc->buflen, 0, 0),
+		      tc->exp_errno,
+		      "%s", tc->desc);
+}
+
+static struct tst_test test = {
+	.setup = setup,
+	.test = run,
+	.tcnt = ARRAY_SIZE(tcases),
+	.min_kver = "5.3",
+	.needs_kconfigs = (const char *[]) {
+		"CONFIG_KEYS=y",
+		NULL
+	},
+};

-- 
2.51.0