[PATCH AUTOSEL 6.11 051/244] nvme-keyring: restrict match length for version '1' identifiers

Sasha Levin
2024-09-25T11:38:28Z

From: Hannes Reinecke <hare@kernel.org>

[ Upstream commit 79559c75332458985ab8a21f11b08bf7c9b833b0 ]

TP8018 introduced a new TLS PSK identifier version (version 1), which appended
a PSK hash value to the existing identifier (cf NVMe TCP specification v1.1,
section 3.6.1.3 'TLS PSK and PSK Identity Derivation').
An original (version 0) identifier has the form:

NVMe0<type><hmac> <hostnqn> <subsysnqn>

and a version 1 identifier has the form:

NVMe1<type><hmac> <hostnqn> <subsysnqn> <hash>

This patch modifies the lookup algorthm to compare only the first part
of the identifier (excluding the hash value) to handle both version 0 and
version 1 identifiers.
And the spec declares 'version 0' identifiers obsolete, so the lookup
algorithm is modified to prever v1 identifiers.

Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/nvme/common/keyring.c | 36 +++++++++++++++++++++++++----------
1 file changed, 26 insertions(+), 10 deletions(-)

diff --git a/drivers/nvme/common/keyring.c b/drivers/nvme/common/keyring.c
index 6f7e7a8fa5ae4..05e89307c8aa3 100644
--- a/drivers/nvme/common/keyring.c
+++ b/drivers/nvme/common/keyring.c
@@ -36,14 +36,12 @@ static bool nvme_tls_psk_match(const struct key *key,
pr_debug("%s: no key description\n", __func__);
return false;
}
- match_len = strlen(key->description);
- pr_debug("%s: id %s len %zd\n", __func__, key->description, match_len);
-
if (!match_data->raw_data) {
pr_debug("%s: no match data\n", __func__);
return false;
}
match_id = match_data->raw_data;
+ match_len = strlen(match_id);
pr_debug("%s: match '%s' '%s' len %zd\n",
__func__, match_id, key->description, match_len);
return !memcmp(key->description, match_id, match_len);
@@ -71,7 +69,7 @@ static struct key_type nvme_tls_psk_key_type = {

static struct key *nvme_tls_psk_lookup(struct key *keyring,
const char *hostnqn, const char *subnqn,
- int hmac, bool generated)
+ u8 hmac, u8 psk_ver, bool generated)
{
char *identity;
size_t identity_len = (NVMF_NQN_SIZE) * 2 + 11;
@@ -82,8 +80,8 @@ static struct key *nvme_tls_psk_lookup(struct key *keyring,
if (!identity)
return ERR_PTR(-ENOMEM);

- snprintf(identity, identity_len, "NVMe0%c%02d %s %s",
- generated ? 'G' : 'R', hmac, hostnqn, subnqn);
+ snprintf(identity, identity_len, "NVMe%u%c%02u %s %s",
+ psk_ver, generated ? 'G' : 'R', hmac, hostnqn, subnqn);

if (!keyring)
keyring = nvme_keyring;
@@ -107,21 +105,38 @@ static struct key *nvme_tls_psk_lookup(struct key *keyring,
/*
* NVMe PSK priority list
*
- * 'Retained' PSKs (ie 'generated == false')
- * should be preferred to 'generated' PSKs,
- * and SHA-384 should be preferred to SHA-256.
+ * 'Retained' PSKs (ie 'generated == false') should be preferred to 'generated'
+ * PSKs, PSKs with hash (psk_ver 1) should be preferred to PSKs without hash
+ * (psk_ver 0), and SHA-384 should be preferred to SHA-256.
*/
static struct nvme_tls_psk_priority_list {
bool generated;
+ u8 psk_ver;
enum nvme_tcp_tls_cipher cipher;
} nvme_tls_psk_prio[] = {
{ .generated = false,
+ .psk_ver = 1,
+ .cipher = NVME_TCP_TLS_CIPHER_SHA384, },
+ { .generated = false,
+ .psk_ver = 1,
+ .cipher = NVME_TCP_TLS_CIPHER_SHA256, },
+ { .generated = false,
+ .psk_ver = 0,
.cipher = NVME_TCP_TLS_CIPHER_SHA384, },
{ .generated = false,
+ .psk_ver = 0,
+ .cipher = NVME_TCP_TLS_CIPHER_SHA256, },
+ { .generated = true,
+ .psk_ver = 1,
+ .cipher = NVME_TCP_TLS_CIPHER_SHA384, },
+ { .generated = true,
+ .psk_ver = 1,
.cipher = NVME_TCP_TLS_CIPHER_SHA256, },
{ .generated = true,
+ .psk_ver = 0,
.cipher = NVME_TCP_TLS_CIPHER_SHA384, },
{ .generated = true,
+ .psk_ver = 0,
.cipher = NVME_TCP_TLS_CIPHER_SHA256, },
};

@@ -137,10 +152,11 @@ key_serial_t nvme_tls_psk_default(struct key *keyring,

for (prio = 0; prio < ARRAY_SIZE(nvme_tls_psk_prio); prio++) {
bool generated = nvme_tls_psk_prio[prio].generated;
+ u8 ver = nvme_tls_psk_prio[prio].psk_ver;
enum nvme_tcp_tls_cipher cipher = nvme_tls_psk_prio[prio].cipher;

tls_key = nvme_tls_psk_lookup(keyring, hostnqn, subnqn,
- cipher, generated);
+ cipher, ver, generated);
if (!IS_ERR(tls_key)) {
tls_key_id = tls_key->serial;
key_put(tls_key);
--
2.43.0