ima: ima_api: Use struct_size() in kzalloc()
diff mbox series

Message ID 20190829172916.GA10261@embeddedor
State New
Headers show
Series
  • ima: ima_api: Use struct_size() in kzalloc()
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Commit Message

Gustavo A. R. Silva Aug. 29, 2019, 5:29 p.m. UTC
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(-)

Patch
diff mbox series

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;