From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: Mimi Zohar <zohar@linux.ibm.com>,
Dmitry Kasatkin <dmitry.kasatkin@gmail.com>,
James Morris <jmorris@namei.org>,
"Serge E. Hallyn" <serge@hallyn.com>
Cc: linux-integrity@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org,
"Gustavo A. R. Silva" <gustavo@embeddedor.com>
Subject: [PATCH] ima: ima_api: Use struct_size() in kzalloc()
Date: Thu, 29 Aug 2019 12:29:16 -0500 [thread overview]
Message-ID: <20190829172916.GA10261@embeddedor> (raw)
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:
struct ima_template_entry {
...
struct ima_field_data template_data[0]; /* template related data */
};
instance = kzalloc(sizeof(struct ima_template_entry) + count * sizeof(struct ima_field_data), GFP_NOFS);
Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:
instance = kzalloc(struct_size(instance, entry, count), GFP_NOFS);
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
security/integrity/ima/ima_api.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 65224474675b..610759fe63b8 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -45,8 +45,8 @@ int ima_alloc_init_template(struct ima_event_data *event_data,
else
template_desc = ima_template_desc_current();
- *entry = kzalloc(sizeof(**entry) + template_desc->num_fields *
- sizeof(struct ima_field_data), GFP_NOFS);
+ *entry = kzalloc(struct_size(*entry, template_data,
+ template_desc->num_fields), GFP_NOFS);
if (!*entry)
return -ENOMEM;
--
2.23.0
reply other threads:[~2019-08-29 17:48 UTC|newest]
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