[PATCH v2 04/18] certs: Create blacklist keyring earlier

Lukas Wunner
2024-06-30T20:03:43Z

The upcoming support for PCI device authentication with CMA-SPDM
(PCIe r6.2 sec 6.31) requires parsing X.509 certificates upon
device enumeration, which happens in a subsys_initcall().

Parsing X.509 certificates accesses the blacklist keyring:
x509_cert_parse()
x509_get_sig_params()
is_hash_blacklisted()
keyring_search()

So far the keyring is created much later in a device_initcall(). Avoid
a NULL pointer dereference on access to the keyring by creating it one
initcall level earlier than PCI device enumeration, i.e. in an
arch_initcall().

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
certs/blacklist.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/certs/blacklist.c b/certs/blacklist.c
index 675dd7a8f07a..34185415d451 100644
--- a/certs/blacklist.c
+++ b/certs/blacklist.c
@@ -311,7 +311,7 @@ static int restrict_link_for_blacklist(struct key *dest_keyring,
* Initialise the blacklist
*
* The blacklist_init() function is registered as an initcall via
- * device_initcall(). As a result if the blacklist_init() function fails for
+ * arch_initcall(). As a result if the blacklist_init() function fails for
* any reason the kernel continues to execute. While cleanly returning -ENODEV
* could be acceptable for some non-critical kernel parts, if the blacklist
* keyring fails to load it defeats the certificate/key based deny list for
@@ -356,7 +356,7 @@ static int __init blacklist_init(void)
/*
* Must be initialised before we try and load the keys into the keyring.
*/
-device_initcall(blacklist_init);
+arch_initcall(blacklist_init);

#ifdef CONFIG_SYSTEM_REVOCATION_LIST
/*
--
2.43.0