strncpy() is deprecated for NUL-terminated destination buffers. Use
strscpy() instead and don't zero-initialize the param array.

Compile-tested only.

Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
Changes in v2:
- Use strscpy() instead of strscpy_pad() as suggested by David Sterba
- Link to v1: https://lore.kernel.org/r/20250225092949.287300-2-thorsten.blum@linux.dev/
---
 fs/btrfs/sysfs.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 53b846d99ece..14f53f757555 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -1330,13 +1330,13 @@ MODULE_PARM_DESC(read_policy,
 
 int btrfs_read_policy_to_enum(const char *str, s64 *value_ret)
 {
-	char param[32] = { 0 };
+	char param[32];
 	char __maybe_unused *value_str;
 
 	if (!str || strlen(str) == 0)
 		return 0;
 
-	strncpy(param, str, sizeof(param) - 1);
+	strscpy(param, str);
 
 #ifdef CONFIG_BTRFS_EXPERIMENTAL
 	/* Separate value from input in policy:value format. */
-- 
2.48.1

On Tue, Feb 25, 2025 at 08:26:14PM +0100, Thorsten Blum wrote:
> strncpy() is deprecated for NUL-terminated destination buffers. Use
> strscpy() instead and don't zero-initialize the param array.
> 
> Compile-tested only.
> 
> Link: https://github.com/KSPP/linux/issues/90
> Cc: linux-hardening@vger.kernel.org
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>

Added to for-next, thanks.