[PATCH] initramfs: Use struct_size() helper to improve dir_add()

[PATCH] initramfs: Use struct_size() helper to improve dir_add()

[Thorsten Blum]

Use struct_size() to calculate the number of bytes to allocate for a new
directory entry.  No functional changes.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
 init/initramfs.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/init/initramfs.c b/init/initramfs.c
index 6745e3fbc7ab..6ddbfb17fb8f 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -19,6 +19,7 @@
 #include <linux/init_syscalls.h>
 #include <linux/umh.h>
 #include <linux/security.h>
+#include <linux/overflow.h>
 
 #include "do_mounts.h"
 #include "initramfs_internal.h"
@@ -152,7 +153,7 @@ static void __init dir_add(const char *name, size_t nlen, time64_t mtime)
 {
 	struct dir_entry *de;
 
-	de = kmalloc(sizeof(struct dir_entry) + nlen, GFP_KERNEL);
+	de = kmalloc(struct_size(de, name, nlen), GFP_KERNEL);
 	if (!de)
 		panic_show_mem("can't allocate dir_entry buffer");
 	INIT_LIST_HEAD(&de->list);
-- 
2.51.0

Re: [PATCH] initramfs: Use struct_size() helper to improve dir_add()

[Christian Brauner]

On Fri, 12 Sep 2025 08:52:57 +0200, Thorsten Blum wrote:
> Use struct_size() to calculate the number of bytes to allocate for a new
> directory entry.  No functional changes.
> 
> 

Applied to the vfs-6.18.misc branch of the vfs/vfs.git tree.
Patches in the vfs-6.18.misc branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs-6.18.misc

[1/1] initramfs: Use struct_size() helper to improve dir_add()
      https://git.kernel.org/vfs/vfs/c/e60625e7ce10