[PATCH 3.18 18/26] ima: fix hash algorithm initialization

From: Greg Kroah-Hartman
Date: Thu Dec 07 2017 - 07:51:35 EST


3.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Boshi Wang <wangboshi@xxxxxxxxxx>


[ Upstream commit ebe7c0a7be92bbd34c6ff5b55810546a0ee05bee ]

The hash_setup function always sets the hash_setup_done flag, even
when the hash algorithm is invalid. This prevents the default hash
algorithm defined as CONFIG_IMA_DEFAULT_HASH from being used.

This patch sets hash_setup_done flag only for valid hash algorithms.

Fixes: e7a2ad7eb6f4 "ima: enable support for larger default filedata hash algorithms"
Signed-off-by: Boshi Wang <wangboshi@xxxxxxxxxx>
Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
security/integrity/ima/ima_main.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -52,6 +52,8 @@ static int __init hash_setup(char *str)
ima_hash_algo = HASH_ALGO_SHA1;
else if (strncmp(str, "md5", 3) == 0)
ima_hash_algo = HASH_ALGO_MD5;
+ else
+ return 1;
goto out;
}

@@ -61,6 +63,8 @@ static int __init hash_setup(char *str)
break;
}
}
+ if (i == HASH_ALGO__LAST)
+ return 1;
out:
hash_setup_done = 1;
return 1;