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authorLinus Torvalds <torvalds@linux-foundation.org>2018-08-15 22:54:12 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-08-15 22:54:12 -0700
commitf91e654474d413201ae578820fb63f8a811f6c4e (patch)
tree7f32d5757381b3371dbf095510622472c7d3aa43 /security/integrity/digsig_asymmetric.c
parentc715ebeb0303b196f17376f189ae4e168d98b563 (diff)
parent3dd0f18c70d94ca2432c78c5735744429f071b0b (diff)
Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull integrity updates from James Morris: "This adds support for EVM signatures based on larger digests, contains a new audit record AUDIT_INTEGRITY_POLICY_RULE to differentiate the IMA policy rules from the IMA-audit messages, addresses two deadlocks due to either loading or searching for crypto algorithms, and cleans up the audit messages" * 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: EVM: fix return value check in evm_write_xattrs() integrity: prevent deadlock during digsig verification. evm: Allow non-SHA1 digital signatures evm: Don't deadlock if a crypto algorithm is unavailable integrity: silence warning when CONFIG_SECURITYFS is not enabled ima: Differentiate auditing policy rules from "audit" actions ima: Do not audit if CONFIG_INTEGRITY_AUDIT is not set ima: Use audit_log_format() rather than audit_log_string() ima: Call audit_log_string() rather than logging it untrusted
Diffstat (limited to 'security/integrity/digsig_asymmetric.c')
-rw-r--r--security/integrity/digsig_asymmetric.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/security/integrity/digsig_asymmetric.c b/security/integrity/digsig_asymmetric.c
index ab6a029062a1..6dc075144508 100644
--- a/security/integrity/digsig_asymmetric.c
+++ b/security/integrity/digsig_asymmetric.c
@@ -115,3 +115,26 @@ int asymmetric_verify(struct key *keyring, const char *sig,
pr_debug("%s() = %d\n", __func__, ret);
return ret;
}
+
+/**
+ * integrity_kernel_module_request - prevent crypto-pkcs1pad(rsa,*) requests
+ * @kmod_name: kernel module name
+ *
+ * We have situation, when public_key_verify_signature() in case of RSA
+ * algorithm use alg_name to store internal information in order to
+ * construct an algorithm on the fly, but crypto_larval_lookup() will try
+ * to use alg_name in order to load kernel module with same name.
+ * Since we don't have any real "crypto-pkcs1pad(rsa,*)" kernel modules,
+ * we are safe to fail such module request from crypto_larval_lookup().
+ *
+ * In this way we prevent modprobe execution during digsig verification
+ * and avoid possible deadlock if modprobe and/or it's dependencies
+ * also signed with digsig.
+ */
+int integrity_kernel_module_request(char *kmod_name)
+{
+ if (strncmp(kmod_name, "crypto-pkcs1pad(rsa,", 20) == 0)
+ return -EINVAL;
+
+ return 0;
+}