bpf: mark a NULL kfunc argument precisegrafted

check_kfunc_arg() allows bpf_register_is_null() for nullable arguments
w/o marking the underlying scalar register precise. Hence a checkpoint
created on such a path would prune against arbitrary scalar value.

Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 42 insertions, 0 deletions

diff --git a/fs/autofs/init.c b/fs/autofs/init.c
new file mode 100644
index 000000000..1d644a35f
--- /dev/null
+++ b/fs/autofs/init.c
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include "autofs_i.h"
+
+struct file_system_type autofs_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "autofs",
+	.init_fs_context = autofs_init_fs_context,
+	.parameters	= autofs_param_specs,
+	.kill_sb	= autofs_kill_sb,
+};
+MODULE_ALIAS_FS("autofs");
+MODULE_ALIAS("autofs");
+
+static int __init init_autofs_fs(void)
+{
+	int err;
+
+	autofs_dev_ioctl_init();
+
+	err = register_filesystem(&autofs_fs_type);
+	if (err)
+		autofs_dev_ioctl_exit();
+
+	return err;
+}
+
+static void __exit exit_autofs_fs(void)
+{
+	autofs_dev_ioctl_exit();
+	unregister_filesystem(&autofs_fs_type);
+}
+
+module_init(init_autofs_fs)
+module_exit(exit_autofs_fs)
+MODULE_DESCRIPTION("Kernel automounter support");
+MODULE_LICENSE("GPL");