From: Thorsten Blum <thorsten.blum@linux.dev>
Date: Wed, 15 Apr 2026 12:25:45 +0000 (+0200)
Subject: lib/string_helpers: annotate struct strarray with __counted_by_ptr
X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=8f64fb098a5b1dfea57989fdf732b6168f0e1c35;p=thirdparty%2Flinux.git

lib/string_helpers: annotate struct strarray with __counted_by_ptr

Add the __counted_by_ptr() compiler attribute to 'array' to improve
bounds checking via CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Link: https://patch.msgid.link/20260415122542.370926-6-thorsten.blum@linux.dev
Signed-off-by: Kees Cook <kees@kernel.org>
---

diff --git a/lib/string_helpers.c b/lib/string_helpers.c
index 6a8db441b6fd1..98d6ed0eaab7e 100644
--- a/lib/string_helpers.c
+++ b/lib/string_helpers.c
@@ -805,7 +805,7 @@ void kfree_strarray(char **array, size_t n)
 EXPORT_SYMBOL_GPL(kfree_strarray);
 
 struct strarray {
-	char **array;
+	char **array __counted_by_ptr(n);
 	size_t n;
 };
 
@@ -824,13 +824,13 @@ char **devm_kasprintf_strarray(struct device *dev, const char *prefix, size_t n)
 	if (!ptr)
 		return ERR_PTR(-ENOMEM);
 
+	ptr->n = n;
 	ptr->array = kasprintf_strarray(GFP_KERNEL, prefix, n);
 	if (!ptr->array) {
 		devres_free(ptr);
 		return ERR_PTR(-ENOMEM);
 	}
 
-	ptr->n = n;
 	devres_add(dev, ptr);
 
 	return ptr->array;