diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index f6d4d5810cc1e20bc6aeb2c054b80f2e71f55f5a..f573cad72b7e2784b0be6ba5c7535a0c5545e8aa 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2798,7 +2798,7 @@ static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
 		struct rcu_string *name;
 
 		name = rcu_dereference(dev->name);
-		strncpy(di_args->path, name->str, sizeof(di_args->path));
+		strncpy(di_args->path, name->str, sizeof(di_args->path) - 1);
 		di_args->path[sizeof(di_args->path) - 1] = 0;
 	} else {
 		di_args->path[0] = '\0';