From: Thorsten Blum <thorsten.blum@linux.dev>
Date: Sat, 3 May 2025 13:25:36 +0000 (+0200)
Subject: ovl: Annotate struct ovl_entry with __counted_by()
X-Git-Tag: v6.16-rc1~22^2
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=6f9ccdad0feaef58b05f07e0fc9d31004147177c;p=linux-block.git

ovl: Annotate struct ovl_entry with __counted_by()

Add the __counted_by() compiler attribute to the flexible array member
'__lowerstack' to improve access bounds-checking via CONFIG_UBSAN_BOUNDS
and CONFIG_FORTIFY_SOURCE.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
---

diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h
index cb449ab310a7..afb7762f873f 100644
--- a/fs/overlayfs/ovl_entry.h
+++ b/fs/overlayfs/ovl_entry.h
@@ -51,7 +51,7 @@ struct ovl_path {
 
 struct ovl_entry {
 	unsigned int __numlower;
-	struct ovl_path __lowerstack[];
+	struct ovl_path __lowerstack[] __counted_by(__numlower);
 };
 
 /* private information held for overlayfs's superblock */