linux-kernel - [PATCH v2] params: Replace deprecated strcpy() with strscpy() and memcpy()

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Message-ID: <20250813132200.184064-2-thorsten.blum@linux.dev>
Date: Wed, 13 Aug 2025 15:21:59 +0200
From: Thorsten Blum <thorsten.blum@...ux.dev>
To: Petr Pavlu <petr.pavlu@...e.com>,
	Thomas Weißschuh <linux@...ssschuh.net>,
	Shyam Saini <shyamsaini@...ux.microsoft.com>,
	Luis Chamberlain <mcgrof@...nel.org>,
	Dmitry Antipov <dmantipov@...dex.ru>,
	Thorsten Blum <thorsten.blum@...ux.dev>
Cc: linux-kernel@...r.kernel.org
Subject: [PATCH v2] params: Replace deprecated strcpy() with strscpy() and memcpy()

strcpy() is deprecated; use strscpy() and memcpy() instead.

In param_set_copystring(), we can safely use memcpy() because we already
know the length of the source string 'val' and that it is guaranteed to
be NUL-terminated within the first 'kps->maxlen' bytes.

Link: https://github.com/KSPP/linux/issues/88
Signed-off-by: Thorsten Blum <thorsten.blum@...ux.dev>
---
Changes in v2:
- Use memcpy() in param_set_copystring() as suggested by Petr Pavlu
- Link to v1: https://lore.kernel.org/lkml/20250810214456.2236-1-thorsten.blum@linux.dev/
---
 kernel/params.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/kernel/params.c b/kernel/params.c
index b92d64161b75..b96cfd693c99 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -513,13 +513,14 @@ EXPORT_SYMBOL(param_array_ops);
 int param_set_copystring(const char *val, const struct kernel_param *kp)
 {
 	const struct kparam_string *kps = kp->str;
+	const size_t len = strnlen(val, kps->maxlen);
 
-	if (strnlen(val, kps->maxlen) == kps->maxlen) {
+	if (len == kps->maxlen) {
 		pr_err("%s: string doesn't fit in %u chars.\n",
 		       kp->name, kps->maxlen-1);
 		return -ENOSPC;
 	}
-	strcpy(kps->string, val);
+	memcpy(kps->string, val, len + 1);
 	return 0;
 }
 EXPORT_SYMBOL(param_set_copystring);
@@ -841,7 +842,7 @@ static void __init param_sysfs_builtin(void)
 		dot = strchr(kp->name, '.');
 		if (!dot) {
 			/* This happens for core_param() */
-			strcpy(modname, "kernel");
+			strscpy(modname, "kernel");
 			name_len = 0;
 		} else {
 			name_len = dot - kp->name + 1;
-- 
2.50.1