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Subject[PATCH] afs: security: Use struct_size() in kzalloc()
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 foo {
int stuff;
void *entry[];
};

instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

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_KERNEL);

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
fs/afs/security.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/afs/security.c b/fs/afs/security.c
index 5f58a9a17e69..4e9a6c96b9e8 100644
--- a/fs/afs/security.c
+++ b/fs/afs/security.c
@@ -197,8 +197,7 @@ void afs_cache_permit(struct afs_vnode *vnode, struct key *key,
* yet.
*/
size++;
- new = kzalloc(sizeof(struct afs_permits) +
- sizeof(struct afs_permit) * size, GFP_NOFS);
+ new = kzalloc(struct_size(new, permits, size), GFP_NOFS);
if (!new)
goto out_put;

--
2.20.1
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