[PATCH 5.4 254/389] kexec, KEYS, s390: Make use of built-in and secondary keyring for signature verification

Greg Kroah-Hartman
2022-08-23T11:43:24Z

From: Michal Suchanek <msuchanek@suse.de>

commit 0828c4a39be57768b8788e8cbd0d84683ea757e5 upstream.

commit e23a8020ce4e ("s390/kexec_file: Signature verification prototype")
adds support for KEXEC_SIG verification with keys from platform keyring
but the built-in keys and secondary keyring are not used.

Add support for the built-in keys and secondary keyring as x86 does.

Fixes: e23a8020ce4e ("s390/kexec_file: Signature verification prototype")
Cc: stable@vger.kernel.org
Cc: Philipp Rudo <prudo@linux.ibm.com>
Cc: kexec@lists.infradead.org
Cc: keyrings@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Reviewed-by: "Lee, Chun-Yi" <jlee@suse.com>
Acked-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Coiby Xu <coxu@redhat.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/s390/kernel/machine_kexec_file.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)

--- a/arch/s390/kernel/machine_kexec_file.c
+++ b/arch/s390/kernel/machine_kexec_file.c
@@ -29,6 +29,7 @@ int s390_verify_sig(const char *kernel,
const unsigned long marker_len = sizeof(MODULE_SIG_STRING) - 1;
struct module_signature *ms;
unsigned long sig_len;
+ int ret;

/* Skip signature verification when not secure IPLed. */
if (!ipl_secure_flag)
@@ -63,11 +64,18 @@ int s390_verify_sig(const char *kernel,
return -EBADMSG;
}

- return verify_pkcs7_signature(kernel, kernel_len,
- kernel + kernel_len, sig_len,
- VERIFY_USE_PLATFORM_KEYRING,
- VERIFYING_MODULE_SIGNATURE,
- NULL, NULL);
+ ret = verify_pkcs7_signature(kernel, kernel_len,
+ kernel + kernel_len, sig_len,
+ VERIFY_USE_SECONDARY_KEYRING,
+ VERIFYING_MODULE_SIGNATURE,
+ NULL, NULL);
+ if (ret == -ENOKEY && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING))
+ ret = verify_pkcs7_signature(kernel, kernel_len,
+ kernel + kernel_len, sig_len,
+ VERIFY_USE_PLATFORM_KEYRING,
+ VERIFYING_MODULE_SIGNATURE,
+ NULL, NULL);
+ return ret;
}
#endif /* CONFIG_KEXEC_SIG */