[PATCH v8 6/8] certs: add wrapper function to check blacklisted binary hash

From: Nayna Jain
Date: Sat Oct 19 2019 - 14:07:04 EST


The -EKEYREJECTED error returned by existing is_hash_blacklisted() is
misleading when called for checking against blacklisted hash of a
binary.

This patch adds a wrapper function is_binary_blacklisted() to return
-EPERM error if binary is blacklisted.

Signed-off-by: Nayna Jain <nayna@xxxxxxxxxxxxx>
Reviewed-by: Mimi Zohar <zohar@xxxxxxxxxxxxx>
---
certs/blacklist.c | 9 +++++++++
include/keys/system_keyring.h | 6 ++++++
2 files changed, 15 insertions(+)

diff --git a/certs/blacklist.c b/certs/blacklist.c
index ec00bf337eb6..6514f9ebc943 100644
--- a/certs/blacklist.c
+++ b/certs/blacklist.c
@@ -135,6 +135,15 @@ int is_hash_blacklisted(const u8 *hash, size_t hash_len, const char *type)
}
EXPORT_SYMBOL_GPL(is_hash_blacklisted);

+int is_binary_blacklisted(const u8 *hash, size_t hash_len)
+{
+ if (is_hash_blacklisted(hash, hash_len, "bin") == -EKEYREJECTED)
+ return -EPERM;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(is_binary_blacklisted);
+
/*
* Initialise the blacklist
*/
diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h
index c1a96fdf598b..fb8b07daa9d1 100644
--- a/include/keys/system_keyring.h
+++ b/include/keys/system_keyring.h
@@ -35,12 +35,18 @@ extern int restrict_link_by_builtin_and_secondary_trusted(
extern int mark_hash_blacklisted(const char *hash);
extern int is_hash_blacklisted(const u8 *hash, size_t hash_len,
const char *type);
+extern int is_binary_blacklisted(const u8 *hash, size_t hash_len);
#else
static inline int is_hash_blacklisted(const u8 *hash, size_t hash_len,
const char *type)
{
return 0;
}
+
+static inline int is_binary_blacklisted(const u8 *hash, size_t hash_len)
+{
+ return 0;
+}
#endif

#ifdef CONFIG_IMA_BLACKLIST_KEYRING
--
2.20.1