Re: [LTP] [PATCH v2 16/33] keyctl24: Negative tests for KEYCTL_RESTRICT_KEYRING

[Cyril Hrubis <chrubis@suse.cz>]

> +/*
> + * 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;
> +		}

Maybe it would have been better if we moved the self cycle test to a
seprate testcase, instead of adding special cases to this test...

> +	}
> +
> +	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
> 
> 
> -- 
> Mailing list info: https://lists.linux.it/listinfo/ltp

-- 
Cyril Hrubis
chrubis@suse.cz

-- 
Mailing list info: https://lists.linux.it/listinfo/ltp