[PATCH 3/5] ima: Fix ima digest hash table key calculation

[Roberto Sassu]

From: Krzysztof Struczynski <krzysztof.struczynski at huawei.com>

Function hash_long() accepts unsigned long, while currently only one byte
is passed from ima_hash_key(), which calculates a key for ima_htable. Use
more bytes to avoid frequent collisions.

Length of the buffer is not explicitly passed as a function parameter,
because this function expects a digest whose length is greater than the
size of unsigned long.

Cc: stable at vger.kernel.org
Fixes: 3323eec921ef ("integrity: IMA as an integrity service provider")
Signed-off-by: Krzysztof Struczynski <krzysztof.struczynski at huawei.com>
---
 security/integrity/ima/ima.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 64317d95363e..cf0022c2bc14 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -177,7 +177,7 @@ extern struct ima_h_table ima_htable;
 
 static inline unsigned long ima_hash_key(u8 *digest)
 {
-	return hash_long(*digest, IMA_HASH_BITS);
+	return hash_long(*((unsigned long *)digest), IMA_HASH_BITS);
 }
 
 #define __ima_hooks(hook)		\
-- 
2.17.1